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Platform Floors Levelling Screeds Q+A

Platform Floors Levelling Screeds Q+A
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Q1 Could you verify that we have levelling screed specified for the office floors.

When walking the (partial demolition/alteration) site it is visually obvious that we need one.

A1 If the offices are to get a raised access floor then the slab floor may not need ‘levelling’

The props and the adhesive/shims/fixings provide the levelling function (not smoothing function).
‘Levelling screeds’ may be thick cement/lime/aggregate screed or fine concrete or very thick wet concrete overslab
This would not be applicable in the office spaces.
But ‘Levelling screed’ can also be very thin epoxy resinous material laid on new or existing not-smooth or not-level surfaces
Due to their costs the later tend to follow the shape of the existing surface, smoothing the roughness but not levelling the surface
The later do not normally flood the low parts and bring everything level.
They are expensive so are not normally laid in a thickness that could be called levelling
But if the floors are too rough to drag cables with sheathing, that may get ripped off, then Smoothing may be useful.
Who will decide the extent? Type? Thickness?
Take care not to reduce the servicing zone by ‘levelling’
Smoothing (epoxy/resin) is not a cheap material or product and not normally good for BREEAM (VOC and material rating)
Levelling is a labour intensive process, vibrating and tamping of concrete, levelling board of screed
Smoothing is also a labour intensive process: troweling, Power troweling, Power grinding of concrete or screed
Self-smoothing is a property of liquid applied epoxy/resin thin floorings but some need the help of a hand trowel.
Levelling is not normally poring loads of resin until floor is flooded and level, at great cost.
NB: Self-levelling is only available with liquid applied gypsum/anhydrite screeds or water.