# Low slope I&W



## katoman (Apr 26, 2009)

My own home is a 5/12 pitch with an addition on one side which is a 2 1/2/12 pitch. Low slope.

In the winter the ice gets up under the shingles and leaks in. So I'm going to strip it and install rolled roofing. 

I need to shovel this off in the winter, and I'm wrecking the shingles.

Two questions - would you cover the whole low slope roof with I&W shield, and, would you run the rolled roofing horizontal or vertical?

Thanks for your expert opinions.


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## Tom M (Jan 3, 2007)

You shouldn't need the ice shield if you do a roll maybe half lap the glass base sheet. I would never do verticle


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## griz (Nov 26, 2009)

Kato, Just for piece of mind I would put on the I&W shield.
Install your rolled roofing horizontally, at least 6" lap and seal the laps also. Anyone do old fashioned hot mop up there?


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## katoman (Apr 26, 2009)

No hot mop. I'll do it myself, I am a licenced shingler (shingles only)

I am thinking to ice and water one row as starter, and one row where the two roofs join. 

I've heard not to do the whole roof since you may get condensation problems.

I agree with the horizontal install, although it can be done either way.

I'm interested in other's expert opinions, as I have not done this particular application before - that is going onto the low slope.


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## jmiller (May 14, 2010)

Rolled roofing is not for roofing anymore...

Skip the Ice/Water and install Certainteed Flintlastic Self Adhered Modified Bitumen with the granulated surface to match your shingles.


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## katoman (Apr 26, 2009)

jmiller said:


> Rolled roofing is not for roofing anymore...
> 
> Skip the Ice/Water and install Certainteed Flintlastic Self Adhered Modified Bitumen with the granulated surface to match your shingles.


Thanks, I went to their site. This is a two ply system, I did a roof like that years ago. It was expensive.

Barring that, could you give me your recommendation as to what specific base sheet and cap sheet you would use?

Thanks


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## BamBamm5144 (Jul 12, 2008)

Whats the reasoning behind deciding to go with rolled roofing?

If I were you, I would ice and water the areas you are already considering and install a dimensional shingle. In the winter, install some heater cables and you shouldnt have to worry about raking any snow off.


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## OldNBroken (Feb 8, 2008)

jmiller said:


> Rolled roofing is not for roofing anymore...
> 
> Skip the Ice/Water and install Certainteed Flintlastic Self Adhered Modified Bitumen with the granulated surface to match your shingles.


100% agree w/ jmiller. You can do it with nailable base and capsheet (two-ply) or base, midply and cap (3-ply)

I'm just wondering what's more expensive to you? Installing a system designed exactly for what you have and being satisfied (flintlastic). Or piece-mealing ice/water and capsheet together that will fail in a few years and you'll be right back here? Just asking.

It's much much easier to do things right the first time.


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## katoman (Apr 26, 2009)

BamBamm5144 said:


> Whats the reasoning behind deciding to go with rolled roofing?
> 
> If I were you, I would ice and water the areas you are already considering and install a dimensional shingle. In the winter, install some heater cables and you shouldnt have to worry about raking any snow off.


The snow here can be 4' deep on this roof. I have to shovel it after every major snow storm, and it's ruining the shingles. It's a low slope, the heater cable won't work.


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## SLSTech (Sep 13, 2008)

katoman said:


> I am thinking to ice and water one row as starter, and one row where the two roofs join.
> 
> I've heard not to do the whole roof since you may get condensation problems.


I have never heard of that issue unless it is improperly vented or they tried doing a hot roof system & completely botched the job. The only real issue with I&W besides the cost, is when you go to replace the roof -almost impossible to scrape off fully

Tar Paper & I&W are both highly impermeable to water & vapor so the issue would be the same, except for one hasn't sealed around the nails as well

I&W the whole thing followed up by either metal roofing or shingles


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## katoman (Apr 26, 2009)

I'm jogging my memory on the roof I did with the two ply system. It was a superior product/install than a regular rolled roof.

I'll check out pricing on it and probably go that route.

Thanks to all for your input. I had forgotten about the two ply system.

Must be getting senile :laughing:


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## jmiller (May 14, 2010)

If you're really worried about ice dams there is a self adhered base sheet that the SA cap can be placed on. That would keep anything frozen from creeping under.


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## katoman (Apr 26, 2009)

jmiller said:


> If you're really worried about ice dams there is a self adhered base sheet that the SA cap can be placed on. That would keep anything frozen from creeping under.


Yes, that was the install on that roof I did. I'll research the available products and get the right one.

Thanks again


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## Cjeff (Dec 14, 2009)

I used I & W (IKO) on a 2/12 roof with shingles over. It leaked :shutup:
I went back up and tared the I & W to the roof at the bottom, the shingles at the bottom to the I & W. It still leaked. I tared the joints between the shingles and the nail heads. No more leaks:clap:

Now I do all the taring as I install right from the start.


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## Tom Struble (Mar 2, 2007)

i&w dosn't change the pitch requirement for shingles..does it?


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## SLSTech (Sep 13, 2008)

tomstruble said:


> i&w dosn't change the pitch requirement for shingles..does it?


Low slopes can be done with double felt in many area's (some area's may run into issues with BI's) - I&W would qualify as 2 layers of felt

Directions from Owen Corning's


> *
> For Low Slope Decks – 2" in 12" to less than 4" in 12"​*Application of underlayment, metal drip edges and eaves flashing:​*(A)​*​​​​Apply 19" starter strip of underlayment over metal drip edge at
> eaves. Use only enough fasteners to hold in place.​
> *(B)​*​​​​Use 36" strip of underlayment for remaining courses, overlapping
> ...


Tamko Directions 


> *
> 6. LOW SLOPE APPLICATION
> *On pitches 2 in. per foot to 4 in. per foot cover the deck with two layers of asphalt saturated felt. Begin by applying the felt in a 19 in. wide strip along the eaves and overhanging the drip edge by 1/4 to 3/4 in. Place a full 36 in. wide sheet over the 19 in. wide starter piece, completely overlapping it. All succeeding courses will be positioned to overlap the preceding course by 19 in. If winter temperatures average 25°F or less, thoroughly cement the felts to each other with TAM-PRO or TAMKO Plastic Roof Cement from eaves and rakes to a point of a least 24 in. inside the interior wall line of the building. As an alternative, TAMKO’s Moisture Guard Plus® self-adhering waterproofing underlayment may be used in lieu of the cemented felts.


I could go on, but basically they all support it & use similiar systems


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## Morning Wood (Jan 12, 2008)

Just because code says 2:12 pitch with asphalt shingles is ok, doesn't mean that it is ok. My opinion.


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## Tom M (Jan 3, 2007)

but it works.......I ve done some with 1/2 lap paper and ice shield and shorter shingle exposure on 2on 12s. 10 years plus no leaks.


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## neolitic (Apr 20, 2006)

tom m said:


> but it works.......I ve done some with 1/2 lap paper and ice shield and shorter shingle exposure on 2on 12s. 10 years plus no leaks.


Tell me about those valleys?


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## Morning Wood (Jan 12, 2008)

IMHO only thing that should be on a roof in a conditioned building with 2:12 or less pitch is rubber or double locked standing seam metal roof. But, if I were forced to install asphalt on that kind of pitch I think it would be ice and water the whole roof. I might even go over the ice and water with double coverage triflex. Why? I don't know. I'd also be tempted to tar every nail head. which would suck such big time I don't even want to think about it.


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