GBE 1960 Timber Frame Retrofit Q+A

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GBE 1960 Timber Frame Retrofit Q+A
About:

Hi I am a project management student and a retrofitter of houses

I have just signed up to the discounted Student membership of GBE

GBE Membership (Sign-Up) G#23472

Thank you for signing up, it is much appreciated, every little helps GBE to continue to be developed.

As a college project we have to propose a complete retrofit of a 1960’s timber frame house to bring it up to current standards and proposed a new build of the same floor plan to new build current standards.

Q1 What help can you give me?

O1 You are asking an unusual time in July for a college project.

R1 I have had to take time off for Neck Surgery and a long recovery time and now I am trying to get back up to speed and considering when to plan to submit, now within a few days or defer until next year.

Survey Existing

Okay lets go back to basics: Understand what you have got before anything else.

Surveys Tests Analysis (CPD Lecture) G#389 N#390
GBE Refurbishment Decent Homes (Checklist) G#1253 N#1252
GBE Decent Homes (Checklist) G#1571 N#1507
GBE Refurbishment Decent Homes Checklist (CPD) G#644 N#666

Less sophistication:

Timber in framing, windows and doors and stairs and furniture
Masonry if any, cavity not solid wall
Ceramics: sanitary ware and tiles
Metals in accessories and services
Less plastics, some in services
Unlikely to have vapour barriers?
Probably has breather membranes and damp proof membranes and course
Insulation unlikely or 2” ≈ 50 mm glass or stone mineral fibre

Timber frame:

The timber frame, floor and the roof is likely to be hand cut on site,
Spacing at 2’ ≈ 600 mm centres or even 18” ≈ 450 mm centres
Timber studs may be as small as 4×2” ≈ 100×50 mm
Roof timbers and ceiling joists may be as small as 3×2” ≈ 75×50 mm or 4×2” ≈ 100×50 mm
Timber suspended floor: may be ≈ 8×2” 200 x 50
(21) Timber Frame (Lecture) G#2117 N#219

Sheathing board:

There may be a sheathing board of soft-board or wood fibre board on the outside (contributing a little to the thermal insulation)

Outer cladding:

May be timber weatherboarding
May be tile hanging
May be brickwork outer leaf

Widows and doors:

May be unsophisticated EJMA profiled softwood frames
Probably single glazing

Internal lining and ceiling

May be soft-board lining and plaster skim
May be wattle and daub plastering
Might even be plasterboard with or without skim

Finishes:

If there is any Artex coated surfaces (not by the constructor, usually by the occupant) take care to have an asbestos survey carried out

Services:

All electrics should be updated by rewiring to current IEEE standard and consider the accessories for reuse, resale and replacement
All plumbing should be checked for lead pipes which need to be replaced with copper or plastic
Asbestos cement water tanks
- Need not be replaced
- But if they are damaged then get them removed by licensed Asbestos specialists
- Replace with plastics
Boiler efficiency will be very poor by today’s standards
Heating distribution may be within an un-insulated concrete floor or cement-based screed dissipating-heat where it may not be well utilized.

Thermal insulation:

1960’s almost no requirements for Insulation,
50 mm in the ceiling?
Probably none in the timber frame, if you are lucky, 50 mm in the frame?
Framing voids offer little insulating value but they are space of eddie currents and thermal bypass to occur
Some soft board sheathing board offers a little thermal insulation

Thermal bridges:

In the absence of insulation thermal bridges are potentially more insulating than air, but of little area

Airtightness:

Likely to be very poor, well in excess of 10
8 = Noisy wind whistling through gaps, papers disturbed on tables

Proposals: Performance

Approach:

Whole house plan, accommodating any phasing of the work
PAS 2035/2030: 2019 Design and Installation for Retrofit
GBE Retrofit PAS 2035 (CPD) G#21613

Energy Standards

GBE Calculator Whole Building Uvalue to In Use Carbon A06 XLS (Shop) G#11095
GBE Calculator Whole Building Uvalue to In Use Carbon A05 XLSX (Shop) G#11009
Building Regulations Approved Document L1B targets:
- Existing Domestic Building Refurbishment
- U value: 0.18 W/m2.K (threshold 0.35)
- U value: 2.0 W/m2.K Glazing (new build) (no data obtained)
- Airtightness: 10 or no requirement (no data obtained)
- Inadequate for UK European Global carbon Targets
Scottish Technical standards 6.2 (2010)
- Existing Domestic Building Refurbishment
- U value: 0.13 W/m2.K
- U value: 0.8 W/m2.K Glazing (new build) (no data obtained)
- Airtightness: 10 or no requirement (no data obtained)
- Inadequate for UK European Global carbon Targets
Northern Ireland: No data collected so far
AECB Carbon Lite (Passivhaus for UK Climate and Energy mix)
- Existing Domestic Building Refurbishment
- U value: 0.15 W/m2.K
- U value: 0.95 W/m2.K Glazing (new build) (no data obtained)
- Airtightness of 10 or no requirement?
- Adequate for UK European Global carbon Targets
Passivhaus EnerPHit
- Existing Domestic Building Refurbishment
- U value: 0.15 elements
- U value: 0.8 W/m2.K Glazing
- Airtightness: 1
- Adequate for UK European Global carbon Targets

Other issues:

Moisture management:

Consider using a vapour open construction and breathing insulation materials
No vapour barriers but intelligent air and wind tightness layers

Solar radiation and solar gains:

Existing timber frame (without brick outer leaf) will be subject to solar radiation
Solar gains through the opaque fabric will potentially overheat the building
Insulation needs to have decrement delay characteristic

Acoustic performance:

Existing timber frame (without brick outer leaf) will be subject to acoustic penetration

Consider insulation:

between, outside or inside the framing
Cellulose flake, cork granules between the framing,
Dense wood fibre, cork board, cellular glass inside or outside framing

Proposals:

Accessing the wall and roof framing:

Take special care to not damage any cladding or linings to allow salvage and reuse of existing materials
Wattle and daub: save and reuse oak wattle, recycle lime plaster
Plasterboard will be more difficult to salvage
To allow for adding of insulation to stud zones

Framing:

Due to existing sections being too small to achieve useful U values
Cross batten inside outside or both to create a deeper stud zone
Battens at right angles to the studs to minimise thermal bridging to cross overs
Add breathing insulation in layers between studs and then between battens
Suspending insulation in floor joist zone
- Insumate 600 Tray G#1762 N#1658

Claddings

Reinstall breathing sheathing board or install dense wood fibre board to outside
Install breathing wind tightness layer outside
Re-fix salvaged cladding to wall and roof to outside with battens to form ventilation void

Linings:

Install breathing sheathing board or install dense wood fibre board to inside
Install breathing airtightness layer inside
Re-fix salvaged linings to inside with battens to form services zone void
Install services in batten zone, insulate batten zone between services and battens
Reinstall salvaged linings or install new linings

Windows

GBE Database (Navigation) G#486 N#498

Passivhaus Windows and Doors

Cold water tanks and header tank in loft

Insulate tanks
Insulate perimeter of tank platform to direct heat from house up to tanks
Attic cistern thermal insulation enclosure G#1041 N#1058

Raised access walkway

Install walkways from access hatch to services installations
Add storage areas near hatch for all domestic storage
LoftZone StoreFloor CPD Handout (Shop Free) G#16383
LoftZone StoreFloor CPD (Shop) G#16381
Squashed Loft Insulation (Issue Paper) G#13919
GBE K43 Raised Storage Access Systems (Checklist) G#13934

Materials and Suppliers

Suppliers (Navigation) G#610 N#631

Other’s Training