Doors and Windows - installing windows in old house with drop siding

Hi, I have a old house that has wood drop siding that I'm wanting to install new windows in. I a few questions about it since this is drop siding it will have a small opening between the siding and the brick molding due to the overlapping. Also this house has vinyl siding on top of the wood siding and currently there is 1x6 framing around the old windows that butts up against the vinyl siding ( I'll be using same technique until next year when I get new vinyl siding installed) and there is NO plywood inside the walls. Whats the best procedure for weather proofing this installation due to the overlapping siding that the brick molding will be nailed to?

Also... there will be a couple of raw openings where the siding is cut back too short and exposing the studs some and the brick molding will be against the studs but I figure on that just nail some wood on the studs to bring it even and rest will be same sealing/installing procedures as the other unless someone has a better idea on that... Thanks

Oh, right now I'm looking at using wood windows unless vinyl twin double hung are reasonably priced in this size. Raw opening is roughly 68 1/2 x 57 1/2

It sounds like you are describing a VERY old house, if there is no sheathing under the siding. If there is nothing under the siding, I would consider ripping it all off and installing ply or OSB sheathing, then house wrap or felt, then reside. As for those old windows, they were likely held on with nails thru the 1x trim. Removing the inside and outside trim should free up the windows. Maybe some nails at the sill. Do they have weight pockets??? You could then replace them and install new trim after flashing with adhesive flashing.

Thanks for the reply. I thought about ripping siding and start back but cost is what worries. I have thought about installing OSB over top of the siding, wrap and install new vinyl.

Your plan extends everything out and makes the windows sit in a hole. Harder to waterproof.

Your plan extends everything out and makes the windows sit in a hole. Harder to waterproof.

Nah, I'd also bring the windows out also.

Here's my two cents.

As far as building out the window rough openings is concerned, I'd pad them out so that they are level with the surface of your drop siding. Treat the drop siding just like plywood sheathing, and put some building paper or housewrap over it to act as a water resistive barrier.

By putting Tyvek over the drop siding before you install windows or siding, you would just seal the nailing fin to the Tyvek with flashing tape. The voids in the drop siding would be behind the Tyvek and would not be an issue as far as water intrusion is concerned. Air sealing would be done with DAP latex foam around the perimeter of the window, eliminating any air infiltration, so those voids will not be an issue. You just won't want to nail or screw the nailing fin where the voids occur.

Thanks for all for info. Wondering if roofing paper would be just as good as the Tyvek? I can get hold of a roll for free but weight is unknown.
Just found out at work we are going on 4 day work week every other week and it will include maintenance personnel (me) so I'll be having more time for these projects just wish it wasn't so late in the year...Anyway going to gather everything up tomorrow and start on the 2 worst windows Friday...thanks again

You can use felt paper... they used it for years. Only problem with it is that you won't find any flashing tape that will stick to it for more than a few hours.

Since you won't be using any flashing tape, I'd suggest you caulk the nailing flange to the felt paper with some siliconized latex caulking, and lap a piece of felt paper over the top nailing fin as added protection against leaks.

Great, thanks again. I'll look around thru town where some new houses are being built and see if anyone has some extra Tyvek first since it wont take much. If not I'll us the felt installed as you stated.