I&W Shield

shopman

Most spec sheets say you should apply I&W sheild 24" up the roof past the interior wall. I have a 5/12 pitch roof with a 2' overhang, this would require two layers up from the eaves of I&W shield.

My question is should I specify that 2 layers up the roof from the eave (approx 5.5ft) be I&W shield or can I just have 3' up from the eave? I live in southern maryland and our winters are pretty mild around here, I assume the 24" past interior wall is meant for areas where they get extreme winters. My current roof is 32 years old and there is no damage from inside the attic on the plywood around the eaves from water, and I dont think it currently has any I&W sheild protection.

red_cedar

The 2 feet would be a minimum.
There are many, roofs as yours that have never had a problem.
The I & W is like buying insurance. It is there just in case you need it.
In its use, I try to sperate the ice and water shield from the gutter ( put behind gutter )
My reasoning for this is that if one every has to alter/replace the gutter, one can do so and not compromise the I & W.

jmorgan

Red Cedar is right.
Jim

Grumpy

I install ice shield with a 3' roll, 6' or 9'. I don't cut rolls since it doesnt make monetary sence. I always want the ice shield to be 1.5' past the exterior wall, but 2' is ideal. Obviously the more the merrier.

The way the codes are written in my area, the ice shield must start at the overhang and extend past the warm wall, meaning I can't just slap down ice shield starting at the exterior wall, and cover the over hang with felt.

Therefore if I have a 2' overhang on a 5/12 roof I need to install 6' of ice shield. If I had a 1' overhang this would be border line and I'd try to talk the customer into the extra course of ice shield. Really the cost difference is minimal IMO between ice shield and felt.

I do the opposite of Red, and I wrap the ice shield into the gutter, or if we are repalcing the gutters, they are obviously installed after the roof is done, in which case I leave the ice shield loose 2-3" over the edge of the roof. Then I instruct my gutter crew to wrap the ice shield into the gutter before installing the flashing and brackets.

RooferJim

our jobs are always six feet at eaves as well as at gables,vallies and flashing areas. if its a 4-12 or under then the whole thing, and right on the ocean the whole thing.

RooferJim

J Bennette Roofing dot com

Massachusetts

AaronB.

I do it like red, when possible, behind the gutter. This way, ice cannot back up under the ice shield and into the eave. This is the same way I do my modified bitumen gutter detail.

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shopman

You say you put is 2' past the warm wall, like the instructions say. Do you think this needs to be done for all climates? If we get 3 snowfalls (3" to 6" ) a year we are lucky. It never really gets too cold here. So far by your comments I will have 6' on the roof, but just curious if you think this rule should apply for all climates.

AaronB.

I do not think any rule is good for all climates and/or situations.

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MJW

I understand the idea of wrapping the iceshield into the guttters if there is no roof edge. Don't you guys use roof edge?

When not using roof edge and it is installed by the sider, I leave it hang over 1&1/2". On some houses though the dumbo sider cut the iceshield off at the edge of the roof. The GC will have to deal with that.

AaronB.

Hmmm OK..here it is...IWS behind gutter wrapped down onto fascia, gutter apron installed, roofing is then installed, gutter is installed next.

What exactly is "roof edge"?

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MJW

It's metal, I use steel, drip edge. Goes along all edges of the roof including gables and the metal fascia is put up under it. Most of it is called style "D" drip edge. For gutters we use gutter flashing. Same concept, except it is just a "L" shaped piece of metal.

gutrman

Is there any way you gentlemen can take pics and show me how you are running this behind the gutter. From what I gather this stuff sticks to the roof and water and ice can not get under it?. So you would put this on top of the drip edge. Would it be alright to cut it off even at the edge of the drip edge? If ice and water ever gets that high it should not get under the I & W Sheild because it is sealed tight, not allowing water to get underneath, correct?

I would not place the sheild behing the gutter. You are just creating an avenue for water to flow and not reach the gutter.

I hope this makes sense.

Be gentle. I may be mis-understanding all of this.

bergenbldr

Wraping the i/w behind the gutter is the standard pratice in northern new jersey,however travel an hour north to upstate ny and gutters become rare, here you most likely will see the i/w terminated to some sort flashing that wraps the roof edge.

747

I don't understand. How can you wrap behind the gutters If on my house behind the gutters is fascia wrapped in white aluminum. Wouldn't you have to take that off first then wrap then put it back on?

AaronB.

Nope, I would go onto the aluminum.

I have made repairs tpo homes with IWS terminated at the roof edge, and ice backed up in the gutter, grew into theeave under the apron and over the fascia, ran along the eave to the wall, melted, and showed up at the ceiling inside.

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red_cedar

Aaron is right. the I&W terminated at the deck edge leaves room for ice to back up into the gap.
Lapped onto the aluminum is best when possible.
The application I use when possible, is to lap I&W onto fascia, then felt paper covers that and extends into gutter. Gutter flashing then is applied

In cases of no I&W the felt gets lapped into gutter, then gutter flashing.

Sometimes I think I go thru too much trouble.
Common pratice in the immediate area is to put the I&W just to the roof edge. Also common pratice is no house wrap on attic ( cold) areas of house.
I dissagree with many of the common pratices here, I dont even work close to here.

MJW

It would be much easier to install the gutter flashing first and adhere the I&W to it, and it would do the same thing. Most I&W instructions on the box, say to apply it on top of the metal drip edge.

Now the next thing is replacing this I&W. Have done it a few times, but most don't want to pay to replace sheathing. Often times add another layer on top of it and the inspectors are fine with it. They always specify to put the drip edge on first though.

Grumpy

When I installed gutters, when I just started in this industry, I hated it when the gutter flashing was installed first for two reasons. First it was a PIA to remove when the roofers nailed it in, quite often we'd breake the first course of shingles on accident. Second when installing, having the apron installed first messes up the pitch adjustments the gutter installer needs to make.

red_cedar

the pitch for gutters is something like a 1/4 inch per 20 ft. With aluminum gutters, it could be less than that. Most gutter applications are pretty lousy, installed to last 20 yrs or less before the brackets come out and the corners leak. Quality to some, is marginal for others. But we live in a society of things not holding up

AaronB.

If you install the apron, then the IWS on top of it, you are left vulnerable in the gap to ice infiltration and backup into the eave.

I have never found the need to raise any end of a gutter above the level of the roof, so the apron going on first is a non-issue. I have seen it done, and always think "What were they thinking?"

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