# Filling Big Hole in Block Wall



## hurbear (Feb 29, 2008)

While starting the process of finishing the basement, I pulled down some of the old cheap styrofoam they had stuck on the interior of the block wall only to find a 6"+ size hole where an apparent woodstove pipe used to exit the basement.  The hole is not noticable on the outside because of a floor bed they had built up over the years.  The blocks are all hollow, so I'm wondering what the best way is to go about filling the hole.  I'm hoping there's a solution other than knocking out all the "holed" blocks and replacing them.  Any thoughts would be appreciated!


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## guyod (Feb 29, 2008)

I would stuff the whole with anything your can find, rocks, scrap lumber. then use spray can foam insulation to fill in the rest of the way.  If you never used this stuff it expands at least 2X over the coarse of an hour and do not get it on your hands.


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## hurbear (Feb 29, 2008)

Right now I have it stuffed with insulation to help keep the cold out, but my main concern is structural integrity and the blocks crumbling away even more.  I don't know if a regular concrete/mortar mix is sufficient for that type of hole or if there's another product out there I should be searching for.


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## guyod (Mar 1, 2008)

As long as its just that one block that is broken up and it is more than 2 coarses down i would not worry about it. 

If you do choice to fix it i think replacing the block would be the easiest. with a chisiel it comes out pretty easy. But if you do not feel comfortable with that then break out the cracked parts of the block then choke hollowed hole up to the block you are working on then mortor in some bricks


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## glennjanie (Mar 2, 2008)

Hello Chris:
You could stuff paper tightly into the cores under the hole, mix a small amount of Sackreet or Quickreet barely moist, put a backer on the outside and start stuffing the mix into the hole. Use a damp sponge trowell to work the finish into the block and keep it from cracking when it dries. Sprinkle it lightly with water and re smooth the face several times at 15 minute intervals. Give it an overnite to cure then take the cover off the outside and trowell some mix into the outside to smooth it up.
Glenn


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