Ice and water shield in valleys only?

I have noticed that the roofs being replaced primarily due to insurance claims in the area all the contractors typically are putting ice and water shield only in the valleys only (not on the eaves); the insurance scope does not call for any ice and water and I am guessing this is cheap insurance for the installers. Just curious if this is typical practice?

The practice of when and where to install waterproof membranes, such as Ice and water, is dictated firstly by local building code requirements and secondly by contractor preference. You will get plenty of answers here based on the preference of the installer, but what you need to know before you can fairly criticize, is whether it is indeed required. For that, it would be helpful if you specify your general locale and then someone who works in your region might chime in on what the minimum requirements are.

Yes, the reason is it is cheaper than valley metal and it is accepted.
I dont like it but most seem to be doing it.

If you don’t have snow and ice dams then you don’t necessarily need ice and water on the eaves. Valleys it makes more sense to always do so for an extra layer or protection should there be a leak in the valley.

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We 2 ply the underlayment in the valley
Then we install 26 g valley metal.
Then we roofing cement both sides of the valley metal before we shingle it.
Its not required, but that is what we do extra.

Thanks for the replies.

Makes sense. I am in NC and I was just curious since most contractors do the valleys only but I read on one contractor’s website they also do the eaves. We do get some snow but nothing like up north.

I already had a leak in a valley towards the eave…ice and water supposedly done correctly (reference my other post, still dealing with the water damage a month later). Apparently the cool weather did not allow shingles to seal and a small amount of snow we got backed up water in the valley (what I was told). It was corrected by adding a sandwich of ice and water and flashing along with changing the weave in that valley to a California cut…

I used to run 24" aluminum, 18" 90#upside down, then 36" 90# right side up, and double cut the valleys.

IWS in valley’s is code. In NC, code does not require it on the eaves. Valley metal or Rolled Roofing may also be installed in the valleys to comply with code.

That is how we did it when I first started.

There are a few of those 30 year old roofs still in service!

Different building codes in different parts of the country, pretty surprising what’s required in Reno and what’s required in Cody which are two fairly similar in weather conditions. More snow in one place, colder for longer ih the other. Some places say one course of ice dam on the eaves which makes no sense Ito me if it isn’t going above the plate line of the building…Valley’s only makes just about as much sense, if the water is going to crawl all the way up a valley why isn’t it going to crawl up the eave?

Code is 2’ past the interior wall on the eave.

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I know that, that’s what it was in Reno but here in wy. they only require it in the valley’s and when they do require it on the eaves they only require one course of ice dam, I don’t think they realize how ice damming works

Depends upon the codebook they’ve adopted.

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That’s not entirely correct even for Wyoming. I understand that Wyoming hasnt changed code requirements since the 1989 model energy code and it’s different from jurisdictions on what’s required however most jurisdictions that have minimum compliance requirements follow the 2018 IBC, and does require ice and water on the eave to extend no less than 24 inches beyond the inside wall so it’s going to depend on the overhang whether or not additional courses are needed. Again that’s been my experience in those areas of Wyoming that have adopted code standards

Pretty sure I know what’s required in the “JURISDICTIONS” I’m working in and there are other requirements in other counties, but wouldn’t you think there would be some sort of uniform code throughout an area. 2ft past the plate line on the level thats the way I’ve always understood it. Not sure if they changed anything in recent years but Reno’s ice dam requirements use to only come into play depending on the elevation @ the job site

I wasn’t in any way being short with you but I noticed that you mentioned Cody as one of the locations you were working in. November 2018 the city if Cody adopted the 2018 residential code and does require additional ice and water if one course doesn’t give you the minimum requirement of 24 inches beyond the exterior wall. That’s all I was saying but I’m certain on that for the city if Cody because I have a copy of the ordinance where it was adopted. I don’t necessarily agree with how they chose to handle building code requirements on the state level but I see it where I am all the time as well. Code requirements are the minimum standard anyway. Compliance is where the real issue is because requirements don’t really matter if nobody is going to actually enforce the standards they choose to follow. I do think it would be less headache for something standard across the nation but until compliance is taken more seriously it’s not going to really make a difference in the rural areas.

If the municipalities would actually send an inspector out when you call them it would probably help to get people to conform to whatever rules they choose to adopt. As far as the outlying areas where there are no inspections,who knows. If you’re a good contractor you are going to bring this up to you’re customer so they are aware. In Cal. and Nev. if you are not compliant with a building code you are probably not going to be doing whatever it is you’re doing for any length of time

I couldn’t agree More however on that same note, but as long as we do what’s right with our customers and provide the same quality as we would expect for our own homes exceeding the basic minimum it will not matter what state where we work.


Very true, but when you’re losing jobs for doing the right thing that kind of sucks