Vapour Barrier Suspended Timber Floor Construction Detail

Vcls or vapour barriers will only reduce the vapour movement to an acceptable level.

Vapour barrier suspended timber floor construction detail.

Moisture management for suspended timber floor construction many suspended timber floor constructions have discontinuous insulation between the joists. It is important to remember that no material is completely vapour proof so the term barrier can be slightly misleading. The ground should have a layer of concrete poured across and there should be a ventilated gap of at least 150mm between the underside of the timbers and the concrete to prevent moisture gathering and affecting the condition of the joists. However vapour barrier specification and details together with those for dpc and dpm are only mentioned in relation to the two generic floor construction types of suspended timber floors and concrete slab on ground in e2 as1 section 10 0 floors.

That leaves an opening to improve moisture management and airtightness by fitting a tyvek membrane and carefully sealing the gaps and joints. Some people and organisations will refer to the material that controls vapour movement as a vcl and some will call it a vapour barrier. A damp proof membrane or dpm is a waterproof barrier that s introduced between your sub floor and your wood floor. This barrier is intended to stop moisture passing from one to the other.

A vapour control layer with a low sd value that allows limited vapour transmission especially recommended on mineral wool wood fibre cellulose fibre and other breathable insulation materials. Effectively a thick plastic sheet a damp proof membrane dpm is used to create a barrier between a concrete or screed subfloor and a wood floor. At the turn of the 18th century when construction techniques moved from boarded floors installed directly on the ground to suspended timber floors over a ventilated chamber the innovation solved a significant problem. Suspended timber floors required under clause h1 energy efficiency.

Previously floor timbers had been prone to damp and rot thanks to their direct contact with the moist ground. Hi i did just like to check my plan for installing some insulation in a timber joisted suspended wooden floor in a 1900 ish terraced house. Once the wedges are removed they are replaced with strips of cork or polyethylene foam to act as a compressible filler and to help prevent cold bridging. Once the timber floor boards have been laid temporary wedges should be inserted between the walls and the floor to maintain tight joints until the adhesive has set.