At our local Menards, the poly face is $34/sq. (3'x33') and the granular
face is $36/sq. (and that's retail).
As far as labor, it would be only a little more, considering you would have
to roll out and fasten down use 15# underlayment anyway. (At least if your
building to code).
If your only installing cheap asphalt shingle roofs (20 year), I would agree
that it's use may be questionable as the roof is probably only going to be
good for 15 years anyway. But for longer-life products (including 30-40 year
asphalt, tile and the like), it's a no-brainier to use it.
For a quality home, a roof is not a place to go cheap.
And why aren't manufacturers recommending this? They'd sell more
The answer is probably two fold: it has little or no value in
practice, and second, ice and water shield is a vapor barrier, and
unless your ventilation is good, you could wind up with rotted roof
This is not a standard practice. It is not being done in most parts
of the country. Go out and look at some roofs, talk to some roofers
Manufacturers are manufacturing this product, like all products they sell to
a specific market / end use. This product was designed to comply with a
specific code requirement, as an alternate to two layers of underlayment,
cemented together. It saves time and labor; money in other words.
However, that's the code, and most prescriptive codes are designed as
minimums and are usually exceeded when there is a good reason to do so. The
reason that the manufacturers do not state that it is to be used everywhere
is simple, whatever they put on the package is considered a requirement,
legally binding in court. Any local building official would then be
permitted to make a full installation mandatory. As there is no need to
overbuild anything, there is no need to make such practice a recommendation.
You're worng on both points. First it has obovious value in offering
additional protection to a roof deck. Only a fool would argue that overkill
has no value. Second, although it does have a specific requirement of 0.01
perms max. it should never cause a roof deck to rot. (Do you think that
standard Type I underlayment overlaid with two thicknesses of asphault
shingles wont retard the passage of water vapor?) Ventilations in al attics
is a must (and a code requiremtnt). The most likely pace you will every find
a rotted deck is low down, near the eaves. Upon investigation we find that
there was little or no air circulation, often that the insulation had been
blown into the area and in contact with the bottom of the roof deck. Proper
ventialltion, and not just the minimums required by the IRC, is an absolute
must. (It's also off topic).
As an inspector (my current position is plan reviewer), I have inspected
hundreds of installations. I have found that roofers vary in their
knowledge, but those highly concerned with doing an outstanding job that
they can be proud of, to those who are looking forward to collecting their
paycheck and getting drunk that evening. (Like any trade). Some even argues
that they didn't need to use underlayment. Many didn't know the proper way
to build a valley and a few could not explain what a stepped flashing was or
what the requirements for it were.
I do agree that it's not standard practice, as most of the public either has
no idea as to what constitutes a good roof verses an outstanding one; and
they will always opt for the lowest price. It's use is really for those who
are building a higher-end home, usually with permanent clay-tile roofs or
long-life asphalt or the like. For the average low-end market, installing
ice-shield at the eaves with regular Type-I underlayment over the rest of
the roof is the only way to maintain competitively and low price.
This by no means ensures that the owner will be getting the best for his
money (for only a modest amount more he could be getting many more years of
roof life compared to the minimum materials). You simply quote minimum code
to get the job and then offer to upgrade the materials (labor will be pretty
much the same in all cases).
The argument isn't whether is costs more or not (it does) or whether is
common practice or not (it isn't). The argument is that it makes a better
roof (longevity and greater leak resistance, especially in high wind zones)
verses one covered with standard Type-I underlayment. (It does).
whatever they put on the package is considered a requirement,
If this is true, then why do they include hips, ridges, and rakes in
their instructions? Ice and water shield on ridges and rakes is not
code in my state. But you are saying that it is considered a
requirement, legally binding in court because GAF puts it on their
Regarding ventilation, in the case of new construction, you are
probably right. But it is highly irresponsible to be recommending ice
and water shield over the whole roof to everyone. Lots of old houses
have roofs that are marginally ventilated and have marginal vapor
barriers, as you must know.
The thing about buying stuff at Menards/Lowes/Home Depot, etc. is that the
choosing of products is the sole responsibility of the purchaser.
I sort of prefer that myself.
Just yesterday I purchased about $400 worth of PT lumber and anchor bolts
and various other things for a project I'm building and I *hand selcted*
every single component to assure that I received the best they had.
If your roofer spent time fixing tears and stuff you should have planted
your workboot squarely in his ass for wasting your time and resources.
A few minutes spent up front scrutinizing the purchases saves alot of
problems on down the line.
Quality builders know this, why don't you?
If you think that the roof is important, then you should also
consider your plumbing. Although, like placing IWS
everywhere, it is not common practice, placing all of your
plumbing pipes in PVC can keep that possible leak from
becoming a disaster. I have seen many more homes destroyed or
damaged by plumbing leaks than roof leaks. And I should know
as I am in the insurance repair business (15 years or so).
It is simple (like using IWS everywhere). Simply install 2"
PVC pipe everywhere that you need water, then run your copper
or PEX through the PVC. Should there be a leak, the PVC
And hey, what about fire? It would probably be a good idea to
encase all of your combustable materials in concrete. That
way, there is nothing to catch fire except your personal
property and that could be treated with a fire retardant.
Don't forget about these other things and just add ICW.
Remember, a little extra goes a long way to protect your
quality home. Whats a few extra tens of thousands of dollars
when your peace of mind is at stake?
Ya know, if you tack another $10k to the overall price for the
infrastructure and $5k for the schools (do it for the *children*) you'll be
close to describing a typical SW Florida home.
The kind that no one can afford.
As far as I'm concerned they are completely irrelevent.
Here, I'll make this easy for you Larry.
I have been involved in over 7,000 projects in an area with some of the
toughest *builing codes* in the country and ya know what?
I mainly ignore them.
Ya see, when you design large scale custom residences on islands that are
routinely subjected to Cat3 to Cat5 conditions there is no way in hell a
thinking person would trust any stupid assed gov't ruling with their clients
property and lives or their own reputation.
People that tout building codes are silly and not meant to be taken
Ohhhhh Don, you must be the new net super hero. I'm so impressed!
Custom residences yet! Wow! Surely you're the only one in existence which
designs a custom home in the Cat5 territory.
And, a tough guy at that.
Can I please have your autograph?
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.