Flashing over old windows on residing job

[aperezd]

Hi,
I am going to replace the masonite crap, oops masonite siding that is rottening on my house taking it off and installing premium vinyl (the one with the insulation attached in the back). The building code and manufacturer instructions say I need to install sheathing board (plywood or OSB) and weather barrier (tyvec) behind the siding which I plan to do as well.
My question is: How do I flash around the old windows when I install the plywood/OSB and tyvek? All the instructions for window flashing I have seen describe a frame, then sheathing then flashing/window/weather barrier type of new construction installation.
Do I have to take the old windows off and reinstall with new flashing over the plywood/OSB? If I do this I will need to build out the interior trim since the window will be pulled out the thickness of the sheathing. If I don't pull them out and I bring the sheathing/weather barrier to butt against the window frame, How do I flash it before I install the outside trim around the window and cap it? Also any comments on the "Never Rot" PVC trim material? seems like a good alternative to wood that will eventually rot around the window.
Thanks for your help.
Al

[chandler]

Al: welcome to the forums! They are correct in that you will need to install the OSB prior to the siding. If I were doing it, I would pull the windows and doors and reinstall over the osb. Definitely use a metal flashing on top of the windows and doors. I like to use what I call Pella tape (probably comes in other brands) to seal the sides of the windows prior to siding installation. Your tyvek should be wrapped around the openings made by removing your windows, and the windows reinstalled.
The newer poly materials for trim is great. Of course it won't rot, it takes paint just fine and doesn't warp if installed properly. This would eliminate having to wrap the trim with metal.

[XSleeper]

When you say "Masonite" I'm just guessing that you must have t1-11 sheet siding? Large 4x8 or 4x9 sheets that currently serve as your sheathing? Because if you have Masonite lap siding, you would certainly have other sheathing already on the home.

Depending on the style of windows you have, you may or may not need to pull them. That would really be a lot of work that you'd want to avoid if at all possible- perhaps by cutting neatly around the nailing fins (if so equipped), and leaving the masonite in those locations only.

If you have the types of windows with sills and brickmould trim, you would likely want to pull off and replace the brickmould (sills would likely need to stay) which would allow you to get all the sheathing off around the old window without actually removing it. New sheathing would slip under the sill, and new brickmould would be installed on top of the new sheathing.

As Chandler mentioned, using the new flashing tape products is pretty much the new standard practice around windows- especially those with nailing flanges. I would not omit that step.

So I guess I would want to know what style of windows you have before going any farther in my reply. Do they have nailing fins, or not? (If you've pulled off any exterior trim or siding yet, that will make the answer obvious).

[aperezd]

Thanks Chandler and XSleeper for your replies.
I think that I probably will take advantage and replace the windows as I am doing the siding project. Some of them have fogged up the double panes and I think it is a lot easier to install new windows once the wall is stripped down to the 2X4 and a lot safer install doing a "new construction" type of installation of windows with fins rather than a retrofit replacement window with no fins later.

Xsleeper, Belive it or not... I have Masonite lap siding and NO sheathing what so ever behind it. The only thing between the siding and the 2X4 is the black paper which I assume is the weather barrier (kind of a joke as a WB if you ask me). The house was built in the early 90's by Ryland Homes... Pretty cheese uh?
thanks again.
Al

[XSleeper]

Al,

Wow. Yes, I'm constantly amazed by some of the "corner cutting" practices used by some in the industry. Some of it just makes you shake your head.

Installing new windows at the same time will be the best way to go. As each window is removed, you will install your Tyvek (or similar) over the opening. The new window will get nailed on top of the building paper, with one exception- and that is the top. Before the window is installed, you cut a flap in the Tyvek on top and fold it up out of the way. That way when you install and tape the edges of the window, the tape will cover the nailing fin and tyvek on the sides, but on top it will be applied over the nailing fin and then directly onto the sheathing. After that is done, the flap of Tyvek is folded down over the flashing tape and then you can either skip tape it or continuous tape it, (depending on whether you are going for an air-tight installation or not.)

When you side, the j-channel and siding can be installed right up to the window. But some people feel that looks a little anemic, without any trim. So you can always add trim around the window. But with vinyl siding, you probably want something that is low maintenance. Azek #908 brickmould would be one option. It is supposed to hold paint well. Azek also comes in 3/4, 5/4 (which is actually 1") and full 1 1/4" thick (1 1/4" is known as ATM) and can be cut to any width just like wood. But it's pricy. You could also use standard wood #908 brickmould and have it capped with aluminum trim coil which also looks good. Unless you get lots of hail. Sills can be fabricated and can be attached on bottom to make the windows with nailing fins look a little more like the style of window we are used to seeing. Any exterior trim you choose will be purely for looks. But you likely want it to be low-maintenance.

There are also some mouldings that can be applied around windows after the vinyl siding is installed. They basically hang on the vinyl siding like a shutter would, and just give the windows the "appearance" of having trim around them. Some of these mouldings come in fancy profiles, such as if you wanted the home to have a colonial look, with an entablature, cornice and such. So that's something else you could consider if you wish.

[gqlefty]

I have read that there is a class action lawsuite against Masonite siding applications that were installed on houses during a specific time period. Google it and find out more, yours may qualify. Others on this forum may have more info on the subject. I have heard that people are getting their siding replaced FREE !!! I dont know all thats involved but its probably worth checking out !!!!!! You might save some cash !!!

[aperezd]

Thanks gqleftym,
Yes there is, for others that are interested. I already got my check from them, of course it is only a percentage of the cost of replacing your siding (if you get a company to do it). I got about 40-45% of what Amazing Siding and others wanted for the job. Of course by doing it myself, with that money I should be able to add sheathing, replace the siding, reinforce the house for hurricanes (once I get the house naked down to the 2X4s it should be easy and inexpensive to put braces all the way down from roof to slab sill) and maybe change out the windows too. Not a bad deal if you are willing to put in some labor (I might have to pitch in some extra cash if I do the windows). All my neighbors had to put up an amount sligthly over what they got from the settlement just to get the house resided. It should be a fun summer...
I'll let you all know how it turns out.
Thanks to all again.
Al.