Drilling holes in basement concrete walls

[SBH]

I'm currently in the process of remodeling our basement. It's a finished basement but with paneling and older moldings all around. The wife and I just painted over the paneling and installed new molding which is coming out quite nice. One thing I've discovered while doing this project is the method the previous owner used to put up the walls. There are furring strips, with foam insulated boards, then drywall and paneling on top of that. Some places on the wall lead me to believe everything is glued and not drilled in. I am assuming the furring strips are glued to the wall, but cannot accurately conclude without tearing it up and that's not going to happen right now. The wife wants some shelves on this wall and I do not feel safe about fastening them to the paneling/drywall only. Therefore, I was thinking of drilling into the concrete wall behind, then using Tapcon screws to put the shelves up. The brackets for the shelves have many holes (8 per shelf x 3 shelves). Will there be any consequences of drilling many holes into the concrete? I feel uneasy about doing that also, but I'd thought I'd ask first.

Thank you for the help.

[ransley]

It should work

[Rodger]

Don't worry about it - you don't need to go that far into the foundation and the number of holes is trivial...

- Rodger

[ransley]

Of course Rodger is full of it, 8 holes per shelf says it all, but with a Roger you will be sued for everything even non existant Radon and Mold

[Malcolm Hoar]

No worries on the structural strength. You'd have to drill a ton of very large and deep holes to weaken those walls. You'd install shelves by screwing into (relatively) flimsey studs. A few Tapcon's sure ain't gonna kill your concrete.

Just worry about any pipes or cables that might have been channeled in the concrete or run between the drywall/paneling and the concrete. Also check that tightening the screws isn't going to compress the insulation and deflect the drywall/panels.

And, yes, I'd be concerned about fastening shelves to the drywall alone. That's okay for small pictures and the like. But shelves should be fastened to something structurally solid like studs or concrete, IMO.

[Dan]

Do you meet code for auxiliary exit from basement?

[dadiOH]

The consensus says drill away. However, it might be simpler to build a free standing shelf case. Simple vertical cleats along the two vertical ends and a horizontal one across the top with maybe two molly bolts in each into the drywall would keep it standing very well. Actually, you only really need the top cleat.

[Robert Barr]

first.

True, it won't harm the wall itself. However, he'll be using Tapcons, which grab by exerting radial force. Anchor manufacturers recommend a distance of at least 10 anchor diameters between hole centers to prevent cracks from forming between the anchor bores. (This is specified in extreme detail for Tapcons here:

If you have a dense pattern of fastener holes, you're better off anchoring some backup lumber and drilling the dense pattern into the wood.

You'd

[Malcolm Hoar]

That's true but I have a hard time imagining anything in a normal residence that would normally make it necessary.

It's not typically worth it with shelves -- you'd have to drill as many holes in the concrete to fasten the backup lumber as you would if you fastened the shelves directly to the concrete. After all, a shelf is just a long piece of lumber anyway ;-)

And in a really heavy duty situation, one would likely want to use metal versus lumber as the intermediate medium.

[Chris Lewis]

According to SBH :

I would assume that these are simple L utility brackets? These usually have 6 holes (three for the wall and three for the shelf).

Must be enormous shelves with lots of load to need 8 brackets apiece!

Have you done checking to see whether your really do need that many brackets per shelf?

At 3 tapcons per bracket, that's a lot of holes (around 75). Seems way overkill. Unlikely to be a problem for the concrete unless the holes are really close together.

When installing shelving like this, I tend to consider using track&bracket type shelf supports. Has the advantage of being able to adjust shelf height. You won't need nearly as many tapcons. You could cut slots in the shelves to fit over the brackets.

In a utility area, I'd consider using 2x3's instead of metal tracks, and use normal wood screws to fasten the brackets. You may be able to "dress" (eg: sand/paint) the wood so it's more suitable for a less-utilitarian look.

For 3 shelves, you could probably get away with 4 or 5 tapcons (of the larger sizes I think) per track, unless the loading is unusually high. You could even use lag+anchors if the track can be modified to suit.

[DerbyDad03]

Based on my experience with Tapcons (or ProCons) my only concern with using them is that you typically have one chance to get them right.

If the hole is too sloppy the screws won't hold.

If the holes aren't exactly in the right place, you can't easily correct it. Hit a rock or rebar and you'd have to relocate that bracket and possibly anything associated with that bracket.

If the screw doesn't go in all the way the first time, rarely, if ever, can you restart them without stripping or snapping them.

If you snap a screw, that hole is done.

If you back a screw out, typically that hole canot be reused.

I don't like to use TapCons (or ProCons) when precision is required. In this case I'd consider attaching cleats to the wall, where exact location of the fastener won't be as critical, and then attaching the shelfs to the cleats. Easier to adjust/readjust the brackets later.