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Installing prehung door in CMU wall

2422 Views 5 Replies 6 Participants Last post by  dakzaag
I have a client who wants to remove a 3' wide window in a CMU wall and install a new 3080 door in its place. I'm assuming the block will be mostly hollow and also that the window already has a lintel in place above it. What is the simplest way to prepare the opening for the new door and frame, ie. do I need to fill all the adjacent cells, bucking, etc. First time I've tackled a project like this so any help would be greatly appreciated! Sorry if this has already been addressed in the past, but I am new to this forum. Thank you.
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If you have never done one in the first place, You are in over your head, try finding a guy in your area who has and Pay to learn.

Pay a mason to set the frame
How much play do you have for the RO?
Wood frame prehung here.
If there is room in the RO I will use PL adhesive rated for wet conditions and pressure treated lumber and glue and nail pressure treated plywood to the block. Then screw the door jambs to the plywood strips.

If no room for plywood strips I drill out half a dozen holes in the block on either side and then drive in pressure treated plugs, then run my screws through the jambs into the plugs. Make sure the door is right then spray foam into place.

You don't say which part of the country you're in, but if you're in a hurricane zone be ready to drill the lintel and footer, epoxy rebar, and concrete the hollow block.

There are standard masonry doors, just for your information.

Grouting the adjacent cells is pretty important.

Wedge anchors usually will fail.

Did I mention that a standard masonry door is different than a standard door?

The jams should be filled with grout and it is best to have a tie strap back into the first block about every other course. This is very rarely done in a retrofit, but if possible, it is great insurance for a long lasting door.

And finally, I might not have mentioned that there are standard masonry doors that are different than regular doors and you should use one in this situation.
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