Building Granny Flat. Step 4: Sealing the bottom boards

The fourth step in building YZY Kit Homes granny flats is to seal the bottom boards. This Step is to stop the moisture coming up from flashing.

That is another one of the most important steps before you get too far involved. So grab the bottom boards, locate which end halls are going for electrical and hold down bolts. Brush a preservative on underside just to stop any moisture penetration that comes from the top of flashing installed around the perimeter of the building. It is also a good idea to seal the end grains to stop the checking and cracking, the first board is the most important to put a sealer on.

Expert’s tip: Waterproof the flooring of the sub-floor with the flashing around the perimeter. Apply an even coating of CN (Copper Naphthenate) timber protective Emulsion to the lower wall-boards. Follow the timber preservation chemicals manufacturer’s instructions. Please note, it must be applied sparingly as it might show through any internal or external paints.

The next step is to fix the first layer of wall-boards to the sub-floor. All granny flat building steps can be found on Builders Guide page.