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Discussion Starter · #1 ·
I am about to replace about 17 old wood windows in a 1930's house. I am also planning to install vinyl siding over the wood dutch lap siding. The exterior wall are insulated.

The plan is to use New Construction windows, with built in J channel. I have never installed windows, so I was hoping for a few pointers. I have already removed all the casing from the inside and measured the rough openings.

Can I just:

1. Remove old windows.
2. Furr out the rough opening so that it is flush with the existing siding.
3. Screw window in.
4. Apply tape or aluminum flashing to bottom, sides, and top.
5. Add Vinyl siding


Is there any need for house wrap or is it fine to install vinyl directly over the dutch lap?

Anything I am missing? Do I need to take any additional steps when flashing the windows?
 

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Are you sure you want to put vinyl over wood rather than striping the wood? I know it can be done, but I think you'd get a better result if you strip it first.

Anyway, for the windows just follow the mfg instructions and you'll be fine. I don't know if anything is different with your windows having an integrated J-channel, but the process is generally something like this:

- Flash the sill and about 6" up the sides using something like Grave Vycor
- Caulk sides and top of window opening (not the bottom... this could trap moisture
- Install window and shim it to be level and square. Check your diagonals. Also measure the width of the window at the top, middle and bottom. With larger windows the sides can bow out a bit, so if then middle measurement is larger than the top/bottom you'll need to correct this
- Secure window flange, generally with roofing nails
- Flash over flanges, sides first and then the top (not the bottom).

If you're leaving your wood siding, I'm not sure how you would build out the window to be flush with the vinyl. Hopefully someone else will chime in.
 

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Discussion Starter · #3 ·
Are you sure you want to put vinyl over wood rather than striping the wood? I know it can be done, but I think you'd get a better result if you strip it first.
Vinyl has to go over some type of wood, correct? Why would putting it over the existing siding be any different tham stripping the siding, putting up osb, then vinyl?
 

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I've just heard that vinyl looks better when installed over a flat surface. I don't have any personal experience installing vinyl, but installers around here that I've spoken to recommend either stripping existing siding, or adding fairly thick rigid foam board (3/4") to provide a flat surface.
 

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you mean you want to drain the water your window flashing diverts directly on to the under lying wood siding? does that make sense to you? or is it better to drain on to a water resistant barrier?
 

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Discussion Starter · #8 ·
you mean you want to drain the water your window flashing diverts directly on to the under lying wood siding? does that make sense to you? or is it better to drain on to a water resistant barrier?
Yes, that makes sense to me. This wood siding has been resisting water for probably 50 years. Why would it stop working now?
 

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Yes, that makes sense to me. This wood siding has been resisting water for probably 50 years. Why would it stop working now?
I'd listen to Mr. Struble if I were you.....:yes:

I'm sure you've heard the horror stories of people covering up perfectly good wood siding and creating moisture problems that reek havoc with the wood under the vinyl.
 

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Yes, that makes sense to me. This wood siding has been resisting water for probably 50 years. Why would it stop working now?

because now it's not acting as a siding,it is now an underlayment

you will be nailing the new siding into the wood siding i presume,and what happens when we nail into something?what do we make?
 

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I recommend stripping the old siding off. We had vinyl siding done a couple yrs ago and had the old 12" siding removed. We then used Typar Building wrap that prevents water penetration but allows the walls to breathe so moisture from inside the house can still get out.

Putting vinyl over old siding really makes the old siding your moisture barrier which it won't do well as mentioned before (won't get a chance to dry out with less air movement). Plus it is so much easier to put vinyl over a flat surface.

Since vinyl is not water proof and rain will get behind, I really recommend re-wrapping the house. This wrap will be your rain barrier.

Good luck.
 

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