Flash a new window w/o WRB?
So I have a 50 year old house with cedar lap siding and I found out that the exterior sheathing of the house is some kind of drywall type product.
I want to install new construction windows by cutting back the siding wide enough for 1×6 trim around the window. The current window frames are pretty crappy.
My question… I don’t recall seeing any tar paper between gypsum panels and the siding. So what is the best way to flash these windows? I’d like to do it in a manner where if I ever decide to remove siding and install new siding in the future, the WRB can be tucked under the flashing. Is that even possible?
Thanks in advance
I would look into liquid flashing. I'm about us use a product by Proseco called Fast Flash for setting a new construction window in an old house (no sheathing). FastFlash can be bought online and will adhere to anything including consolidating the cut edges of gypsum product you mentioned. Suggest buying a sausage gun if you have multiple windows. If you have large gaps, fill with Proseco Joint and Seam Filler first. See Matt Risinger on youtube.
If you're changing the trim width, add another nailer (stud) on side the king stud for catching the siding/trim
Thanks for the reply. I’ll look into the Fast Flash.
So if I use that liquid flashing now, and then 5+ years down the road I tear off the siding...I assume that I can install a wrb over the liquid flashing and re-flash the windows the conventional way?
Yes you can run your wrb over the Fast Flash and then reflash the wrb using a tape compatible with Fast Flash, probably whatever tape is recommended by the maker of the wrb.
Using FastFlash is an expensive way to flash a retrofit window but I endorse it and similar liquid flashing for that application. I've been using liquid flashing for a few years now because you can create a watertight "area" around the retro window where before we could only *try* to tuck flashing under existing siding and hope the high quality caulking would keep the water out. With liquid flashing I can almost make an outward facing "pan" around the window, seal the siding at the joint where it meets the wall sheathing then cover the entire thing with trim finished in the regular way.
A caution: the flashing is tenacious so don't be sloppy and it builds up so make sure you smooth it well cuz ur not going to shave off lumps very easily.
Thanks for the info, I’ll give that a try.