I've recently moved my woodworking space into our house's basement garage. I want to mount some french cleats on the blockwall. Far as I can tell, the walls make up the foundation and are load bearing The I-beam seems to rest on them.

I don't anticipate drilling any large holes (>=2in). But before making holes I can't fix, I figure it'd be a good idea to make sure I'm not doing any damage or introducing any structural issues.

I'm unfamiliar with drilling into concrete. Are there any important details to take into consideration before making holes? If I make a mistake or two, any way to fill the holes and possibly restore some the weakness I've introduced to the wall? For example, I've seen Quikrete Mortar Repair

My question isn't necessarily how to go about drilling into concrete, there's a lot of material on that that's pretty easy to find. It's more on when it might be a good / bad idea to do so.

If anyone could answer one of the following, I'd really appreciate it

  1. What should I consider with regard to structural integrity when drilling a 1/4in-1/2in hole in concrete?
  2. For a 1/4in-1/2in hole, would drilling into the mortar or block be better?
  3. Can I repair any holes with and restore any meaningful amount of strength to the wall?

I feel like I might be overthinking all of this for a couple small holes, but I'd appreciate any info or resources you could provide to me.


  • 1
    Unless you be putting TNT into the holes you have nothing to worry about, except drilling the holes.
    – crip659
    Commented May 13, 2022 at 22:17
  • 1
    Are these large blocks (like, 16x8) or smaller bricks? Do you plan to have to remove the cabinetry and repair it at some point? (Repairs will only be cosmetic -- not structural.) Commented May 13, 2022 at 23:45

1 Answer 1


There are usually no concerns in drilling into blocks or concrete, unless drilling though to the outside underground and making a path for water to leak in.

Mortar is the easiest to drill into, but the weakest for holding power.

Blocks and concrete have the better holding power. Blocks will probably be better to use toggle anchor bolts. By blocks mean the ones with empty spaces inside, not solid ones.

The only concern with drilling holes in cement type foundations is if you make a whole line top to bottom/side to side of many holes right though. Most people are quite happy to just finish a few to hold something.

Your Answer

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

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