Window Bucks in old structural brick
I own a 1900 structural brick building (two wythe on all sides except front is 3) in Richmond , Virginia. The brick is obviously extremely brittle as is the mortar. Sadly the original windows were replaced with cheap vinyl windows and the original wood window sills and window jambs/ frames housing the metal pulleys and weights was covered with aluminum flashing. Not surprisingly this caused plenty of wood rot , enough windows weren’t functioning and I had to remove several of them to get rid of the rotten wood. My question for folks here is does anyone have a technique for re building the window frames ? The brick and mortar is so brittle no anchors will work. The way they were attached is the window bucks had wooden wings nailed to the jambs that were embedded into pockets in the brick and then stuffed with mortar. I should add all the window openings in the brick have a sort of flange on the exterior, in other words , the window opening is wider inside the structure and the outside the bricks extend 2 inches into the opening. I know any wood I use should have a capillary break between it and the brick . My thought was to use non treated pine wrapped in grace vycor to protect the new window frames. Would tension alone (building the frames so tight they hold themselves in) be ok? If I use treated wood I’d need to source kiln dried treated so it doesn’t move too much. Anyway just figured someone on here has done this before and would have a way. Thanks so much.
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Typical way is pack out the sides with 2x lumber so you have about 1/2" gap on either side of the new window. I put nothing on the top or bottom. The wood on the sides doesn't see, or least should not, any moisture. I put a bead of spray foam between the brick and the 2x to air seal before tapconning it in place. One thing to watch is if you have shallow brick arches, the original wood framing is semi structural, in this case you want the new 2x pieces be installed tight to support the arch.
If you have brick window sills, I would recommend a formed metal pan that extends past the existing sill. There is no way to make brick sills water tight in the long run. If you have stone sills check the top of the stone is sloped slightly to drain and there is a drip edge on the bottom. The bottom drip edge is missing in a lot of older homes and it really helps with keeping water off the brick bellow, simple to add in with a 1/4" diamond wheel on a grinder.
I think you will find the original windows were nailed into wooden blocks that the masons had installed in place of bricks for that purpose.
I did not have any luck finding photos. I did capture the image from this video.
Season 2 EP26 4 minutes
https://www.youtube.com/watch?v=d3VYXPjIJMM&t=3s
Walta