Sliding Patio door for Bi-Level House

Old 04-04-19, 07:21 PM
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Sliding Patio door for Bi-Level House

I am renovating a Bi-level house. Underneath deck there are 2 windows and i am replacing them with sliding door. There is about over 3 feet concrete blocks and then the windows. Header is exactly what i need for sliding doors. When i take out windows and concrete blocks I want to make sure rough frame is good so wanted some advise as i might need to do something in bottom especially that will be end of concrete slab. Here is what i was thinking
1. Remove windows and blocks. Blocks wont come exactly straight line and will break or crack when i sledge hammer them. so when i frame what should i do for uneven gaps. ?
2. At bottom it is concrete so i might need to use pressure treated wood i am thinking. On side since half is concrete blocks i might need to use same pressure treated wood .
I am more worried about bottom to make sure water or anything doesn't come in and how do i do the job correctly. see picture.
3. Presently i have taken out all the sidings and i will be installing the plywood over gypsum and then i will need to install the door (i am thinking).
4. For sliding door do i need to also use door sealing tape? What about bottom?
Thanks in advance for your help.
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Old 04-04-19, 09:15 PM
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You would not do this with a sledge hammer, you would use a concrete saw to cut the block cleanly in a plumb line that follows the inside edge of your king stud. The idea is that you will replace the jack stud with a new one that goes all the way to the ground. You would mortar the cores / edges of the cut blocks and grout them so they are solid.

If you wanted to tooth out the opening instead, you would cut replacement blocks to length then turn them around so the flat end block side faces your new jack stud. Shim up and tuck point the new blocks with mortar mix. Put rebar down the open core and grout them solid.

Yes, you use treated wood and acq approved fasteners. Anytime you have a door at grade it is a leak waiting to happen, so you need a good dropoff at the slab edge. (1" minimum but more is better... depends on the kind of drainage/slope you have back there.) If your blocks go below grade, you must remove them so that you can pour a solid edge to the pad. That pad must not extend beyond the new door sill nose.

You can install a pan flashing under the door if you are concerned about leaks. You caulk under the pan flashing with concrete sealant then the door gets caulked to the back lip of the pan flashing when you are ready to install it. And you use butyl flashing tape for any door with a nailing fin. (Your door better have a nailing fin.)

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