Thread: Gun safes, concrete, and AnkaScrews

One of the risks of drilling into the concrete is hitting a spot where for whatever reason the slab is thinner than it is meant to be and you punch right through. I had that happen when fitting the anchor bolt for the bottom stud of one of the partition walls I put in my basement - was supposed to be a 100mm+ slab but drilled in 70mm thereabouts for an anchor bolt with 65mm penetration needed and popped through and found clay as I was getting to the marked depth. Hmmm...

What you can do is use a high quality permanent and fully underwater rated sealant (not roof and gutter silicon) and plug the hole with that until it's full, then fit the anchor bolt. It's not the "approved" repair for a breach in the damp proof course, but from my experience of it and if you use the right product with a cleaned up hole to remove any dust etc, it is as effective as not holing through and the DPC wasn't damaged.

For the anchor bolts, the Ankascrews would work I think as they have a similar rating to the wedge anchors, but I don't see any reason not to use anchors. You can drill the hole deeper than needed, and at removing time pull the wedge bolt up, cut it off, and punch it deep down as someone else suggested. If you get the type where the wedge sleeve is one piece and not two (some makers have a wedge section that is the same for all their sizes of anchors and then a different length sleeve for the various lengths of bolt to take up the extra space), you can sometimes punch the bolt down and lift the wedge sleeve out of the hole and then recover the bolt with a magnet as well.