# IWS over entire roof?



## Scuba_Dave (Jan 16, 2009)

That's what I did
Some have said that shingles will stick to IW when re-roofing & be a mess to remove
So in some cases the decking then has to be replaced


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## Clutchcargo (Mar 31, 2007)

I've seen them do it that way before on the TV show Holmes on Homes but he's not always right.
As far as the shingles sticking, that sounds like the future home owners problem.
Thanks


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## Scuba_Dave (Jan 16, 2009)

With my skylights it seemed the best choice
And for an extra $60 on the sunroom, maybe $120 on the main roof I figured what the heck
Then the addition......I think 5 rolls of IW - so another $300

Unfortunately I am the future homeowner :laughing:


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## meltdowndave (Apr 6, 2009)

We recently tore off shingles and replaced them with tile.

We used a GAF ICW, but placed it atop 30# felt. We also used a batten system of pressure treated wood. 

The roofer wouldn't do it any other way.

It added several thousand dollars to the cost of the job, but both the roofer and I sleep better at night knowing that there wasn't many, if any, ways to make for a better roof.

Preserving the deck was important to us. Should the tile not work out, we also have the ability to strip off the ICW without needing to replace it. Given that the deck is lovely tongue and groove planking, it looked at good as the day it was nailed down 60 years ago. I can't imagine saying the same of plywood.


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## jogr (Jul 24, 2007)

meltdowndave said:


> We recently tore off shingles and replaced them with tile.
> 
> We used a GAF ICW, but placed it atop 30# felt. We also used a batten system of pressure treated wood.
> 
> ...


Doesn't that void the warranty on the I&W (putting it over felt)?

Plywood will look just like new after decades under a properly shingled roof. I just ripped off the shingles on part of my 34 year old house to tie in my addition and the plywood looked like new other than the roofing nail holes and some black residue from the felt.

I have mixed feelings about I&W. It's suppose to preserve your sheathing and house from water damage (and it does until you reroof) but essentially guarantees you'll have to replace your sheathing when you reroof so it kindof defeats it's own purpose to an extent. For that reason I would never put it over the whole roof since that just about guarantees resheathing the whole thing when you reroof - and who gets ice dams over their whole roof? Use it on the roof where ice dams are a problem and be ready to resheath those areas when you reroof.


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## meltdowndave (Apr 6, 2009)

jogr said:


> Doesn't that void the warranty on the I&W (putting it over felt)?


Never given it any thought until now...

After reading the GAF website the official installation instructions say that it "may" be installed directly to the deck, but doesn't indicate that it's mandatory. 

Regardless, the warranty is 5 years labor and material for a *shingled* roof and then only I&W only cost beyond that. There's no mention of tile.

But back to the topic...

If you have a shallow pitch roof, then a full coating of I&W would defintely be something to look at. Perhaps a direct to deck application in the normal areas and some 15# felt beneath the I&W elsewhere? That would seem to offer a good compromise between protection now and re-roofing costs later?


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## Clutchcargo (Mar 31, 2007)

The roof overhangs on my house have the original 88 year old wood. Wouldn't you think that would get torn up with a re-roof with the IWS on it?


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