Thread: Drilling holes into soft concrete footing

You will never drill a hole with a normal drill bit.

Let the footing cure for a couple of days then drill as per normal with a hammer bit. It won't affect the concrete or weaken it

The biggest problem in drilling green concrete is that you probably have an 80 to 90 % chance of hitting blue metal in the concrete and this will make the the drill bit run off because the cement not being cured you will have a hole bigger than what is required to get the maximum strength for your dynabolt.

There is more chance of doing more permanant damage to your footings.

It takes 21 days for concrete to cure properly.

Wow, only 80-90% chance. Seems more like 115% of hitting the blue metal and only slightly lower for getting the reo mesh.

I asked a question a few weeks ago about puting the dynabolts straight into the the wet cement and just let them set so I would not need to do any drilling at all, I was advised if to use Wet fix brackets...

Are wet brackets just as strong as dry if so why use dry ones if you could cut out all the time and drilling ?

I've never heard of a wet fix bracket unless you mean a post stirrup, "J" Bolt or a "U" Bolt. If so these would be much stonger than any drill in anchor that is including chemical anchors.

You betcha, Bazza. The cast-in bolts put more uniform stress on the concrete. The only advantage of drilled-in anchors is accuracy of placing, i.e. measure location, then drill. If the anchors are near the forms, support them with scrap timber attached to the forms at accurate locations. Elevate the scrap with spacers to finish the concrete around the anchor. Much better construction IMHO. For distant locations, e.g. interior of the slab, drilled-in is probably better though, unless you can position cast-in anchors accurately (good luck on that).

Joe