# Window Sill Rot, New Construction Replacement?



## mpg9999 (Nov 15, 2012)

I have an addition on the back of my house (built sometime in the 90's), and the window sills are rotten, along with the bottom of the brick molding, and one of the windows also has rot on the bottom of the upper sash:





















I can tell the bottom of the brick molding has already been replaced once before. I believe the best option is New Construction windows. I've had two contractors come out. The first agreed new construction is the way to go and quoted 1268 for two simonton 5050 windows and aluminum wrapped trim. The second contractor came out today and said to just do replacement windows. I asked for a quote on both replacement and new construction, and am still waiting on him to email me the quote.

Based on the quote from the first company, I'm pretty tempted to just try and do this myself. I've never done windows before, but am decently mechanically inclined. I've hung a lot of interior doors, mostly slab, and one prehung exterior door. 

I've read this http://www.familyhandyman.com/DIY-P...-window-leaks-with-proper-window-installation but still have some questions.

1. Do most people use preformed plastic sill flashing, or just go with flashing tape? If the sill flashing is slopped, how does the window sit flat on it? does it just contact the bottom of the frame at the back (interior) of the window, or are the raised grooves flat?

2. I'm not sure what kind of underlayment I've got under my aluminum siding. Tar paper probably? In the link I posted above they have house wrap that gets folded around the rough opening on the bottom and sides. What if whatever I have doesn't extend that far? What if there is no wrap at all? 

3. I'm also a little bit confused on trim/brick molding options. I guess it just nails over the nailing fin of the new window? Will the holes that those nails will create in the flashing tape over the nailing fin cause any issues? How does the brick mold connect or seal to the siding? Does it use a J channel (I don't really know what a J channel is or what it does...). What about a drip cap? How is that installed? 

I've got a lot of questions, so thank you to anyone who can help answer them. If I do this I want to make sure I do it right.


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## Windows on Wash (Aug 30, 2011)

That sill is not nearly as rotted as most that we see with rot.

You could still do that window as an insert with some sill repairs/replacement prior to setting the new insert. If you are planning on doing siding, absolutely go new construction and full tear outs.


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## hand drive (Apr 21, 2012)

mpg9999 said:


> I have an addition on the back of my house (built sometime in the 90's), and the window sills are rotten, along with the bottom of the brick molding, and one of the windows also has rot on the bottom of the upper sash:
> 
> 
> 
> ...


if the new window is sized the same as the old then preferably the new will fit into the old window hole. the new window can come with brickmolding installed to the window from factory and you just nail it to the wall after wrapping the windows rough opening with seal-able window/door wrap. the interior trim will need to be re worked as well to match the new window. drip cap sits on the top of the brickmold to give a watershed from the water coming down the wall.


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## joecaption (Nov 30, 2011)

Is that aluminum siding?
If so you may need to order a flat jamb wondow and install your own vinyl brick moulding.
Reason being is if the spacing between the J molding is differant there may be issues. By installing the brick mouding yourself it could be installed nice and tight.
If the new window came with the brick moulding installed and it's bigger then the opening you have your in deep dodo.


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## mpg9999 (Nov 15, 2012)

hand drive said:


> if the new window is sized the same as the old then preferably the new will fit into the old window hole. the new window can come with brickmolding installed to the window from factory and you just nail it to the wall after wrapping the windows rough opening with seal-able window/door wrap. the interior trim will need to be re worked as well to match the new window. drip cap sits on the top of the brickmold to give a watershed from the water coming down the wall.


So is there no nailing flange on a window that comes with brick mold?


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## mpg9999 (Nov 15, 2012)

joecaption said:


> Is that aluminum siding?
> If so you may need to order a flat jamb wondow and install your own vinyl brick moulding.
> Reason being is if the spacing between the J molding is differant there may be issues. By installing the brick mouding yourself it could be installed nice and tight.
> If the new window came with the brick moulding installed and it's bigger then the opening you have your in deep dodo.


Yes, aluminum siding. What is a flat jamb window? I currently have wood brick molding. So is it better to go with vinyl? How does the vinyl brick mold install?


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## joecaption (Nov 30, 2011)

It installs exatly like wood moulding does and will never rot.
A flat jamb window is just that, the jambs are flat, there is no nailing fin.
It's going to be near impossible to install a new window with a nailing fin on an aluminum sided house with out removing the siding. An it's near impossible to remove it with out damaging it.


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## mpg9999 (Nov 15, 2012)

joecaption said:


> It installs exatly like wood moulding does and will never rot.
> A flat jamb window is just that, the jambs are flat, there is no nailing fin.
> It's going to be near impossible to install a new window with a nailing fin on an aluminum sided house with out removing the siding. An it's near impossible to remove it with out damaging it.


Wouldn't the nailing flange rest against the house where the current brick mold is? What would you recommend I do?


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## Windows on Wash (Aug 30, 2011)

Recommended installation type for a DIY application would be a pocket or insert window in this case. 

If you are going to start pulling J-Channel and going full tear out, you are opening Pandora's box. That is not work that is typically suited for a DIY application and you may wind up re-siding that entire exterior.

If you are planning on doing siding at the same time, by all means, a full tear out with new construction nailing flange is 100% the way to go.


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