Filling bolt holes in concrete

[breckrider]

I need to move a post on a metal fince that is attached to a concrete pool deck
with redhat sheathed bolts. 4 of them. I've pulled the bolts out so there are now
4 holes in the concrete 3/8in in diameter. I'm drilling new bolts holes 3/4in from
the existing holes.

What should I use to fill the old bolt holes that will withstand being drilled so
closely to?

 

[Eddie_T]

Not sure if it would apply here but I watched a friend set bolts in concrete for a tire changer by melting sulfur and pouring it around the bolts. I suspect that it might work as a hole filler as well.

 

[breckrider]

I wouldn't have any idea how to do that.

 

[oldognewtrick]

Quickcrete makes a masonary caulk in a tube thats gray and looks like mortar. I've used it a lot on small cracks and voids over the years and had great success with it. You can find it at the big box stores or most hardware stores.

 

[Steve123]

What should I use to fill the old bolt holes that will withstand being drilled so
closely to?

I don't think that is going to work.

Best would be to find a way to re-use the old holes.

Is this just a slab, maybe a few inches thick, or a deeper pier ? Got a photo ?
Are you replacing the post, or just that old mounting has loosened up ?

 

[breckrider]

It's a swimming pool deck. About 4 inches thick with an exposed pea gravel top.
I can't reuse the holes because I need the gate opening to be wider. I don't currently
have a picture. I'm looking at this product or hydraulic cement.

 

[oldognewtrick]

Sika makes great masonary products. That should work ok. Just read the directions on the package before you use it.

 

[breckrider]

Sika makes great masonary products. That should work ok. Just read the directions on the package before you use it.

Thank you!

 

[Eddie_T]

I wouldn't use anything as a filler that doesn't approach the compressive strength of concrete. A sand cement mix tamped into place (using a hammer and a dowel) might work if the mix is dry enough not to shrink as it cures.

 

[bud16415]

Way more than you would need, but maybe you have some other places to fix you could use it on. Watch the vids.



Rapid Set 25 lbs. Cement All Multi-Purpose Construction Material 02020025 - The Home Depot

 

[Snoonyb]

In CA we're required, when doing additions, to dowel into the existing foundation and set the new rebar for the addition. I use the SIKA caulk, fill the hole, insert the rebar and It's dry and firm in a matter of seconds, any purged from the insertion runs down the foundation about 2" and is dry shortly there after.

I've used the cement-all on quick repairs on high traffic exit walks, porches and steps.

 

[user 4883]

IMO new holes that close to the old holes is a structural problem and requires full strength of the surrounding area. I would core drill a hole to encompass all 4 holes and then mix up some concrete and refill the hole. You could incorporate pins/rebar to tie into the surrounding structure. A handful of pea rock to press into the surface of the wet concrete to match the existing surface. Your big box store should have a core drill for rent.

 

[breckrider]

In CA we're required, when doing additions, to dowel into the existing foundation and set the new rebar for the addition. I use the SIKA caulk, fill the hole, insert the rebar and It's dry and firm in a matter of seconds, any purged from the insertion runs down the foundation about 2" and is dry shortly there after.

I've used the cement-all on quick repairs on high traffic exit walks, porches and steps.

THis Sika high strength formula starting setting up almost before I could get it out of the tube. Bent my caulk gun.

 

[Jeff Handy]

I like the idea of hydraulic cement.
It sets up hard and expands tightly into hole.
You would have to coax it in there, with a few small hand tools.
I have also used anchoring epoxy.
Not cheap just for four little holes, but it sets really hard.