I want to attach fiber cement siding planks to furring strips over concrete wall. My understanding is that I need some moisture barrier to prevent water from getting to the wood. So can I staple 6mil plastic for that purpose? The surface I am covering is very small – around 30sqf.
Use plastic as moisture barrier under fiber cement siding
moisturesidingvapor-barrier
Related Topic
- Electrical – Installing a exterior light in existing vinyl siding
- Basement – Plywood over rigid foam over concrete: will I have moisture issues
- How to deal with the giant foundation overhang when using ridged foam and a rain screen on an exterior wall
- What sort of vapor barrier should I install when residing an old wood-framed building
- How to prepare a log home for vinyl siding
- Put Hardie Board siding directly over old stucco
- How to protect this foundation sill from elements, rodents
Best Answer
The moisture barrier would generally go between the furring strips and the concrete and would be attached to the wall simply by attaching the furring strips to the concrete. If you wanted to really seal the area you could run a bead of adhesive sealant between the moisture barrier and the wood.
6mil plastic is a "vapor" barrier, not a "moisture" barrier. The difference is that a moisture barrier allows air to permeate it but prevents liquid water from going through. A vapor barrier prevents water AND air being transmitted through it. Moisture barrier is used between porous materials like concrete and wood to allow the various materials to acclimate to changing temperature and humidity without exchanging liquid water (the concrete will absorb a lot of liquid water from the ground, and then pass it into the wood which is a sponge for water, which will cause the wood to rot). If vapor barrier is used, moisture will be trapped on either side of the barrier, which can cause puddles of condensation on the moister and/or warmer side of the barrier.
So, to answer your question, you should probably use a product like Tyvek or TyPar, or an older material like roofing felt, between the furring strips and the concrete. For an installation like this, you can just cut strips of the barrier to prevent direct contact between the materials, and then simply place them behind the furring strips as you attach the strips to the wall.