Wood is a renewable, eco-friendly resource that is growing in popularity as a building material. When building with wood, it is important to understand how wood reacts to ambient environmental conditions in order to ensure its longevity.
Wood will expand in humid conditions and shrink in dry conditions. It is essential that you allow it the space to do so or you will experience buckling and connection issues. When installing floor, roof or wall sheathing panels, ensure that there is a 1/8” gap between panelsto allow enough space for expansion and contraction. It’s not just a best practice but a requirement for virtually all panel producers.
Select connectors that are detailed for wood shrinkage to avoid splitting or loose fasteners. Swelling of wood can cause connectors to bend if there is no room. Find details for connection design from the APA (the Engineered Wood Association) here.
When selecting exterior connectors, ensure they can drain moisture so that it isn’t trapped where it can cause rotting.
According to the APA: “Also, avoid leaving wood in direct contact with concrete, masonry or grout, which are porous and wick moisture. One solution is to leave 1/2-inch air gap between wood and these materials.” When wood is touching damp materials, it can cause rotting, so leave a gap.