breaking through cinder block bearing wall for glass slider installation
I was taking down the sheet rock and the outside singles on my two story 1960 cape with a basement when to my amazement the house is made of cinder block up to the second floor where it is then made of 2x4 construction, most like a dormer. The place where we want the opening already has a window. The header attaches to the second floor plate and on the bottom the header is attached to the cinder block. The doors are 80 inches high by 6 feet wide. Any information on the size of header needed and any safe tips on taking down the cinder block without the top floor colapsing would be greatly appreciated.
Henry Shirley NY
Re: breaking through cinder block bearing wall for glass slider installation
You have two options. One is to install a concrete header, available from any concrete masonry provider. You would knock out the block to the size of your door opening, I would put a form around the opening and fill the cells with concrete for strength, since you're messing around with a bearing wall. Then you set the pre-cast header on the top of the opening and re grout it. If you're not familiar with this type construction, you may want to hire it out.
The other option would be to frame it with wood. With that size opening, I would use either 2x10 or 2x12 headers, with a piece of 1/2" plywood nailed between them to give it a 3 1/2" width. That would carry your outside walls pretty sufficiently. You'll need to make sure the bearing points of the end of the header are resting on good solid legs too. Either cut out the block wider than the doorway, build your door jacks on either side, anchor them to the block if possible, and nail off your floor and top plates.