Published on October 13th, 2014 | by Henri0
Re-siding an old farmhouse
Q. My husband and I recently purchased an 1820 farmhouse and plan to put in new windows, plus new pre-primed cedar clapboards. We will use the Home Slicker with Typar. Our question concerns the following: The house is built with vertical planks, two to three inches thick, which are essentially slabs of wide trees. There are gaps between the planks, as they are irregular in shape. Do you suggest that we cover these planks with plywood before using the Home Slicker?
A. There is no need to use plywood over the planks unless the gaps are very large; anything up to an inch should not matter. The Typar is a windbreaker and the gaps will help the house breathe if there is no air barrier/vapor retarder on the inside of the exterior walls.
You haven’t mentioned insulation or the inside finish. Is there any insulation on the living space side of the planks? If not, and there is no way to do so from the inside, you may want to consider installing 2-inch thick rigid insulation over the planks followed by 5/8th-inch CDX plywood sheathing onto which the Typar/Home Slicker can be stapled. Even though clapboards should be nailed onto studs, since you will providing a rain screen behind the clapboards, they should be OK nailed to the plywood.by