Q - Last summer during my termite inspection, the technician said that one of the vents in my crawl space was blocked and suggested I remove a cinder block from my foundation so that the vent could circulate the air better. That portion of my crawl space was damper than the rest. My house is brick, and the vent is mostly blocked.

How do you suggest I remove the block? I have worked on it a couple of hours already with a chisel working on the mortar, but things keep binding and I have bent at least one chisel. I'm now thinking about drilling the mortar out with a masonry bit.

I am open to any suggestions.

John in Dacula

A - Here's what I would suggest - don't listen to your bug guy giving crawlspace advice.

The blocked vent is actually a good thing, in fact they all should be blocked or closed, in fact in fact it is now against building code to even install vents in crawlspaces period.

It has been shown that vents in crawls are a leading cause of too much humidity in the house, and it makes sense if you think about it. What would keep the moist summer air from coming in through the vents? What forces the air out of the vents?


At the very least do this:

Close the vents. Get some 6 mil (10 mil is better) plastic at your local big box hardware store and cover your entire crawlspace floor with it (wall to wall, edge to edge). Put a heavy rock or a cinder block or your wife's meatloaf every 6-8 ft to keep it in place. That will cut down on the moisture in the crawl (and in your house).

While you are at it get some R13 or 19 batt insulation and put it in the floor joists above your crawl (paper side facing up towards your house). Now you have more insulation and two vapor barriers in your crawl. Minimum cost, minimum effort, nice results.

For the best results, have your entire crawlspace encapsulated. That will seal it up and keep that damp air from infiltrating your house, and yes, you can still use your crawlspace to store junk.

Re-mortar the brick (you might find a mortar patch kit at the store as well)

Tell the bug man to focus on killing bugs.

Take the rest of the day off.

Thanks again and good luck.