Please post questions about anything having to do with roofing

[iniquette]

What is sheathing?



Kidding, this is a good thread you started though Kenton. keep up the good work.

[Kenton H. Shepard, CMI]

Originally Posted by bgromicko

Kenton,

I've come to learn that re-roofing over an existing layer of composition shingles, while generally permitted by code, reduces the ability of the newer shingles to resist impact damage from hail. Therefore, in hail-prone regions the insurance industry recommends and local code may require that re-roofing should include removal of the existing layer(s) of old composition shingle roofing.

Correct?

I dug a little deeper and edited my last post. I'm not sure about code, but shingle manufacturer's will be worried about having to back up their warranties, so they will typically limit the substrates to those that provide good support.

GSF/ELK limits their substrates to pretty much wood decks which comply with their requirements and to asphalt shingles in good condition.

Here's a link to their tech page in this subject.

By the way, they have a great set of tech papers available online.

[Frank Albert]

"I'm not sure about code, but shingle manufacturer's will be worried about having to back up their warranties, so they will typically limit the substrates to those that provide good support."
Nailed to spec, at the exposure, the shingle get cracks when nailing them. The nail forces the shingle into a sharp bend/crease there. Tends to leak and void warranty.
Nailed higher than 1" above the exposure causes the shingles to slide down the roof, which creates leaks. And the high nailing also voids warranty.
Other than that, no issues I can see.

[Dennis R. Goudreau]

what is the # 1 cause for shingle failure

[Kenton H. Shepard, CMI]

I've asked a GAF/ELK tech guy and a lead field adjuster for a big insurance company. If one of them doesn't know... I don't know who would.

Some kinds of things manufacturers don't like to discuss much. I've been unable to get time lapse photos showing how shingles change as they age.

[Shawn Rowe]

Thanks for your help Kenton! Are there any manufacturers that would prohibit or void a the warranty for this installation. The shingles were obviously not cut properly and is very unsightly but does it affect performance?

[Kenton H. Shepard, CMI]

Originally Posted by srowe

Thanks for your help Kenton! Are there any manufacturers that would prohibit or void a the warranty for this installation. The shingles were obviously not cut properly and is very unsightly but does it affect performance?

Sorry Shawn, I can't really tell from the photo. It looks like shingles don't align at the valley, but the pitches might be different or the exposures might be incorrect. You'd need to check what substrate they're installed over, lift a few tabs to see if they offset shingle courses correctly, if they're nailed correctly, if they're sealed at the adhesive strip, etc.

You'd want to re-seal any adhesive strip you break during the inspection to avoid liability for repair if they're later blown off due to failure to re-seal properly (a strong possibility this time of year.)

[Kenton H. Shepard, CMI]

Originally Posted by dgoudreau

what is the # 1 cause for shingle failure

Here's the answer from the insurance company expert:

I'll put this in the simplest terms, although every case is different. If
there is something that is causing a leak within the first few years (just
because no one has noticed doesn't mean that it hasn't been leaking) it is
usually installation-related. If the roof wears out prematurely it is
usually manufacturing-related, however, that failure can be hastened by a
faulty design or implementation of the attic ventilation system. The more
heat that is retained in the attic the sooner that shingle will wear out,
regardless of whether there is a manufacturing defect or not. Both good and poor products will last longer of the attic is properly ventilated.

In the most basic terms, you are usually going to know about an install
issue within the first couple years. That's why some residential roofing
companies choose to offer a 10+ year warranty on their labor. People think it means they must be really sure of their work, when in fact the companies just realize that if something was done wrong, 99% of the time it will be identified in the first year or two when it would have been covered under a standard warranty.


From a major shingle manufacturer:

Unfortunately, that information is not available to us.

[William Warner]

Is Ice Guard an adequate substitute for drip edge flashing?

[Kenton H. Shepard, CMI]

Originally Posted by wwarner

Is Ice Guard an adequate substitute for drip edge flashing?

No, but it's better than nothing.

[William Warner]

Originally Posted by kshepard

No, but it's better than nothing.

Like the other side of that house.

[Barry Adair]

Is there a site/link that has a list of approved flashings and appropriate location/installation details

[Larry D. Kage]

Originally Posted by wwarner

Is Ice Guard an adequate substitute for drip edge flashing?

Attachment 26246

That is sad, Bill, for lack of spending a couple hundred dollars for drip edge.

Picture four doesn't even look like ice and water shield.

What quality!

[Marcel R. Cyr]

Originally Posted by badair

Is there a site/link that has a list of approved flashings and appropriate location/installation details

I don't know if this one may help.

Maybe Kenton can use it.

http://www.a-actionhomeinspection.co...0-%20Roofs.pdf

Marcel

[Kenton H. Shepard, CMI]

A lot of sites have a few, or common flashing details.
Architectural Graphic Standards has quite a few. The SMACNA has a lot too, but they both charge for them.
InterNACHI is getting ready to put together a collection of details, including flashing, but two other projects have priority.