I need to cut a new 32" exterior door in to my masonry block home. the location of this will be right at the corner junction of two exterior walls. The type block in this area is the shorter 4" height...not the typical 8 or 9 inch high hollow core block. I have a flat roof and this door way will be about 2.0 feet below the roof line.
Can I cut flush with the perpendicular exterior block wall and mount my double 2x8 side framing flush with the perpendicular corner wall...or should I cut so there is at least some of the return wall stub left in the corner ?
Also...do I need to support the opening during cutting will some type of post/ceiling support..?..or will the block construction be strong enough to cut out the 32" x 90" or so opening and install the reinforced sides (double
2x8's each side) and header (5 2x10's) without a temporary support system ?