# Ice and Water over Felt on Entire Roof?



## MarkShelby

I have a customer that wants ice and water barrier over the whole roof. I explained that I thought it was overkill, especially on their 9/12 pitch but they want it for extra security. I've never done a whole roof like that. Since old shingles tend to stick to the barrier when you tear them out and leave a rough surface, would putting down a layer of felt underneath of the barrier first be an option? I've never heard of anyone doing that and can't find any examples on the Internet. I'm thinking that way when the shingles stick to the barrier, it would still be easy to get them off by just tearing through or cutting the whole shingle, barrier and felt sandwich. It seems like it should still create a watertight system. Other than the expense, does anyone think there would be other downsides? Anyone think it would wrinkle up and telegraph through the shingles? Or is this just a bad/risky idea all the way around?


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## MarkShelby

I found a relevant thread at http://www.diychatroom.com/f9/removing-ice-water-shield-re-roof-56823/ Someone there makes a good point about water trapped behind the Ice and water barrier having no way to evaporate and rotting the deck.


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## llmotoll

no need for felt if you ice & water the entire roof area. Will be no issues of water being trapped.
Installing ice&water over felt doesn't make any sense. That could cause wrinkling and telegraphing.


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## llmotoll

just read a snippet from the linked topic..
if you do use IWS under entire roof then the high temp underlayments like whats used under metal roofing would help with shingles wanting to stick to it


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## supershingler

I agree. Laying felt and installing ice and water on top of the felt makes zero sense. Felt over the ice and water, yes. Depending on the type of ice/water use, you may never get the shingles removed if you get to be so lucky as to reroof the thing in 20 yrs.


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## Joetheroofer

With a 9/12 pitch you'd really have to screw something up to have leaks..

If he's in a freeze zone, you could run two courses along the eave (70") up to make sure ice dams don't penetrate the roof deck.

You might have some moisture/heat&cooling issues causing more ice dams if you cover the entire roof as all Ice & Water shield is considered a moisture barrier. 

I'd suggest going with a 30# equivalent synthetic underlayment, ice and water shield and run it up the sidewall(if any) by removing siding and such and installing the appropriate metal flashing over that. Don't expose any nails or nail too close to drain lines and you should be good to go.:thumbup:


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## eliteroofing

*be careful*

Don't try to figure out if and how to do this. Instead go back and tell them that you are an expert on roofing and putting IWB on entire roof is a bad idea as it is not designed for that and it will cause problems. Tell them that the roof installed properly by you will not leak and they need to trust you.

Jesse
Elite Roofing NW Seattle


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## soreback

I'm installing full IWB with DuPont RoofLiner over the top of the entire roof, then Malarkey Legacy's 6 nailed and manually tabbed. I'm in a 130mph wind zone, about 100' above the ocean, exposed for several miles 180 degrees. It rains sideways often. I feel ok about it.


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## roofermann

soreback said:


> I'm installing full IWB with DuPont RoofLiner over the top of the entire roof, then Malarkey Legacy's 6 nailed and manually tabbed. I'm in a 130mph wind zone, about 100' above the ocean, exposed for several miles 180 degrees. It rains sideways often. I feel ok about it.


Whowever roofs it next won't feel ok when they have to re-sheath it.:thumbup:


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## RoofCommander

*Ice and Water Shield*

I agree with the majority here. Putting IWS on the entire roof is not a good idea. Instead, maybe tell them you would do the valleys with IWS, which makes more sense in my opinion. :thumbup: Not to mention, it's common practice now in certain parts of the country.

~Brandon

Roof Commander, Inc.
121 S Orange Ave #1502
Orlando, FL 32801
(407) 956-4267


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## gavelgeneralroofing

MarkShelby said:


> I have a customer that wants ice and water barrier over the whole roof. I explained that I thought it was overkill, especially on their 9/12 pitch but they want it for extra security. I've never done a whole roof like that. Since old shingles tend to stick to the barrier when you tear them out and leave a rough surface, would putting down a layer of felt underneath of the barrier first be an option? I've never heard of anyone doing that and can't find any examples on the Internet. I'm thinking that way when the shingles stick to the barrier, it would still be easy to get them off by just tearing through or cutting the whole shingle, barrier and felt sandwich. It seems like it should still create a watertight system. Other than the expense, does anyone think there would be other downsides? Anyone think it would wrinkle up and telegraph through the shingles? Or is this just a bad/risky idea all the way around?


 Full ice and water on 912 is pointless. Get them to upgrade to deck armor or titanium.. Just ensure its there for pitch changes of 5 or more especially if they push for non ribbed open valleys..

Likely have some salesmen feeding them bullshit so at least talk them into worthwhile install lol


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## johnmeto

Depending on the type of ice/water use, you may never get the shingles removed.


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## Dobsonluke

Always ice and water first, it'll be one leak proof 9\12, next crew will probably have to resheet plywood to get it off lol and complete ice and water is not completely pointless, take into consideration trees and moisture around the area, it might just be the thing that saves the roof in 30 years, the costumers always right also if he wants to do it, warn him but can't stop em


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## Merge

IWS on the entire roof is not a good idea


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