Cinder Block Foundation Repair. Is it DIY-able?

I have an old garage with some rotted cinder blocks in one corner that I’d like to repair before the damage gets any worse. I'm looking for advice on potential repair options. The cinder blocks are laid directly on top of the concrete slab, which has a large crack running down the center. This crack causes the damaged corner to be the low point of the garage. It looks like the previous owner tried to reinforce the wall by pouring concrete into the cores of the cinder blocks, but unfortunately, some of that fill has also crumbled away. I came across an old post here where someone had a similar issue, and the general recommendation was to frame around the damaged area and pour new concrete. I have a couple of concerns about taking that approach in my case: The damage doesn’t seem quite as severe as in the other post, so I’m wondering if a full pour is necessary. Could I instead just do a patch or a parge coat? I’ve been considering parging the entire foundation anyway. If I do need to go the framing and pouring route, I’m not sure how best to do that. The sill plate in that area sits flush with the edge of the cinder block, so I’m unsure how to frame it out in a way that allows for a proper concrete pour. Any advice or shared experiences would be appreciated! submitted by /u/mushroomgnome [link] [comments]

Jun 10, 2025 - 23:58

Cinder Block Foundation Repair. Is it DIY-able?

I have an old garage with some rotted cinder blocks in one corner that I’d like to repair before the damage gets any worse. I'm looking for advice on potential repair options.

The cinder blocks are laid directly on top of the concrete slab, which has a large crack running down the center. This crack causes the damaged corner to be the low point of the garage. It looks like the previous owner tried to reinforce the wall by pouring concrete into the cores of the cinder blocks, but unfortunately, some of that fill has also crumbled away.

I came across an old post here where someone had a similar issue, and the general recommendation was to frame around the damaged area and pour new concrete. I have a couple of concerns about taking that approach in my case:

The damage doesn’t seem quite as severe as in the other post, so I’m wondering if a full pour is necessary. Could I instead just do a patch or a parge coat? I’ve been considering parging the entire foundation anyway.
If I do need to go the framing and pouring route, I’m not sure how best to do that. The sill plate in that area sits flush with the edge of the cinder block, so I’m unsure how to frame it out in a way that allows for a proper concrete pour.

Any advice or shared experiences would be appreciated!

submitted by /u/mushroomgnome
[link] [comments]