Patching Concrete Block?

[CHuDWah]

The inside walls of my concrete block garage have some holes from toggle bolts the previous owner used to hang stuff - they're 2" or so in diameter. Never having patched masonry, I have some questions:

1. What's the best filler to use, preferably premixed?

2. How do I keep the filler from just pushing through the hole into the hollow block? A backer of some sort?

3. Should I build up the patch with thin layers, or just one thick layer (I'm guessing the latter)?

4. Any other advice?

 

[Bighead38]

Are you doing it just for looks?

 

[The Cobbler]

push some insulation in the holes. mix up some mortar and trowel it in, leave it sit bit to firm up . scrape off anny that is sticking out. let it harden.
repeat

 

[CHuDWah]

Are you doing it just for looks?

Yes - no structural problems

 

[NYBODYMAN]

What about mortar caulk? Squeezes out in a caulk tube. I used that on my block basement for the same thing and it worked fine.

 

[Leaflessshadetree]

1. Chisel all of the holes so the patches will lock in.
2. Pack the voids with crumpled news paper.
3. Wipe one hole with a wet rag to remove any dust or loose chips.
4. While that hole is still damp Mix up enough hydraulic cement to patch 1 hole.
5. Trowel it in smooth with the wall (it sets up quickly).

Repeat steps 3-5 for each hole.

 

[mm08822]

1. Chisel all of the holes so the patches will lock in.
2. Pack the voids with crumpled news paper.
3. Wipe one hole with a wet rag to remove any dust or loose chips.
4. While that hole is still damp Mix up enough hydraulic cement to patch 1 hole.
5. Trowel it in smooth with the wall (it sets up quickly).

Repeat steps 3-5 for each hole.

Hydraulic cement is best - it expands slightly vs. shrinking as mortar does. It sets up quickly so you can progressively patch a hole by building it up in a short time.
Finishes off nicely too.

 

[Bighead38]

If you don’t want to mess with cement just use some spray foam. Cut it even with the wall when it drys.

Personally I would just mix a small amount of something quick setting and patch it.

 

[DTE]

I use Alex painters caulk, they make a Slate grey that matches unpainted block fairly well. It takes 2 to 3 applications to do a nice job.

 

[CHuDWah]

I use Alex painters caulk, they make a Slate grey that matches unpainted block fairly well. It takes 2 to 3 applications to do a nice job.

I neglected to mention we're going to paint (actually repaint) the wall after it's patched, so color match isn't a concern.

 

[DFB]

I second using a quick set hydraulic type mortar for an expanding fast patch

 

[juddspaintballs]

I've patched concrete block in my basement with hydraulic cement. It was easy to shove into the hole by hand and it set up very quickly. I'd use that.

 

[CHuDWah]

When I ask for and get advice, I think I should report the results, so...

I used hydraulic cement. The directions said to chisel the back side in a "V" shape to hold the patch but the holes really weren't big enough to do that - they were broken through in pretty much that shape anyway. I wiped out the dust with a damp rag and wet the holes with a spray bottle. I mixed the cement as directed (3:1), packed as much as I could in the hole, and leveled it off with a putty knife. It hardened quickly and hasn't fallen out so I guess I'm good.

Still have some small masonry screw holes to fill - I'll probably use concrete caulk for those. Then ready to paint...

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[macdabs]

I can’t believe no one mentioned Tiger hair or body putty . It is easy to work with sands nice and lasts forever .

Mac