I need to seal windows on a log home. The builder failed to properly seal the window flanges to the buck faces, or to flash the bucks first. However, I’ve worked to seal the outside flanges with caulk and an adhesive-back durable membrane. This has been pretty successful, except for a couple of windows for which the window opening was too big and great amounts of caulk were the builder’s answer.
From the inside I’ve removed the caulk, fiberglass insulation and occasional foam sill sealer to expose the window flange. I’m planning on laying a bead of low-expansion foam along the flange, where the tube can reach, and then filling the remainder with sill sealer. In all other areas (where I can’t see the flange or reach the flange) I was planning on using foam sill sealer, rather than fiber insulation. My thinking is that the foam will help seal out any moisture, and the sill sealer will be less likely to retain any moisture that would tend to rot the wood.
Does this make sense? Are there better options? thanks for any feedback.