A vapour barrier is a damp proofing product that is attached to a wood floor underlay and is intended to reduce the passage of moisture.
Vapour barrier suspended timber floor.
To answer your question introducing a vapour barrier to the underside of the floor joists would be a complete waste of time that is other than to assist in the air tightness of the building which is another bone of contention whereas introducing a vapour barrier over the top of the floor joists may well provide some long term benefits by reducing the amount of water vapour introduced to the timber.
Tyvek supro membranes are sturdy and durable.
They provide adequate support for the insulation and are recommended for use in suspended timber floor constructions.
What makes this stand out from the 3 in 1 blue underlayment is the added noise barrier to reduce foot fall noise.
Versatile application used within floor wall and roof constructions.
This helps to minimise underfloor condensation and hence the risk of mould or decay while improving the thermal efficiency of your floor and building.
It is important to state that vapour barriers are not damp proof membranes and shouldn t be considered as such.
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.
This 3 in 1 underlayment can be used under any laminate flooring to allow your floor to float and create a moisture barrier.
There should always be proper ventilation between the ground and the shed floor.
The membrane is supplied in single wound rolls not folded 2 0m x 50m.
Tyvek membranes are ideal for suspended timber floor construction.
Vapor 3 in 1 blue underlayment is the most budget friendly option of all vapor barrier underlayment.
Previously floor timbers had been prone to damp and rot thanks to their direct contact with the moist ground.
They are vapour open yet greatly reduce air flow when correctly installed.
Vapor barrier for wood shed floor you should only use a vapor barrier if you plan to heat or air condition your shed.
Vapor 3 in 1 underlayment silver 100 sq ft roll.