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John Oosterling
Roof Valley replacement without reshingling complete roof
John Oosterling

I have a roof valley that looks like it needs replacing, how would I get it replaced without reshingling t he complete roof as the roof is still good.

A. Spruce
Re: Roof Valley replacement without reshingling complete roof
A. Spruce

You don't, because it isn't worth the risk of creating a leak. If your valley flashing are bad, then the roof is probably not far behind it.

dj1
Re: Roof Valley replacement without reshingling complete roof
dj1
John Oosterling wrote:

I have a roof valley that looks like it needs replacing, how would I get it replaced without reshingling t he complete roof as the roof is still good.

1. What do you have in your valley? sheet metal or tar membrane?

2. If it's sheet metal, what exactly is wrong with it? Do you have a leak or it's just the appearance that you don't like? Do you have nail holes or rust holes?

3. What type of shingles do you have? How old is the roof?

keith3267
Re: Roof Valley replacement without reshingling complete roof
keith3267

This is going to need a hands on/eyes on inspection. It won't matter what is possible if you can't find a roofing contractor willing to do it. Get several opinions and quotes from local contractors.

John Oosterling
Re: Roof Valley replacement without reshingling complete roof
John Oosterling
A. Spruce wrote:

You don't, because it isn't worth the risk of creating a leak. If your valley flashing are bad, then the roof is probably not far behind it.

I bought the house a year ago, the roof is about 5 years old ashphat shingles. 20 year shingles and look real good as good pitch on roof, the fellow I had cleaning the eves notice some rust spots (not leaking yet) and he new the previous owners and said they replaced the roof but not the valleys. I just wanted to know and probably get them replaced this summer if possible. Thanks for replying.

John Oosterling
Re: Roof Valley replacement without reshingling complete roof
John Oosterling
dj1 wrote:

1. What do you have in your valley? sheet metal or tar membrane?

2. If it's sheet metal, what exactly is wrong with it? Do you have a leak or it's just the appearance that you don't like? Do you have nail holes or rust holes?

3. What type of shingles do you have? How old is the roof?

Hi, thanks for replying. Ashphalt shingles 5 years old look good, Do not have a leak yet but noticed some rust in the valley, going to get fixed this summer but did not want to reshingle whole roof.

dj1
Re: Roof Valley replacement without reshingling complete roof
dj1

5 year old roof is almost like new.

The normal valley installation follows a sequence like this:
1. 36" wide 30 lb tar paper.
2. Sheet metal, 24" wide. No nailing 9"-10" from the center out.
3. 30 lb tar paper.
4. shingles, no nailing 9" from center out. over a bead of lap cement along the edges of the sheet metal.

If your roof was done like this, you see how difficult it would be to extract the sheet metal valley without tearing up the tar paper on top of it.

You can sand the rusty spots away then paint with rust proof paint or cover the spot with tar and paint the valley, without over spraying the shingles..

John Oosterling
Re: Roof Valley replacement without reshingling complete roof
John Oosterling

Thanks for your information, exactly what I was looking for really appreciate it. John

ed21
Re: Roof Valley replacement without reshingling complete roof
ed21

I would agree with painting. Be sure to use the correct paint if the metal is galvanized especially. I wonder if some of the rust converting products would be good to use before painting. Be sure to get it taken care of before the metal rusts through.
A false economy not to take care of the valleys when re-roofing as you found out. I'm guessing the cheap SOB did it to sell the house. It's not that much more to have it done when re-roofing.

dj1
Re: Roof Valley replacement without reshingling complete roof
dj1

Quote from ed21: "guessing the cheap SOB did it to sell the house. It's not that much more to have it done when re-roofing."

You got that right.

keith3267
Re: Roof Valley replacement without reshingling complete roof
keith3267

I agree with painting the valley before it starts to leak. If the flashing is galvanized steel, then I would suggest the following. Clean the whole valley with a degreaser and let dry completely. Sand to bare metal only where there is rust. Do not damage any protective coating that is still working. Treat the bare metal with a phosphoric acid product like Por15 rust converter. This makes an Iron Phosphide coating that is very effective in preventing future rust. Dry the area with a heat gun or hair blow drier. As soon as it is dry, use a zinc rich primer like a Zinc Chromate on the repaired areas. Then coat the whole valley with a primer and follow with a coat of paint to match the shingles.

If you accidently sand a hole in the flashing, complete the steps through the zinc chromate. Then use a metal filler like JB Weld to fill the hole. Then prime and paint.

Edit: use a spray can for the zinc chromate, but a brush and/or roller and tray are OK for the final coat of primer and paint. You can work a little paint under the edges of the shingles with a brush.

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