2 part question here.

My house has these vents in the foundation:
vented brick

There are several of these around the house. They're about 18"x10". I want to block them off so mice and small animals can't get inside. My plan was to use 1/4" hardware mesh, cut it to the right dimensions then use Tapcon bolts (I have a box of 1/4"x 1 3/4") to secure them to the concrete.

  1. Does this seem like a good idea? Or is there a better or easier solution?

If it's a solid plan, I also had questions about the Tapcons:

  1. (a) Can I use a normal hammer drill for this or should I buy an SDS? With 4 vents and 4 holes to drill per vent, I'd be looking at making 16 holes in the concrete.

  2. (b) Once the hole is drilled, can I use an impact driver to drive the Tapcon?

  • Presumably you have a crawl space; the vents are there to provide air circulation to prevent moisture from collecting. It depends on your climate and the nature of the crawl space. I had one in northern IL that was bare ground . I had various moisture problems . I put down plastic sheet with some gravel and added more venting. Sep 8, 2021 at 0:42
  • Might want to add finer screening also.
    – crip659
    Sep 8, 2021 at 1:04
  • @blacksmith37 yes, there is a crawl space. I'm gonna put mesh over it so air will still be able to circulate.
    – Dan
    Sep 8, 2021 at 2:27
  • I agree with what you've proposed. But I'm surprised that there wasn't some sort of screening over those holes in the first place.
    – SteveSh
    Sep 8, 2021 at 14:58
  • @SteveSh, there is but not attached by any means. It's just sitting there and by the looks of it, animals have been moving it aside.
    – Dan
    Sep 8, 2021 at 17:07

4 Answers 4


Here's a different apprach, but may be more work.

Cut a rectangle of your hardware screen approximately 1/2" longer and wider (1/4" on each side) than your opening. Slit the 4 corners on a diagonal 1/4"-1/2". This allows you to fold the edges without buckling the screen. Then, force the piece of screen into each opening. The edges should spring back and hold the screen in place without any hardware.

Another advantage of this approach is that the screen will not be visible from the outside.


That's a solid plan. The only thing slightly easier than manhandling hardware mesh would be to purchase pre-framed ones. Obviously, that's way more expensive.

Tapcon-wise, a small hammer drill will work hard with the 3/16 drill bit, but just take your time. (Pull the bit out regularly as you drill.) A rotary hammer is nice for bigger holes, but not necessary for this.

Yes, use an impact driver. If the tapcons have a slot/hex configuration, use a hex driver. If the tapcon seems to jam as you're driving it, just reverse and try again. If it keeps jamming, drill the hole out a couple more times.

Don't forget big washers on the screws.

  • 2
    Yeah I made sure to get the bolt-style tapcons, dealing with a lot of stripped screws from the previous homeowner is making me hate phillips.
    – Dan
    Sep 8, 2021 at 2:31
  • 1
    If the Tapcon jams in the hole, continued efforts to drive it will likely result in a snapped screw. Ask how I know. Don't "try again" until you've changed the situation.
    – FreeMan
    Sep 8, 2021 at 13:14
  • Agree with both of the above comments, except to note that it's way harder to snap the 1/4" screws. (And for what it's worth, I've totally given up on the skinny countersunk philips ones, both because of snapping and stripping.) Sep 8, 2021 at 14:09
  • 1
    I used 2-1/2 or 3" screws that I didn't think were all that skinny. When they wouldn't drive any further with the impact driver, I switched to a shorty socket handle and that was more than enough extra torque (without even having to grunt) to snap them right off. :( And yes, I've abandoned Phillips head screws for just about everything but cabinet hardware (hinges & handles still seem to insist on shipping with them and Torx just doesn't look quite right on an exposed hinge...)
    – FreeMan
    Sep 8, 2021 at 17:16

Leave an escape route.

Trapping animals in a space is no good. They try hard to get out and chew everything. Then they die and stink. Ask how I know!

Leave one of the holes open so the animals that live under there can leave. Put a Havahart trap in front of their route out and you can catch and either kill or relocate them as they leave. Then when no more are coming out you seal the last hole.

  • Yeah that was the plan. Someone mentioned I could throw some sort of smoke bomb to get them to leave quickly. Is that a good idea?
    – Dan
    Sep 8, 2021 at 2:28
  • Smoke rises, guess where the smoke will go.
    – crip659
    Sep 8, 2021 at 9:58
  • I have heard of using dry ice instead of smoke to flush out critters. Many advantages: no fire, heavier than air, no potential damage to structure. Cheap, for sale at the grocery store.. I would put the nuggets thru the holes then blow them in deep with a leafblower. The only question is whether it works.
    – Willk
    Sep 8, 2021 at 13:44

As small a hole as you're going to need, there's no need for even a hammer drill. A masonry bit in a regular drill and some patience should work just fine. No doubt a hammer drill or a rotary hammer (yes, they're different) will make it easier, but if you don't have one, all is not lost.

Also, If you're driving the Tapcon and it stops short of full insertion, STOP driving it or you will snap it in the hole!!! Back it out and blow out the hole. As a matter of fact, I'd strongly recommend blowing out the holes before you even start driving the screws in. Use air from your compressor (every DIYer has one, right?) or just a small can of canned air. You'll note that I learned this the hard way and that the last paragraph of the accepted answer is where I picked up the tip.

  • 1
    Cool, yeah I've read about the importance of doing that as well as drilling deep enough beforehand.
    – Dan
    Sep 8, 2021 at 17:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.