# Window replacement questions/opinions



## pourlepayssauvage (May 16, 2013)

After the first winter in our new house its obvious with the cold coming thru them that we need the windows replaced, which have been there since about 1983.  I've installed windows during a new construction before - I built a camp several years ago - but I've run into a couple of questions that I think I know the answer to but I would like to have others opinions on.  The basic issue is the house has T1-11 siding which serves as the sheathing and the exterior - sheetrock/insulation/ T1-11.  The original windows are wooden sliders.  Here is what they look like from the inside;




and the outside;


Someone did a good job trimming them on the inside however as I started taking things apart none of the jamb extensions etc were insulated well - if at all.  It appears that the windows were screwed into the center of the studs/header leaving a gap underneath and an exterior sloped piece of wood was butted to the bottom of the window to act as a sill drain.  Image of what I'm trying to describe;


Its tough to see the slope in the image but that piece of wood sits on the cripples and butts the bottom of the window.

So my question has to do with replacing them.  My current thought as to how to proceed is to take everything out and get down to the studs.  If necessary, cut out a strip of the T1-11 to facilitate that. Install the fins of a new construction window to the studs/header etc.  Flash the window to the studs beginning at the sill which would go over the exterior (see image), Install the T1-11 strips back in place - flash to the exterior T1-11 and trim.  It would look like this;
1;
	

		
			
		

		
	



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3;
	

		
			
		

		
	




I think that is the best way to go.  The other options I have seen are attaching the window directly to the t1-11 as in a new construction -- at some point I am going to put another exterior over the T1-11 - probably vinyl - so this may have merit  - but its a year or more down the road before that will happen. And I suppose I could cut the fins off a new construction window and center/screw it onto the studs like the originals - which would save some interior trim work/time/money.

Opinions?  Ideas?  Something completely different I haven't thought of?


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## begreen (May 17, 2013)

Are the windows single pane? I'd be tempted to correct the sealing issues and add stormwindows if needed and call it a day.


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## tyler pekkins (Jan 17, 2015)

pourlepayssauvage said:


> After the first winter in our new house its obvious with the cold coming thru them that we need the windows replaced, which have been there since about 1983.  I've installed windows during a new construction before - I built a camp several years ago - but I've run into a couple of questions that I think I know the answer to but I would like to have others opinions on.  The basic issue is the house has T1-11 siding which serves as the sheathing and the exterior - sheetrock/insulation/ T1-11.  The original windows are wooden sliders.  Here is what they look like from the inside;
> View attachment 102319
> 
> 
> ...



I think you should replace the whole window or you can attach the stormwindows there. By replacing whole window you can be sure about your windows . As you are saying that these are very old ones  so they must be replaced now . Repairing windows can't do much .


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## Ncountry (Jan 17, 2015)

I would instal new construction windows using the nailing flange, esp. if you plan on siding over the t1-11 soon. Put a good bead of silicone under the nailing flange when installing and flash with the window tape.


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## DickRussell (Jan 17, 2015)

pourlepayssauvage said:


> .....and an exterior sloped piece of wood was butted to the bottom of the window to act as a sill drain.
> 
> ....  My current thought as to how to proceed is to take everything out and get down to the studs.  If necessary, cut out a strip of the T1-11 to facilitate that. Install the fins of a new construction window to the studs/header etc.  Flash the window to the studs beginning at the sill which would go over the exterior
> 
> .....  The other options I have seen are attaching the window directly to the t1-11 as in a new construction -- at some point I am going to put another exterior over the T1-11



Take a careful look at any window vendor's website where they show their installation instructions. Ask yourself where the exterior shell air barrier is. If it is at the sheathing/siding (T-11) layer, then that's where you need to maintain the air barrier connection between sheathing and window, rather than to the stud, unless there is an air barrier connection between stud and sheathing (sealant).

In most installation instructions, it is suggested that either a sloped piece (eg. clapboard) be placed under the window, with flashing over that and running out over the "Water Resistive Barrier" (WRB), which would be housewrap or, in your case, the T-11. The window flange goes over that. The idea is that any water that makes it way past the window frame and onto the flashed sloped piece under the window should make its way out to the WRB and run down and out. To allow that, the bottom nailing flange should not be sealed to the flashing or WRB, at least not along its entire length, so that water has an exit.


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## Hogwildz (Jan 17, 2015)

Nail them over the T1-11, sealing them well with silicone or a good caulk under the nail flange, then you could even weather tape seal over the flanges, then add a 1x4 wood trim framed all the wall around over the nailing flange.Then paint, stain or even cap the wood with aluminum trim. Spay inside between the studs and the window with window & door low rise spray foam, reinstall your interior trim, done.

Once you have the old window out, loosen the T1-11 edge above the window and you can slide a drip cap up there behind the T1-11 then renail/screw the T1-11 back tight, which will also secure the drip cap, which will cover the top of the window, and with a drip edge on it, send any water to the ground, keeping any water from running in and down behind the window.


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