Many older homes in Arizona have their plumbing pipes installed inside the cells of block walls. This protects and hides the pipes but someday, if there's a leak, this is what your plumber will have to do to your wall to get at them.
When they're finished with the plumbing repair, they leave you with a big hole and instructions to contact a mason. Nice for the mason; not so great for you.
I make repairs like this regularly. If you would like to try to handle it on your own, here's what I do.
The first step is to cut out all the blocks that are less than full. In this example, the blocks are 16 inches long by 4 inches tall. I usually don't have to remove the entire block, just the "face" about 2 inches deep.
To make sure I don't make cuts where I don't need to make cuts, I mark every mortar joint I plan to cut with a black Sharpie marker.
I use two different masonry diamond blade saws to do the cutting. I cut the head joints (vertical mortar joints) with a grinder that has a 5 1/2 inch diamond blade on it, specifically for cutting masonry. I cut as deep as the blade will go, being careful not to cut into either the block above or below the joint. After that, I use a masonry saw with a 9 inch blade to cut the marked bed joints (horizontal joints). I use the 9 inch blade so that I can get in at least 2" because I can't get that deep with the grinder.
Once the cuts are made I use a Bulldog rotary hammer drill, set to hammer only, with a 1 1/2 inch wide flat chipping bit to carefully remove the block faces I just finished cutting all around.
Here's what the wall pictured above looked like after removing all the damaged block faces:
As you can see, I had to cut out about 15 block faces. After chipping out the blocks I chipped away any remaining mortar that would get in the way of installing the new block faces, being careful not to damage any other blocks. I also used a leaf blower to blow all the dust from the blocks.
Next, with the 9 inch saw, I cut the faces off, 2 inches deep, on both sides of 8 blocks that I brought to the job with me. I purchased them at Home Depot, along with a 90 pound bag of masonry mortar.
Once I had the cuts ready, I laid them all in place to "dry-fit" them before mixing the mortar. I cut a few of them to be less than 2 inches thick so that they would clear the horizontal section of PVC pipe.
From there all that was left was to install the face shell blocks with mortar, starting from the bottom and working my way up. I carefully placed each block to ensure they were all properly aligned with each block level, flat and plumb.
Double striking the joints to match the rest of the wall put the finishing touches on it.
After allowing the mortar to cure for 24 hours the homeowner will paint the new blocks and no one will ever be able to tell that that big hole was ever there.
If you would like to try a repair like this on your own, follow these basic steps. If this sounds like a job that you want no part of, give me a call.
Repairing walls broken out by plumbers is a specialty that not every mason gets a lot of practice doing. I've been doing these kinds of repairs for years and I'm very good at this. I'm licensed, bonded and insured and all my work is warrantied against defects in workmanship or materials.