Sill Plate Treatment – GreenBuildingAdvisor

Hi,

In my basement I have double 2×6 sill plates sitting on a CMU foundation. There is no gasket between the CMU and sill plates. After a major rain, I notice the sill plates can be damp. The house was built in 1964, and the sill plates currently have no rot. I cannot tell if the sills were pressure treated. 

Out of caution, I’d like to preventatively treat them to prevent future rot, and am confused by the various options I’ve seen online – which are listed below. Any advice or thoughts on what the best option is to prevent future rot (besides just installing a gasket) would be much appreciated! Note: I only have access from inside the basement, the exterior is behind brick veneer. 

1. Borate rods (if recommended, what brand and where do you buy them from?)

2. Spray bora-care w/ mold care

3. Copper coat.