Replacing casement windows

I'm planning to replace my windows and side over the existing T1-11. The old windows have a brick mould trim around them butting up against the T1-11. I would like to remove the brick mould and get new windows with nailing fins to install (rather than "replacement windows").

How exactly would I integrate the new windows with the T1-11 considering I will eventually side over the T1-11 with either Hardie or vinyl?

Should I just replace the brick mould over the nailing fin,
or first build out the brickmould space with strips of OSB,
or...can I side right up to the new window and eliminate the brick mould (assuming I get to the siding soon).

Thanks much, Jst

 

What type siding will you be replacing the T1-11 with? If vinyl, order your windows with integrated j channel. If a plank or hard surface such as t1-11 or hardie, etc. then reinstall brick mold over the nailing fin and bring your siding to it. Some manufacturers take the brick mold into consideration and it is already installed on the frame (vinyl), and you just bring your siding to it. If you leave the t1-11 in place, you will have an issue with the jamb extension, since it will be 5/8" set further back than normal installation, which is against the osb. Not a problem as long as you address it as you order your windows.

 

The T1-11 will stay. Could you clarify what you mean by the jamb extension? Do you mean the interior? I understand that I should probably build out the window prior to installation, or else the new siding will stick out past the window, I just wasn't sure how to do this and keep the brick mould or not?. If this is addressed when ordering the windows, how does that affect the windows?

 

I would take a piece of plywood or osb the same thickness as the T1-11 and put it under the new window so the entire nailing flange is on top of the T1-11. If you get windows with the built in J-channel that will save the trouble of installing it later. If you use other siding besides vinyl then forget the built in J-channel and do whatever is normal for the siding. Either way the nailing flange needs to be over top the T1-11 as this is the base for the window and siding, same as if it were osb or plywood. A house is sheated then the windows are placed into the holes cut in the sheathing.
Hope this makes sense to you.
Putting the brickmold over the nail flange is up to you if you will be a while getting the siding done then you may want to put it on to cover the flange but if it is not going to be used in the siding plan then it would be a cost factor that would depend on how long it is before you do the siding.

 

Thanks for the reply.

So...installing the window on top of the T1-11 (or flush osb) will bring the window out further necessitating the jamb extension on the interior that Chandler mentioned...right?

Also, how should waterproofing be addressed in this situation? Should I just put flashing tape over the nailing fin. If I don't do the siding right away, there won't be any Tyvek to work with.

Thanks again.

 

I agree that if you decide to leave the t1-11 that you would install strips of OSB or plywood around the rough opening where your brickmould once was. Then you would want to take some strips of Tyvek and paper the bottom face of the rough opening, then the sides, and install the window w/nailing flanges on top of that. Ideally, this will allow you to incorporate new housewrap later when you are ready to install siding, at which time you'd want to tape over the nailing flanges with a peel and stick membrane like Tyvek straightflash, Grave Vycor Plus, ProtectoWrap, etc.

If you're using a vinyl window you'll need an interior jamb to trim the window anyway... so building the window out another 1/2 - 3/4 isn't a big deal. You want the nailing fin to be at the same level as your sheathing, which will be the t1-11 if you decide to leave it on.

 

Thanks everyone.
So, the brick mould would be optional since the siding can but up against the new window itself, right?

 

Correct.

But personally, I like to see some sort of exterior trim around a window- not just because it looks more traditional- but because if you ever need to remove/replace the window, you just have to take the trim off... not all the siding.

 

Good point. Thanks again.