GBE Insulation Properties (Materials) G#16067

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Insulation Properties Materials

Insulating Properties Materials (Navigation)

Scope: Retrofit & New Build

  • Heat & Thermal Insulation Properties Jargon Buster (Navigation)
  • Insulating Material Properties (Navigation)
  • Insulation Applications (Navigation)
  • Insulation Choice of Materials (Navigation)
  • Insulation Accessories and Components (Navigation)
  • Insulation Application (Navigation)
  • Finishes (Navigation)
  • Decoration (Navigation)

Heat & Thermal Insulation Properties (Jargon Buster Theme) (Navigation)

  • Heat
  • Heat Movement
  • Eddy Currents
  • Convection Resistance
  • Conductivity Resistance
  • Solar Radiation Resistance
  • Thermal Bridge
  • Thermal bypass or flanking
  • Wind washing
  • Radiation
  • Solar Radiation Reflection
  • Long pathways
  • Emissivity Resistance
  • Surface Resistivity
  • Surface Emissivity
  • Heat flux

Heat: (Jargon Buster)

  • Heat is the result of a material’s molecules vibrating
  • Heated materials can warm adjacent materials by its vibrating molecules vibrating the adjacent material’s molecules and heat can transfer through the material (by conduction) and eventually through an assembly of materials
  • Some materials will permit the heat to transfer more readily and others more slowly.
  • Heat can also transfer by radiation across gaps between materials or even through low density materials
  • When some materials are hot they can change their phase from solid to liquid or from liquid to gas (Phase change materials) in doing so heat is transferred from the solid to the liquid or from the liquid to the gas
  • Water can turn from ice to water and from water to steam or moisture vapour when heated
  • When some materials are hot they can move about more freely, contact and warm other materials
  • When some materials are hot they can pass through other materials
  • Water moisture vapour can pass through building fabric, where it can be cooled by other cooler materials and condense back to water

Heat movement (Jargon Buster)

  • Heat gain, heat storage, heat movement and heat loss from a building works in a number of different ways
  • Reflection of the suns rays from the building’s surfaces
  • Radiation from the sun through glass and opaque building fabric and radiation from warmed surfaces
  • Convection from warmed floors or radiators warming the air
  • Conduction through building elements and their component materials
  • Flanking getting around insulation via air spaces or thermal bridges
  • Bypassing insulation through thermal bridges
  • Eddy Currents within air spaces
  • There are many ways to resist them: some use conventional thermal insulation and others use other material properties: like decrement delay, vacuum, thermal mass, etc. with varying degrees of success.

Eddy currents: (Jargon Buster)

  • Heat in open air or voids can rise and coolth in air or voids can fall, they can replace each other if in close proximity and set up circulating air currents in air or voids, called eddy currents.
  • Eddy currents can help dissipate heat
  • Heat on one side of insulation can be circulated by eddy currents within the material if the material is relatively open fibred or open celled

Convection Resistance (Jargon Buster)

  • Insulation that stops air circulating can hold warm air stationery and stop heat dissipation

Thermal Conductivity (Jargon Buster)

  • Materials with high density often (but not always) permit heat to flow through them
  • Copper is a very good thermal conductor (and electricity conductor)
  • Steel is a good thermal conductor (and good electrical conductor)
  • Stainless steel is a poor thermal conductor
  • Building fabric needs to have low thermal conductivity
    • to prevent heat loss or cool gain in winter
    • to prevent heat gain or cool loss in summer

Conductivity Resistance (Jargon Buster)

  • Air held still helps to stop heat loss by dissipation,
  • Air trapped in the cells or between fibres of insulation materials is held still and stops heat loss.
  • Usually low density materials where heat transfers through the fibre or substance of the material
  • Recognised by the Building Regulations and their compliance schemes.

Solar Radiation Resistance (Jargon Buster)

  • Higher density thermal insulation materials with relatively poor conductivity resistance
  • Heat transfer by Conductivity is slower in these materials
  • The time it takes to transfer from one side of the material to the other is Decrement Delay

Thermal Bridge (Jargon Buster)

  • (previously know as cold bridge, but there are also hot bridges, hence thermal bridge)
  • where a high conductivity material or component passes through a low conductivity material
  • provides a route for heat loss or coolth gain and risk of interstitial or surface condensation

Thermal bypass or flanking (Jargon Buster)

  • Where heat finds a way to bypass thermal insulation by finding a route of less resistance though open air, voids or thermal bridges, for example.

Wind washing (Jargon Buster)

  • Cold air from outside entering a roof through eaves ventilation slots and hitting open celled or open fibred insulation and washing the heat our of the fibres, drawing more heat out of the ceiling insulation.
  • Ventilation air movement in ventilated cavities with partial fill cavity insulation with an open fibre or open celled surface insulation; will draw heat out of the surface of the insulation and cool it down, drawing more heat from the wall.

Radiation (Jargon Buster)

  • Heat transfer by radiating across air spaces or air cavities in materials or air cavities between materials

Solar Radiation Reflection (Jargon Buster)

  • Reflective materials have more or less effect on sunlight
  • Aluminium foil (the flatter the better) (more effect) in some multi-foil insulation
  • Aluminised polyethylene (less effect than aluminium) common in multi-foil insulation
  • Mirror glass (more effect)
  • Smooth glass (less effect that mirror glass)

Long pathways (Jargon Buster)

  • Higher density materials with higher conductivity can be compensated for by having long pathways through the material e.g. a highly cellular material with long path ways through the wall of the cells

Emissivity Resistance (Jargon Buster)

  • Low emissivity (Low E) glazing has electrolytic coatings on one surface of the glass to reduce emissivity heat losses keeping the heat in the building

Surface Resistivity (Jargon Buster)

  • All external building elements (walls, roofs, soffits) exhibit a resistance to heat escaping from their surfaces and are permitted a value for surface resistivity in U value calculations.
  • Internal surface resistivity also happens and it too should be included in calculations.

Surface Emissivity (Jargon Buster)

  • Different materials have different surface emissivity and modify the rate at which heat leaves the surface of those materials
  • Infrared Thermography images may indicate an anomaly but the images need to be interpreted by visiting the building in daylight to see if the anomaly is heat loss or high emissivity materials at the surface.
  • New materials are bring invented with low emissivity that can be so hot they could burn skin on contact but with modified low surface emissivity will not burn on contact.
  • Will this property help with reducing heat loss from building facades?

Heat flux (Jargon Buster)

  • The rate of heat flow from a surface
  • Special materials are being developed that can be very high temperature (will burn fingers) but can be touched by fingers without being burned because they have a low heat flux surface

Insulating material properties (Navigation)


See Also:

  • Conductivity
  • Convection
  • Radiation
  • Reflection
  • Surface Resistivity
  • Surface Emissivity
  • Low emissivity surfaces
  • Density: Lightweight v heavyweight
  • Thermal mass
  • Specific Heat Capacity
  • Decrement Factor
  • Open v Closed cell
  • Moisture Vapour Open
  • Moisture Vapour Closed
  • Moisture Vapour Permeable
  • Moisture Vapour Resistant
  • Air/Wind Leakiness
  • Air/Wind tightness
  • Acoustic mass
  • Hydrophobic
  • Hygroscopic
  • Hydrophilic
  • Moisture Mass
  • Phase Change Materials (PCMs)

Fire Performance (Navigation)

  • Resistance
  • ‘Rated’
  • Combustibility
  • Surface Spread of Flame
  • Class 0

Insulating material properties


  • Heat can be lost from a building to the exterior by heat transferring through materials by conductivity
  • Dense materials are usually more conductive
  • Fire clay brick masonry is more dense and more conductive
  • Less dense materials are usually less conductive
  • Insulations materials are less dense and less conductive


  • Hot air rises, given the chance, but if you prevent it then you can keep it where you want it.
  • Putting insulation over the top of its source can help
  • Insulation with dense and closed surfaces will help to prevent warm air in the insulation air voids from escaping or being drawn out and being blow away by necessary ventilation
  • Wind washing caused by necessary eaves ventilation, can wash away the heat released by insulation making way for more heat to escape
  • Dense surfaces to materials, closed cells and foil faced materials can all help to reduce heat loss from the surface


  • Insulation with aluminium foil on their surfaces claim some advantages
    • Closed surfaces help to prevent heat being drawn out of the open or closed cells at the surface
    • Low emissivity surfaces radiate less heat from the surface
  • Multi layer foil insulation markets wonderful properties based on:
    • Low radiation from low emissivity surfaces
    • Use of surface resistivity cavities in construction voids
    • Reflection of heat back inwards


  • The world had an albedo or Light Reflectance Value (LRV) of 0.39
  • Ideally buildings should be lighter that this.
  • Light coloured roof can reflect solar radiation heat
  • White spar chippings were the order of the day for flat roofs
    • Today we see them specified less frequently
    • Mineral coated membranes replaced them
  • Solar reflective paint in white or silver
    • Short life high maintenance meant they are not popular
    • America is seeing a resurgence in white painted roofs
  • Light coloured single ply roofing
  • Paving slabs need to be white or light coloured
  • Gravel or pebbles have played their part but white pebbles are in short supply
  • Metal roof can reflect some heat but weathering patination will dull them down
    • Metal roof offer little protection from solar gain
    • Mineral wool or plastic insulation does nothing to improve it
  • Architect’s two favourite colours: RAL 9010 white and RAL 9006 Gatwick Silver
    • Help with cladding and curtain walling
  • Insulation: use high decrement delay factor insulation
  • Multi layer foil insulation marketeers promote wonderful properties based on:
    • Low radiation of heat from low emissivity external surfaces
    • Reflection of heat back inwards

Surface Resistivity

  • Surface resistivity at inner and outer surfaces of building elements
  • the material surface and the air space adjacent to it offer added insulation to the element
  • Internal resistivity and external resistivity
  • Resists some heat from being drawn out of surface of insulation
  • Foil face also air tight, if joints are airtight profile and/or tape sealed
  • See BS EN ISO 6964
  • See GBE Whole Building Calculator Worksheet: Resistances and Elements

Surface Emissivity

  • Outer and inner faces
    • of walls, roofs, floors
  • Ability to absorb or release heat
  • Zone outside of material’s face
    • is part of this property
  • Emissivity level
    • depends on the material at the surface
    • Reflective foils can reduce some heat loss
    • Steel trough formwork to concrete floor
      • Prevents exploitation of thermal mass

Low emissivity surfaces

  • Foil face
    • E.g. Aluminium, Aluminised polyethylene
  • Low radiation from surface
  • Heat reflection back inwards
  • Need air space adjacent to them to be effective
  • Probably needs space both sides
  • Takes up a lot of space that could have been insulation

Density: Lightweight v Heavyweight

  • Light can mean lots of trapped air inside
  • Light weight can be insulating
  • Light weight may not be able to absorb heat or store it
  • v
  • Heavy can mean less trapped air inside
  • Heavyweight can be less insulating
  • Heavyweight may be able to absorb heat, store it and releasing later

Thermal mass

  • Not normally associated with insulation materials but with adjacent building fabric, e.g. concrete, masonry,
  • Dense materials with ability to absorb heat from warmed air or absorb solar radiant heat or other radiant heat
  • Larger surface area is most useful since heat will be absorbed through the surface and slowly conducted into the thickness
  • Because the sun moves during the day the time the surface is exposed to the sun is limited by the building’s geometry
  • Once the sun has moved away then the surface can reradiate the heat into the now cooler space
  • Thickness really becomes useful over longer periods of warmer days and warm nights
  • Thickness becomes useful as an Inter-seasonal thermal store
    • saving summer heat for 6 months and releasing for 6 months in the winter,
    • this requires thermal storage beyond the building within subsoil and corralled by thermal insulation

Specific Heat Capacity

  • Materials with this property are able to absorb heat and hold it in their substance
  • Some materials can soak up considerable heat energy
    • Cellular glass insulation
    • Dense wood fiber
    • Cellulose flake
    • Cork
    • Hemp-Lime
    • Most plant-based insulation materials
    • Clay Plaster
    • Cement Render
    • Wood Fibre Cement Particle Board
    • Cement Sand Screed materials
    • Stone Brick Block materials
    • Concrete
    • Phase Change materials (because of Phase Change Properties as well)

Decrement Factor

  • The ability of a material to absorb and store solar or other radiant heat
  • The heat warms up the cells to thermal saturation
  • The heat warms up the thickness of the material by conduction
  • Then radiates out of the inside face into the space beyond
  • Decrement delay is the time all this takes to happen
  • Decrement delay helps prevent building interiors from overheating on sunny days

Open v Closed Cell

  • Closed cell: holds air stable
  • Cell size makes a difference
    • Big cells let air circulate in Eddie currents and enables heat transfer to next cell
    • Smaller cells make more stable air and offer more cells and cell walls for heat to cross
  • Trapped static air:
    • = insulation k and R values
  • Open celled:
    • Air, moisture vapour and heat permeable,
    • Vapour open = part of ‘breathing’

Moisture Vapour Open (VO)

Moisture Vapour Closed (VC)

Moisture Vapour Permeable

Moisture Vapour Resistant

Enhanced Vapour Transfer (EVT)

Air/Wind leakiness

  • Air movement through building fabric
  • Air movement through building fabric carrying heat or coolth with it
  • Air movement through air permeable materials e.g. mineral fibre insulation
  • Foamed in sealants are prone to leakiness
    • Gaps that are inaccessible are foamed
    • Surfaces that are inaccessible cannot be dried, cleaned, loose material removed nor primed
    • Foaming sealants will expand against those surfaces and seal initially
    • Foaming sealants are prone to shrinkage after initial expansion
    • They and will pull away from unprepared surfaces creating gaps for air and wind leakage

Air/Wind Tightness

  • No or Slow air movement through building fabric
  • No or Slow heat in that air movement through building fabric
  • No gaps between components of elements of construction
  • No air permeable materials in construction
  • Air and wind tight membranes within elemental assemblies
  • Air and wind tight self adhesive tapes along joints in materials
  • Air and wind tight sealants bonding materials together at abutments
  • Grommets and sleeves around services passing through elements and penetrating membranes

Acoustic Mass

  • Acoustic construction relied on materials mass historically
  • Long pathway differences were also relied upon
  • Fiduciary rule dictated cheaper solutions were needed and manufacturers discovered that lightweight constructions assemblies could be made to achieve good and better performance than heavy weight ones.
  • Some lightweight materials were also found to have good or better acoustic performance
  • Some medium density materials can also have considerably better acoustic performance than the lightweight ones; they include:
    • Dense wood fiber
    • Cork
    • Cellular glass


  • Hydro = water
  • Phobic = Does not like, rejects
  • Will not absorb water but can adsorb onto surface of fibres
  • Mineral fibres will not absorb water into fibres
    • So airspaces will be occupied by water
    • Preventing insulation function of air spaces
  • Hydrophobic materials are not suitable in vapour open construction
  • Hydrophobic materials are suitable in vapour closed construction
  • Plastics suitable in inverted roof or foundation construction
  • But some plastics have been found to contain water after prolonged exposure


  • Hygro = moisture vapour
  • Scopic = likes, absorbs into fibre, (not adsorbs onto surface)
  • Draws moisture from air spaces into fibres so air space can insulate
  • Hygroscopic materials are suitable for vapour-open construction
  • Hygroscopic materials are also suitable for vapour-closed construction


Moisture Mass

Fire Performance (Navigation)

  • Resistance
  • Rating
  • Combustibility
  • Surface Spread of Flame (SSofF)
  • Class 0


  • The ability of a material to combust into flame under heat or flame exposure
  • UK test: is BS 476:Part 6
  • EU test: EN 13501-1
    • A1 = Non-combustible
    • A2 = Limited Combustibility
    • B = Low risk
      • (adds fuel to the file, releases smoke and releases smoldering droplets)
    • C = Medium Risk (ditto)
    • D = High Risk (ditto)
    • E & F = Very High Risk (ditto)

Surface Spread of Flame (SSofF)

  • Fire Performance or Property
  • Enables flames to move across surfaces
  • Depends on the materials at the surface
  • g. Aluminium foil bonded to materials
  • Reduces SSofF to BS 476:Part 7 Class 1
  • Flames to not spread easily
  • Damage the low SSofF surface and expose the substrate’s properties which may be worse SSofF

Class 0

  • UK Building Regulations Approved Document B
  • A combination of:
    • non-combustibility to BS 476:Part 6
    • low spread of flame to BS 476:Part 7
  • It may be one material or:
    • non combustible core
    • Combustible core
    • low surface spread of flame facing
  • Combination
  • Euro-Class EN 13501-1 Class C core is Medium Fire risk
    • A fuel in a fire situation if core is exposed
  • BS 476:Part 7 Class 1 Surface Spread of flame facing
  • If the facing is damaged in the construction stage
  • A fire will find the substrate and turn it into a fuel

Insulation Application (Navigation)

  • Foundation
  • Basement
    • Floor
    • Wall
    • Partition
  • Ground floor
    • Over basement
    • Suspended over void
    • Ground bearing
  • Wall
    • External wall
    • Internal partition
    • Compartment Wall
    • Compartment party wall
  • Upper floor
    • Over air
    • Internal
    • Compartment floor
    • Compartment Party floor
  • Roof
    • Flat roof
    • Pitched roof
    • Ceiling

Insulation: Choice of Materials (Navigation)

  • Air
    • Air spaces
    • Sealed Unit Glazing Air Spaces
    • Multi layer foils
    • Vacuum Insulated Panels
  • Fossil (Non-renewable Hydro-carbons)
    • Expanded or extruded Foamed plastic
    • High density polyethylene
    • Plastic fibre wool insulation
    • Sprayed foaming plastic
    • Sprayed Moisture vapour permeable foamed bio-plastic
    • Multi layer foils (see above)
  • Mineral
    • Mineral wool
    • Cellular ‘foamed’ glass
    • Cellular mineral
    • Extruded fired cellular mineral
    • Extruded cellular mineral
    • Calcium Silicate
    • Aerogel
  • Vegetable (Plant-based & Tree-based)
    • Cellulose Fibre Flake
    • Dense Wood Fibre
    • Medium Density Wood Fibre
    • Cork
    • Hemp
    • Cotton
    • Coconut Husk
    • Sprayed Moisture vapour permeable foamed bio-plastic (see Above)
    • Grass
  • Animal
    • Wool
    • Hair
    • Feather
  • Composites
    • Insulating plasters
    • Hemp-lime
    • Hemp-clay
    • Clay-Lime

Air spaces

  • Trap air
    • Holds spores
    • Holds moisture vapour
    • Holds VOCs and other air pollutants
  • Can be ventilated
    • To remove moisture vapour and pollutants
    • Facilitate wind washing to blow heat from surfaces
    • Increase air/wind leakiness
  • Fluctuates in temperature
    • Can draw heat from surfaces
    • Can warm surfaces
  • Can be a route for thermal flanking/thermal bypass
    • Can enable Eddie currents and stack effect
    • Can be a place for heat to dissipate into
  • Provide acoustic isolation
    • But surfaces can ‘talk’ across cavities
    • Double glazed units need different glass thicknesses to interfere with each other’s vibrations
  • Can separate inside from outside
    • Prevent capillary attraction (if wide enough) minimum 8 mm.
    • Prevent moisture transport

Sealed unit glazing air spaces

  • Two or more sheets of glass spaced apart creating a cavity
    • Contain dry air or other gases
    • Hermetically sealed at factory
    • Minimise risk of condensation inside unit
    • BSI Kitemarked (Quality mark)
  • Separated by
    • spacers at edge
      • With silicone desiccant to absorb moisture
      • Aluminium extrusions create thermal bridge
      • Plastic Soft edge spacer minimises thermal bridge
      • Glass edge moulded into two sheets
    • Spacers across glass
      • Used with vacuum sealed glass units
    • Spacing:
      • 2 mm vacuum for historic window upgrades
      • 4 mm slim-line for historic window upgrades
      • 12, 14, 16, 20 mm normal units
      • 50 – 60 mm double casement with encapsulated solar blinds
      • 200 mm Acoustic separation
    • Other gases
      • Dry Air
      • Argon
      • Krypton
      • Xeon
    • Embodied Energy (total for timber window 1.2 x 1.2 m DGSU)
      • Dry air or Argon: 230-490 MJ
      • Krypton: 740–1000 MJ
      • Xeon: 4730–4990 MJ
    • Embodied Carbon (total for window 1.2 x 1.2 m DGSU)
      • Dry air or Argon: 12-25 kg CO2
      • Krypton: 38-51 kg CO2
      • Xeon: 241-254 kg CO2
    • Images:
      • ICE Database [1 No. CI]
    • See Also
    • GBE Materials: Glass
      • Low E coatings
      • Solar Control coatings

Multilayer foil Insulation:

  • Low emissivity (theoretical calculations)
  • Needs air spaces both sides, for optimum performance
    • Both sides of each layer ideally
    • Both sides of the multi layer foil
  • Poor k value (optimistic literature) (Poor R and U values)
  • No thermal mass
    • No decrement delay
  • Vapour check (but pierced by stitching)
  • Reflective: need PPE: Eyes & skin
    • But radiant heat gets through in time
  • Use where architect’s details prevent use of anything else
  • Use where conservation officer prevent anything else (consider aerogel)
  • Don’t use on their own if you can avoid it
  • Potentially low LCA using high LCA materials
    • Plastics and aluminised plastics (high embodied carbon)
    • But very little material used
  • Combustibility: Plastic: EN 13501-1 E Very high risk

VIPs Vacuum Insulation Panels

  • Best k value available
  • Worst decrement delay available
  • Hollow aluminium foil, plastic spheres supporting structure, vacuum inside interstices
    • Foil edge and joints can let it down
    • Once punctured or cut do not work at all
    • Will not tolerate nails, screws or staples
  • Modular in nature
    • How do you deal with perimeters?
    • No modification on site
  • Made to order?
    • Is offered by 1 manufacturer of flat roof
  • High embodied energy and carbon
  • LCA EPD PEF (no information yet)

Non-renewable Fossil Hydro-carbons

Expanded or Extruded Foamed plastic

  • Closed cell
    • Not Moisture vapour permeable
    • Not moisture absorbent
  • Good k values
  • If foil faced
    • low emissivity
  • Vapour barriers essential in vulnerable construction (Vapour-closed)
    • Timber framed is vulnerable construction
  • No not use in Vapour-open construction
  • Combustibility: Plastic: EN 13501-1 F Very high risk
    • Flame retardant grades available
  • LCA EPD PEF: High

High Density Polystyrene

  • Closed cell
    • Not Moisture vapour permeable
    • Not moisture absorbent
  • Medium k values
  • Developed for embedding in concrete or masonry construction for robust fixing ground
    • With reduced thermal conductivity
  • Combustibility: Plastic: EN 13501-1 F Very high risk
  • LCA EPD PEF: High

Plastic fibre wool insulation

  • Hydrophobic
    • Performance diminished when moist
  • Middle of the road k values
  • Developed as a non-itch alternative to mineral wool
  • Open pore
    • Moisture vapour permeable
    • Air permeable
      • Heat permeable
    • Wind washing vulnerable
  • Combustibility: Plastic: EN 13501-1 F Very high risk
  • LCA EPD PEF: High

Sprayed foaming plastic

  • Good airtightness
  • Not moisture absorbent
  • Not Moisture vapour permeable
    • Will drive moisture through adjacent stuff
    • Can rot timber
  • Can entomb nature
  • Can be very unhealthy to sensitive people
  • Combustibility: Plastic: EN 13501-1 F Very high risk
    • Flame retardant grades available
  • LCA EPD PEF: High

Sprayed Moisture vapour permeable foamed bio-plastic

  • Good airtightness: fits accurately to the existing shapes
    • Until it shrinks
    • Can remain in a state of tension if bonded to surrounding surfaces
    • Can tear readily
    • Can be months later
  • Good k value
  • Moisture vapour permeable
  • Won’t rot timber
  • Can entomb nature
  • Combustibility: Plastic: EN 13501-1 F Very high risk
    • Flame retardant grades available
  • LCA EPD PEF: Middle
  • Bio-plastic versions rare in the market
  • Sustainably farmed crops sourcing hard to maintain

Mineral Insulating materials

Stone, slag and glass mineral wool:

  • Hydrophobic
    • Performance diminished when moist
  • Middle of the road k values
  • Low cost and used everywhere
    • Including all the wrong places
  • Wide range of densities for applications
  • Open pore
    • Moisture vapour permeable
    • Air permeable
      • Heat permeable
    • Wind washing vulnerable
  • Combustibility: Stone: EN 13501-1 A1 Non-Combustible or A2 limited combustibility
  • LCA EPD PEF: Middle

Cellular ‘foamed’ glass

  • Strong, loadbearing
  • High decrement delay
  • Poorer k values but remains effective
  • Moisture resistant
  • Vapour resistant
  • Dimensional stability
  • Frost vulnerable: Saturation possible
    • Should be protected by flood coat on roof
    • or membranes if buried
  • Combustibility: Stone: EN 13501-1 A1 Non-Combustible or A2 limited combustibility

Cellular mineral:

  • E.g. AAC Autoclaved Aerated Concrete
  • AC Aerated Concrete
  • Medium decrement value
  • Medium thermal mass
  • Closed cell
  • Airtight
  • Thermal bridge by mortar joints
  • Low moisture absorbency
  • Low Moisture vapour permeability/transport
  • Medium Load-bearing
  • Combustibility: Concrete: EN 13501-1 [________]

Extruded fired cellular mineral

  • Fired clay cellular block
  • Extruded:
    • Hollow cells hold air still
    • Long path way through cell walls
  • High decrement factor/delay:
  • High thermal mass at surface
  • Good load-bearing capacity
  • Thin bed joint: negligible thermal bridge
  • Air leaky perpends
    • Needs airtight coating: clay or lime plaster
  • Combustibility: Fired Clay: EN 13501-1 [________]

Extruded cellular mineral

  • Blockwork
  • Lime binder
  • Lightweight insulating pumice aggregate
  • Extruded:
    • hollow cells hold air still
    • Long path through cell walls
  • Medium thermal mass at surface
  • Medium decrement:
  • Lime mortar: neutral joint heat loss
  • Moisture management
  • Low load-bearing capacity
  • LCA EPD PEF: Low

Calcium silicate:

  • E.g. Calsitherm
  • Open cell,
    • Incredibly lightweight,
    • Moisture vapour permeable,
  • Capillary action
    • Moisture transport
  • Decrement delay
  • Discourages mould anti-bacterial
  • Developed for historic fabric compatibility as internal insulation
    • Has own adhesive and jointing material
  • LCA EPD PEF: Very low


  • E.g. Spacetherm by Proctor Group
  • Silica solution minus water
    • Microscopic air bubbles
    • Some fibre reinforced
  • Excellent k value (better than plastics)
  • Moisture vapour permeable
  • Moisture mass
  • Decrement delay
  • Expensive use sparingly
    • Available in minimum 5 mm multiple thicknesses
  • Used in thermal bridge solutions
    • At perimeters abutments of insulation
    • At services interfaces
    • At opening jambs
  • LCA EPD PEF: (no information yet)
  • Combustibility: EN 13501-1 a German product has A1 Certification

Vegetable (Plant and tree based):

  • Hygroscopic (absorbs moisture vapour)
  • Moisture Vapour: permeable
  • Density: High to low
  • Rigid: spanning
  • Soft: squeezy
  • Decrement delay: Medium to high
  • Acoustic insulation: Excellent
  • Fixing: Long fasteners needed: available in UK
    • Imported from Italy, etc.
  • LCA EPD PEF: Low
  • Carbon Negative (sequestration)

Cellulose Fibre Flake

  • Hygroscopic (absorbs moisture vapour)
  • Moisture vapour permeable
  • Density: High or low
  • Rigid: spanning
  • Soft: squeezy
  • Decrement Delay: Medium to High
  • Acoustic Insulation: Excellent
  • Long fasteners needed: available in UK
    • Imported from Italy, etc.
  • LCA EPD PEF: Low
  • Carbon Negative (sequestration)

Dense Wood Fiber

  • Hygroscopic (absorbs moisture vapour)
  • Moisture vapour permeable
  • Density: High or low
  • Rigid: spanning
  • Soft: squeezy
  • Decrement Delay: Medium to High
  • Acoustic Insulation: Excellent
  • Long fasteners needed: available in UK
    • Imported from Italy, etc.
  • LCA EPD PEF: Low
  • Carbon Negative (sequestration)

Medium Density Wood Fibre

  • Hygroscopic (absorbs moisture vapour)
  • Moisture vapour permeable
  • Density: High or low
  • Rigid: spanning
  • Soft: squeezy
  • Decrement Delay: Medium to High
  • Acoustic Insulation: Excellent
  • Long fasteners needed: available in UK
    • Imported from Italy, etc.
  • LCA EPD PEF: Low
  • Carbon Negative (sequestration)


  • Hygroscopic (absorbs moisture vapour)
  • Moisture vapour permeable
  • Density: High or low
  • Rigid: spanning
  • Soft: squeezy
  • High decrement delay
  • Acoustic Insulation: Excellent
  • LCA EPD PEF: Low
  • Carbon Negative (sequestration)
  • Combustibility: Cork: High flammability initially then chars and becomes fire resistant


  • Hygroscopic (absorbs moisture vapour)
  • Moisture vapour permeable
  • Low density
  • Soft: squeezy
  • Medium decrement delay
  • Acoustic Insulation: Excellent
  • LCA EPD PEF: Low
  • Carbon Negative (sequestration)


  • Hygroscopic (absorbs moisture vapour)
  • Moisture vapour permeable
  • Density: High or low settings
  • Sets Hard: needs a background for spraying against or formwork to fill
  • Decrement delay: High
  • Phase Change Material
  • Acoustic Insulation: Excellent when high density, poor if low density
  • LCA EPD PEF: Low (Hemp), Medium (lime)
  • LCA EPD PEF: Low (Hemp), High (cement/lime/aluminium oxide)
  • Carbon Negative (sequestration) (Hemp only)


  • Hygroscopic (absorbs moisture vapour)
  • Moisture vapour permeable
  • Low density
  • Soft: squeezy
  • Medium decrement delay
  • Acoustic Insulation: Excellent
  • LCA EPD PEF: Medium to high (Chemically intensive manufacture)
  • Carbon Negative (sequestration)

Coconut Husk

  • Hygroscopic (absorbs moisture vapour)
  • Moisture vapour permeable
  • Low density
  • Soft: squeezy
  • High decrement delay
  • Acoustic Insulation: Excellent
  • LCA EPD PEF: Low
  • Carbon Negative (sequestration)

Sprayed Moisture vapour permeable foamed bio-plastic (see Above)


  • Hygroscopic (absorbs moisture vapour)
  • Moisture vapour permeable
  • Low density
  • Soft: squeezy
  • Medium decrement delay
  • Acoustic Insulation: Excellent
  • LCA EPD PEF: Low
  • Carbon Negative (sequestration)

Animal (Navigation)

  • Wool
  • Hair
  • Feather

Insulation Accessories and Components (Navigation)

  • Vapour barriers (VB)/Vapour Control Layer (VCL)/Vapour Check (VC)
  • Breather membranes (BM)
  • Breathable Roofing Membrane (BRM)
  • Air tightness layer (ATL)
  • Wind tightness layer (WTL)
  • Breathing Sheathing Board (BSB)
  • Multi layer foil Breathing Roofing Membranes
  • Supporting Components

Vapour barriers (VB)/Vapour Control Layer (VCL)/Vapour Check (VC)

  • Used inside of insulation/construction
    • Used with Breather Membranes outside
  • Vapour resistant
    • Vapour check if inadequate
  • Leaks are inevitable
    • Leaks can be harmful
    • Sealing of leaks is exceptional
  • Compromise is inevitable
  • Compromise is unacceptable

Breather Membranes (BM)

  • Used outside of insulation/construction
    • Used with vapour barriers inside
  • Walls or roofs (framed constructions)
    • Weather protection (until covered)
  • Vapour permeable
    • Building paper
    • Polyethylene/Polyolefin
    • Can be ‘intelligent’
      • Properties vary with atmospheric moisture
    • Long protection fibres can be harmful to bats trough entanglement
    • Traditional bitumen impregnated fibre
      • Very few bats trapped in short fibres

Air tightness layer (ATL)

  • Used inside of insulation/construction
    • Used with wind tightness layer outside
    • Usually timber/metal framed
  • Materials:
    • Some paper and cellulose
    • Polyethylene/Polyolefin
  • Airtight
  • Vapour permeable
    • Can be ‘intelligent’:
      • Variable properties responding to atmospheric conditions

Wind tightness layer (WTL)

  • Used outside of insulation/construction
    • Used with air tightness layer inside
  • Materials: polymer
    • Polyethylene/Polyolefin
  • Vapour permeable
    • Can be ‘intelligent’
      • Properties vary with atmosphere
    • Wind tight
    • Weather resistant
    • Can be roofing underlay, often is

Breathable/Breathing Roofing Membranes (BRM)

  • Used outside of insulation/construction
    • Used with air tightness layer inside
  • Vapour permeable
    • Polyethylene/Polyolefin
    • Can be ‘intelligent’
      • Properties vary with atmosphere
    • Wind tight
    • Weather resistant
    • Currently under BCT investigation
      • Research on-going
      • So far all long chain fibres risk bat entanglement/entrapment/death by starvation

Breathing Sheathing boards (BSB)

  • Past: Bitumen Impregnated Fibre Board (BIFB)
  • Today: Timber with own natural binding agents
  • Used outside of insulation/construction
    • Used with air tightness layer inside
    • Often used outside of structural framing
  • Rigid and span over framing
    • Will hold insulation in stud/rafter zone
  • Vapour permeable
  • Wind tight
  • Weather resistant (some made of two grades, weather resistant outside)
  • Usually thermally insulating (but limited thickness)
  • Usually acoustically insulating (but limited thickness)
  • Can eliminate or reduce thermal bridges
    • Through structural framing
  • LCA EPD PEF: Low
  • Biogenic Sequestered Carbon

Multi layer foil Breathing Roofing Membranes (MBRM)

  • Used outside of insulation/construction
    • Used with vapour barriers inside
  • Vapour resistant but punctured by stitching: so vapour permeable
    • But may need a Condensation Risk Analysis before using
  • Wind tight but punctured by stitching
  • Weather resistant but punctured
  • Can be thermally insulating
  • Can be acoustically insulating
  • Can be reflective Sun glasses PPE
  • Has no decrement delay to exploit

Supporting Components Accessories (Navigation)

  • Netting (supporting insulation)
  • Meshes (supporting insulation)
  • Trays (supporting insulation)

Netting support to Insulation

  • Support thermal insulation in timber floors
  • Separate services from insulation
  • Avoid up-rating of electrical cables
  • Maintain void for down-lights
  • Stapled into place
  • Very complicated to install
    • Labour intensive, slow, inaccurate
    • Inconsistent insulation zone probable
    • Mesh slips and insulation is squeezed

Metal Meshes

  • Can exclude insects and permit others
  • Used to support insulation
  • Were recommended
    • for bats to hang from in place of BM or BRM
    • Sharp internal acute angles
    • Jagged cut edges
    • Can trap bats and birds
    • No longer recommended
  • High embodied Energy

Insulation support trays

  • Support thermal insulation in timber floors
  • Simplification of installation of insulation top or bottom of cavity
  • Separate services from insulation
  • Avoid up-rating of electrical cables
  • Maintain void for down-lights
  • Double skin polycarbonate, very thin
  • Scored for folding
  • Punched for air/moisture passage
  • Stapled into place
  • Liked by installers & all adjacent trades

Proofing Material Components (Navigation)

  • Damp proof membranes (DPM)
  • Damp/Gas proof membranes (D/GPM)
  • Damp proof but vapour permeable membranes (DPVPM)
  • Drainage/Trickle layers (DTL)
  • Cavity Fire & Smoke barriers (CF&SB)
  • Thermal Breaks (TB)

Damp proof membranes (DPM)

  • Below ground bearing floor
  • Below any thermal insulation
    • to keep it dry and effective
  • Ground water resistant
    • If joints lapped and bonded
  • Ground gas/vapour resistant
    • if joints lapped and bonded

Damp/Gas proof membranes (D/GPM)

  • Below ground bearing floor
  • Below any thermal insulation
    • to keep it dry and effective
  • Above any ventilation labyrinth
  • Ground water resistant
    • If joints lapped and bonded
  • Ground vapour resistant
    • If joints lapped and bonded
  • Ground gas resistant (Radon Methane)
    • If joints lapped and bonded

Damp proof but vapour permeable membranes (DPVPM)

  • g. Bentonite clay powder between geotextile layers
  • Sourced from USA
  • Below ground bearing floor
  • Below any thermal insulation
    • to keep it dry and effective
  • Ground water resistant
  • Ground vapour resistant only when wet
  • Ground vapour permeable when dry
  • Ground gas permeable (Radon Methane)

Drainage/Trickle Layers (DTL)

  • Below ground bearing floor
  • Below any thermal insulation
    • to keep it dry and effective
  • Allows water downwards
  • Resists ground water upward transport
  • Won’t stop water table rising
  • Not ground gas resistant
  • Not flood resistant

Thermal Break (Navigation)

  • Thermal Break: Foundation/External Wall
  • Thermal Break: Ground Floor/External wall
  • Thermal Break: External Cavity Wall Window/Door Opening Jamb Closer
  • Thermal Break: External Solid Wall Window/Door Opening Jamb Closer
  • Thermal Break: External Wall Lintels
  • Thermal Break: External Wall Cavity Ties
  • Thermal Break: External Wall Insulation (EWI) Perimeters

Thermal Break: Foundation/External Wall

  • Below ground cavity external wall
  • Cavity usually filled with concrete to ground level
  • To occupy space that could will with ground water
  • To prevent water getting into cavity insulation
  • To prevent thermal flanking through perimeter wall below ground floor
  • Cellular glass, bitumen coated, profiled
  • g. Foamglas Perinsul

Thermal Breaks (TB): Ground Floor/External wall

  • In loadbearing internal leaf of external walls
    • Aligned with floor insulation
  • To stop thermal flanking through wall at perimeter of building and internal walls and their abutments
  • g. Cellular glass and bitumen coating
  • g. Foamglas Perinsul
  • g. Extruded plastic with loadbearing metal posts

Thermal Break: External Cavity Wall Opening Jamb Closer

  • Linking inner leaf to outer leaf
  • Was: brick
  • Then: block inner leaf with block slithers
  • Always cutting and waste
  • Then: purpose made block return
  • Then: insulated/damp proof course/ties/opening former
    • PVC extrusions, expanded plastic filler
  • Now: wide cavities: avoid closers use plywood box frame and cavity insulation

Thermal Break: External Solid Wall Window/Door Opening Jamb Closer

  • In solid masonry external walls
  • Add high performance window/door
  • Add wall insulation:
    • external or internal
  • External or internal wall insulation needs to link up with high performance windows
  • But diagonal route for heat through wall avoids the insulation/window
  • Creates thermal bridge diagonally between window/door and internal/external insulation
  • External or internal insulated jamb lining thermal break
  • Insulated jambs: very little space so high performance is needed
  • g. Aerogel and lining board is used for thinness allowing windows to work unhindered
  • 5 to 20 mm Aerogel to jambs
  • g. Enviroform Solutions Ltd. Thermo Pro Bead

Thermal Break: External Wall Lintels

  • Hardwood
  • Concrete: precast, prestressed, insitu trough lintel thermal bridge
  • Extruded fired clay trough lintel
  • Steel compound sections
    • Steel thermal bridge
    • Insulated core (non functional)
    • 2 piece lintels: Plastic thermal break
  • Pultruded mineral/fibre reinforced
    • Limited span thermal break
  • Steel inner-pultruded outer composite

Thermal Break: External Wall Cavity Ties

  • Galvanized mild steel
    • Can be bent and galvanizing will fail
      • Have rusted away
    • Have been coated in plastic
      • Reacted with plastic foam cavity insulation
    • Stainless steel
      • Lower thermal conductivity than mild steel
      • Longer to suit wide cavity
      • 2 part, connected to complete
      • Sharp protrusion, risk of harm
    • Pultruded mineral/fibre rod & rubber ring drip
      • Lower thermal conductivity than stainless steel
      • BBA Agrément Certified available

Thermal Breaks: External Wall Insulation (EWI) Perimeters

  • Thick external wall insulation
  • Perimeters:
    • ground level,
    • above pitched or flat roof abutment,
    • eaves behind gutter
  • Services interfaces
    • Behind SW&VP
    • Behind Gutter and Downpipes
  • Foil wrapped Aerogel and powder coated interlocking metal profiles
  • g. Enviroform Solutions Ltd. Thermo Pro range
  • Any other interfaces
    • Plastic spacers
    • Avoid cobbled up softwood spacers

Cavity Barriers (Fire & Smoke)

  • Non-combustible materials
  • Used in construction containing cavities
  • To subdivide the cavity into small areas
  • To reduce risk of smoke, heat, fire, flashover or confined space explosion jumping from one cavity to another
  • Preventing the fire progressing from one part of the building to another
  • Cavity barrier through full thickness of insulation not just on their surfaces

External Envelope & Services Aperture Integrity

  • Outgoing:
    • Boiler Flues/Balanced Flues
    • Extractor Fans/with heat recovery
    • WC overflows
    • Soil Waste and vent Pipes
  • Incoming:
    • Power, Electricity,
    • Communications, Telephone,
    • Broadband, Cable, TV aerial, Satellite Dish
  • Holes cut, services inserted, aperture sealed
    • Make hole cutter responsible for hole filling
  • Air/Wind tightness, Acoustic, Thermal, Fire proof seals
    • No compromises (See Incompetency)

Insulation Application (Navigation)

  • Application of insulation
  • Applicator/Installer
  • Competency
  • Incompetency
  • Programme
  • Sequence
  • Inspection

Application of insulation

  • Correct size & quantity for application
    • Avoid any/excessive compression
  • Accurate sizing to fit
    • Airtight, no gaps, corners, abutment,
    • No compromises
  • Correct edge profile
    • Sealed abutted
    • T&G jointed
  • Offset lapped & 90 degree layers
    • minimise thermal bridging
  • Cross battens to minimise thermal bridging
  • Avoid metal fasteners that create thermal bridges
  • Avoid adhesives that make dismantling difficult or impossible
  • Approaches to securing avoiding fasteners and adhesive:
    • Compress, offer up, release, friction hold (medium density wood fiber)
    • Gravity into spaces (cellulose flake, exfoliated vermiculite)
    • Wet blown in (Hemp-lime, cellulose flake)
    • Dry blown in (cellulose flake)
    • Turbo blown in (cellulose flake)
    • Injected (


  • The building industry members are predominantly unregulated, apart form basic health and safety training for CSCS card, we can employ unskilled, build badly and that’s okay, Government refuses to regulate any further
  • But services and insulation now get special treatment:
    • Corgi replaced by GasSafe regulates gas installations because of risks of fire and explosion
    • Building Regulations Approved Documents BRAD Q regulates Electricity
    • MCS regulates the renewable energy sector for GreenDeal and ECO
    • PAS 2030 attempted to regulate insulation installation for GreenDeal and ECO
  • The skills training sector abhor multi-skilling at the risk of creating jacks of all trades
  • They will not train electricians and gas engineers to install insulation so that every time they open up a service duct or boxing to run their services that they insulate that service or duct so it does not have to be opened up by another to do the same
  • On this basis they may not be trained to seal holes cut through building elements, the integrity of which may be critical, at Grenfell they were critical and they were not sealed in at least one kitchen
  • Fire preventions and suppression installations are not regulated like services
    • Anybody with incompetence can install life critical systems
    • There is much evidence of lack of care by installers and supervisors
    • Post Grenfell this may change
    • If Government fails to enforce, then the industry must do, for its own credibility
  • Skills passports were seen as a means to demonstrate evidence of trade skills when seeking employment on sites
  • Skills are important but not essential for simple tasks like thermal insulation
  • Insulation sounds simple enough but this assumes understanding
  • But we have discovered this cannot be taken for granted
  • ‘Insulation Insulation Insulation’ means more insulation but it does not mean stuff more into smaller spaces
  • Knowledge with skills is fundamental
  • Skills and Experience is essential for more complex installations
  • Fiduciary rules dictate faster working, sometimes insufficient time to do the job properly
  • Contractors are always up against time programmes and sometimes enforce insufficient time for the job
  • Care is essential always
    • Installers often do have skills
    • But must be given time to care
    • Given insufficient time too often the installers eventually do not care
    • Supervisors must care when others cannot


  • Above all else appropriate levels competency of people and installations is essential
  • Manufacturer trained and approved installers are essential for competent complex installations
  • Some products are simple and can be suitable for Do it Yourself (DIY) Build It Yourself (BIY)
  • Self-builders may have no formal skills
    • but they have time to care, can and often do, a better job
    • than trained installers who are given insufficient time
  • Compromises are unacceptable when lives, human survival and profits are at stake


  • Incompetent acoustic performance irritates people, hinders work, reduces output, costs money, erodes profits
  • Incompetent thermal performance costs money and erodes profits forever after construction or puts health at risk
  • Incompetent vapour performance risks structural integrity with rot, mould and frost damage
  • Incompetent vapour performance risks health and life with mould, asthma, toxic mould and death
  • Incompetent fire performance permits flame spread and costs lives
  • Do not compromise


  • Bad programme and weather erode time available for the job on site
    • Lack of time denies time for installers to care
    • Can it be done offsite?


  • Details dictate sequence of work
    • Sequence needs to follow details
    • Details should acknowledge work sequence principle
  • Work sequences ideally follow basic principles
    • Work back from remote corners towards exit doors
      • To allow egress without walking over newly laid finishes
    • Work down from soffit to floor
      • To avoid risking damaging completed work below
    • Work from wet trades towards drier trades
      • To avoid dry materials absorbing moisture
    • Out of sequence working will probably spoil something already completed
    • Sequence is more important than programme, if you care about quality


  • Site Agents need to focus on competency of labour and snagging any incompetency in outputs
  • Bad programme and bad weather is not an excuse for an incompetent job on site

Finishes (Navigation)

  • Gypsum plaster, skim or parge coat
  • Cement plaster
  • Cement render
  • Lime render
  • Lime plaster
  • Clay plaster/finish
  • Hemp-lime render/plaster
  • Insulating Plasters
  • Insulated Render

Gypsum Plaster, skim or parge coat

  • Lightweight thermally insulating normally
  • Dense versions available
  • Moisture vapour resistant
  • Low absorbency
  • No moisture transport
  • Needs to be removed if insulating solid masonry walls internally
  • Avoid adding to historic fabric

Cement Plaster

  • Internally
  • High Thermal mass
  • Adds decrement delay
  • Closed to Moisture vapour permeability
  • Moisture resistant
  • Condensation risk high
  • Needs to be removed if insulating solid masonry walls internally
  • Never apply over historic fabric

Cement Render

  • Externally
  • Strong
  • Weather excluding
    • Drying shrinkage cracks lets it in
  • Closed to Moisture vapour permeability
  • Moisture resistant
  • Traps internal moisture
  • Never apply over historic fabric

Lime render

  • Externally
  • Soft and weak
  • Moves with soft weak background
  • Less likely to crack
  • Moisture vapour permeable, vapour open
  • Slow set, carbonation
  • Breathing
  • Anti septic, anti moulds
  • Alkali and potentially harmful in inexperienced hands
    • Not for DIY
  • Suitable for Historic Fabric

Lime plaster

  • Internally
  • Moisture vapour permeable, vapour open
  • Slow set, slow carbonation
  • Breathing
  • Moisture mass
  • Low condensation risk
  • Anti septic, anti mould
  • Alkali and potentially harmful
    • Not for DIY
  • Suitable for Historic Fabric

Clay plaster

  • Moisture vapour permeable
  • Dries but not set: easy to repair & DIY
  • Breathing
  • High Moisture mass
  • High density
  • High decrement
  • Low condensation risk
  • Absorbs electromagnetic radiation
  • Absorbs smells
  • Suitable for Historic Fabric
  • Not suitable externally unless sheltered with big overhangs

Hemp-lime render

Insulating Plasters

Insulated Render


Decoration (Navigation)

  • Oil based
  • Air tightness paint
  • Micro-porous paint
  • Emulsion
  • Lime wash
  • Clay based finish
  • Stains
  • Insulating Paint

Oil based

  • Skin forming
  • Traps moisture
  • Moisture resistant
  • Barrier to vapour
  • Condensation resistance needed
  • Mould resistance needed
  • Use on inside of external joinery as a vapour barrier

Air tightness paint

  • Air tight
    • Application making backgrounds airtight by simple brush or spray (not roller) application
    • g. Blockwork
    • Floor/wall connections
    • Wall/roof connections
    • Wall/wall connections
    • Window frame/wall connections
    • Penetrations (E.g. Services)
    • Can be: painted, plastered or lined
  • Vapour tight
    • Suitable for Vapour Closed Construction
    • Not suitable for historic fabric
    • g. Solid 9 inch brick walls
    • Especially if insulating internally
    • Sd = 18 m (0.5 mm coat)
    • The water vapour resistance of the product will vary, depending on the relative humidity difference across it.
    • A condensation risk analysis should be carried out prior to use of the product
      • Not a static analysis but a dynamic one across seasons
      • WUFI or Delphin
    • Combustibility:
      • EN 13501-1:207 Class E (Very High risk)
        • When applied to a calcium silicate board
      • Life expectancy: Life of building
      • BBA Certified for one product from Belgium,
        • Sprayed application outside of BBA scope and by approved applicator
      • Compatible with normal materials
        • Concrete (dense)
        • Calcium Silicate board?
        • Lightweight concrete block (other materials should be tested)
        • Red brick (extruded fired clay blocks) (other colours should be tested!)
        • Aluminium (windows, doors, not coated?)
        • Steel (Windows, doors, lintels, accessories: not galvanized? not coated?)
        • Wood (Windows, doors, joists, rafters, studs)
        • Plaster (Internal gypsum?)
        • EPDM membrane (DPM? DPC? Roofing membrane not internally)
        • PVC-U (windows doors)
        • Others should be tested

Micro-porous paints

  • Weather resistant
  • Vapour permeable vapour-open
  • Breathing
  • Use on outside of external joinery as a breather membrane allowing timber to dry outwards

Lime wash

  • Moisture vapour permeable
  • Anti-septic
  • Use inside or outside of vapour permeable construction
  • Whitewash
  • Also available with colour
  • Personal Protection Equipment (PPE) important

Clay based finish

  • Moisture vapour permeable
  • Breathing
  • High Moisture mass, but thin
  • High density, but thin
  • Decrement delay, but thin
  • Low condensation risk
  • Absorb radiation
  • Absorbs smells
  • Available with long life mineral colours

Insulating paints

  • MPs ambition!
  • Wishful thinking?
  • Its partly about nanotechnology
    • Is there a health risk?
  • Its partly about spray apertures
    • Can the glass bubbles survive the high-pressure nozzle?
  • Its also about aerogels, but very thin layer, offers very little insulation performance
  • Low condensation risk?
  • Low emissivity and bounces heat back
    • Warm to touch
  • No miracles here then

© GBE NGS ASWS Brian Murphy aka BrianSpecMan
28th November 2011 – 22nd April 2018

Insulation Properties Materials

Overheating issue Paper GBE Issue Paper Overheating: 1 Radiant V Conductive heat flows

© GBE NGS ASWS Brian Murphy aka BrianSpecMan
28th November 2011 – 20th October 2017

Insulation Properties Materials

This GBE Issue Paper

  • Whist writing and illustrating ‘Build-Light Insulate-Right Solar-Tight’ it became clear insulation needed explaining and expanding upon
  • One of GBE’s 1000 CPD files about Green Deal had addressed insulation in some detail, it was plundered and exploded in some considerable detail.
  • It too will be illustrated in due course
  • Its 24 pages so far it will no doubt keep growing over the next few months
  • These pages are being reproduced on GBE Website and will become subdivided into many pages in due course
  • Starting here:
  • if the page gets renamed it should always be found here:

GBE Issue Papers

  • Other Issue Papers running parallel to this paper and with occasional cross overs include:
    • Build-Light Insulate-Right Solar-Tight
      • GBE Issue Paper: Overheating (substantially complete, currently being illustrated)
    • External wall insulation (EWI) (complete)
    • Squashed Loft Insulation (complete)
    • Closing The Performance Gap (started)
    • Cladding fires in Tall Buildings (to be written, some items starting to appear here in readiness)

Abbreviations used in this paper

  • GBE = Green Building Encyclopaedia
  • GBS = Green Building Specification
  • CPD = Continuing Professional Development
  • LCA = Life Cycle Assessment
  • NGS = National Green Specification
  • ECD = Environmental Product Declaration
  • PEF = Product Environmental Footprinting
  • LowE = Low Emissivity
  • k value = Conductivity of individual materials of a building element
  • U value = Total Conductivity of all components of a building element
  • R value = Resistivity of individual components of a building element determined by conductivity and thickness
  • Total R value = Total Resistivity of all component of a building element

© GBE NGS ASWS Brian Murphy aka BrianSpecMan
24th October 2017


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