Drilled all the way through my foundation... is that bad?

While drilling for anchors to secure a non-load-bearing wall, I drilled all the way through my foundation. I was surprised to learn it's only 4" thick.

My main question is, is drilling all the way through and filling with anchors going to cause any problems? Do I need to seal it in any way? I don't have any moisture problems in my basement. I'm in Seattle, WA.

Second, is a 4" foundation surprisingly shallow? House was built early 1950's.

 

Welcome to the forums.

The blocks used for foundations are 8" but have hollows in them. You probably drilled into a hollow. You're fasteners will work fine and no structural problems.

 

Is that true for a slab concrete foundation? I was told I had slab with footings.

 

Are you talking about a poured concrete foundation ?

If it were only 4" thick you'd be in dirt. Stick something long into the hole.... are you hitting dirt ?

 

Unfortunately all the holes are filled at his point. There was still powder in the hole from the drilling. It didn't fall through and empty but drilling suddenly became exceptionally easy.

 

You were drilling in the floor, right? No worries.

 

My mistake

For some reason I thought you were drilling thru the walls.

 

Not sure how to attach a picture from my phone...

 

This is in the floor. Sorry the picture is so diagonal, but those anchors are going down into the floor. (One was a screwup where we didn't drill deep enough and broke off the bolt and messed up the threads)

 

Not sure if replying to people's comments was the right thing to do so I'll make a non-reply comment. To summarize, I believe I have a 4" slab concrete foundation for my basement floor which is what I was drilling into/through.

Well, I have a couple more to drill, so I guess I'll check if I see dirt or whatever.

 

You are fastening this "wall" over laminate flooring. This will cause buckling problems with the flooring. If this is non load bearing, why the large hardware? All you are seeking is lateral control, and a powder actuated pin will do the same thing and not go through your concrete. You are opening holes up in the bottom of your "boat" that are unnecessary.

 

No I just made a really nice square cut in the flooring. If you look closely you can see the gap between the bottom plate and the flooring, especially in the very top right of the picture.

 

Unfortunately, you did make a really square cut. Laminate needs room to breathe. There should be a minimum 1/4" gap and preferably more around your new wall. You will have floor issues if you do not give it room to expand and contract. Laminate is also not rated for below grade installations.

 

I'm not a carpenter so I can't comment on the installation but when I need to fasten a 2x4 to cement I'll either shoot it in with a powder actuated gun like Larry mentioned or use Tapcons.

With a Tapcon you drill a hole thru the wood into the masonry using the long Tapcon drill bit and then drive the screw in. Makes for a fairly strong and quick installation.

A little video illustrating their use....youtube/watch/tapcon use

 

Well, the laminate was there when I bought the house. I can easily cut out a gap around the wood, and I'll go ahead and do that before drywall.

 

It is possible to have a concrete foundation consisting of a slab that is poured after a strip footing and a poured wall or a concrete block wall is built on the strip footing to make a structural walls. It is EXTREMELY RARE to see wall and footing poured as one unit and be structurally sound. The strip footing is poured to provide a stable area to build the walls (block or poured concrete) on. - You need a solid base to set and align forms or lay block on. If you have a basement, the basement floor (usually 4") is poured later on top of the strip footing and it helps to restrain or prevent the wall from sliding if the vertical reinforcement is not adequate (belt and suspenders concept).

For block foundation walls, very often, a special block for the top course is used to finish off the wall that has a solid top (3/4" to 2" thick) to work off of for the above grade walls. Depending on where you are it has many names - "FHA" (for obvious code requirements/reasons), "filled top" or"semi-solid". This can explain the ease of drilling deeper when you get through the solid portion.

Most of the common attachments, if spaced properly are adequate to resist the small lateral forces from a wood framed structure above grade.

Dick