I recently purchased a home, built in 1990. The previous owner filled the ventilation openings in the first row of brick above the blocks. He used a yellowish orange material that expands when it cures (silicon ?). This was done to keep the bugs out of the house. I have started to remove this material with a 1/4 inch bit in an electric drill. I am getting in bout 4.5" to 4.75". How far should I be going in? Can I do any harm if I go in too far?
Answer:
You're doing the right thing but I think I'd keep the vacuum cleaner going all the time I'm drilling to ensure that as little of the stuffing stays in the cavity as possible. You are certainly going far enough and I don't think you should go farther because then you're into either the sill plate or exterior sheathing and surely bees, etc. will find their way to the openings into stud cavities sooner or later.
