Asphalt/Comp shingle joint allignment/staggering. - InspectionNews

#1 (**permalink**) 03-07-2008, 04:56 AM

Hey guys, long time no see! Just getting set to go around with a seller/the agents contractor/etc about this and wanted to verify I wasn't crazy.

Each course should offset about 6 inches to the left/right (depending on how your looking at it) from the course above/below to make a stair stepped pattern where the joints align about every 5th course.

The one I looked at the other day staggered them, 6 inches to the left, then the next course six inches back to the right, next course joint was then aligned with the course not below it, but every other course.

Checked the installation instructions and the only mention for the purpose of this is to avoid an unpleasant pattern, but I always thought it was for less probable water penetration. What do you all say and would the latter meet "CODE" where you are?

Rick Cantrell · #2 (**permalink**) 03-07-2008, 05:28 AM

I see no reason why being offset either way would cause any problems.

#3 (**permalink**) 03-07-2008, 06:11 AM

Just got ahold of CertainTeed (The manufacturer) and they said all was well, it would not void the warranty, it would just look funny (which is why it caught my eye I suppose).

FYI

...
I still think the stair step method is more solid.

Jerry Peck · #4 (**permalink**) 03-07-2008, 06:31 AM

By 'joints' I suspect you are referring to the end slots (ends) of standard 3 tab shingles.

The main thing is that the slots between the tabs, which includes the end slot (actually half of a slot) are aligned approximately centered on the tab below and the tab above. Being as the tabs on the standard 3 tab shingle are 12" wide (center of slot to center of slot), that puts the slots 6" in from the center of the slot above and below.

Where the ends of the shingles fall is much less important, i.e., starting off staggering the slots from the rake, or starting off with a full shingle, then half a shingle, then a full shingle; either way offsets the slots by the same 6". That's the critical part.

Jonathan Clevenger · #5 (**permalink**) 03-07-2008, 06:48 AM

Weather you "stairstep" or offset them back and forth, both ways are fine. I always put them down in a stairstep pattern though.

This mostly shows up on roofs that used 3-tab shingles, but the shingles will shrink some over time, and you can see bigger gaps going straight up the roof where they offset the shingles back and forth. Not enough to be any type of problem, but I think it looks bad and unprofessional.

#6 (**permalink**) 03-07-2008, 07:02 AM

Was an architectural shingle install. I've never been part to anything but the stairstep myself, I've seen guys "rack" them with the 3 tab, just never seen it with Landmark 30's. "It does not look right" is right. By joint I was referring to where the two ends of the shingles came together and am I nuts in thinking with water running straight down that creates more of a weak point where the joints are stacked? Isn't this why ur getting rows of curling on some of these? I don't see that nearly as much with stair stepped installs.

Now I get to explain to my client why I was "wrong"

oh well, learn something new everyday.

Jerry Peck · #7 (**permalink**) 03-07-2008, 08:32 AM

Quote:

Originally Posted by Clinton Rushing

By joint I was referring to where the two ends of the shingles came together and am I nuts in thinking with water running straight down that creates more of a weak point where the joints are stacked?

Now I'm confused.

Above, it seems you are stating that the joints are one above the other. Previously, it seemed you were stating the joints had shingle tabs between them from the intermediate course.

?????????

Jonathan Clevenger · #8 (**permalink**) 03-07-2008, 09:36 AM

Jerry, I believe he's worried that with every other joint in line with itself, that it will leak.

If they're installed properly, even the staggered back and forth way, they won't leak. One bad thing with this type of installation is that you need to not nail the end of one shingle so you can slide the shingle beside it underneath. That in itself is not a problem, but a lot of roofers won't bother to lift up that end, and put a nail in the shingle underneath before nailing the top shingle down. So what happens is every other shingle only has 3 nails instead of 4 in it.

Jerry Peck · #9 (**permalink**) 03-07-2008, 12:25 PM

Quote:

Originally Posted by Jonathan Clevenger

Jerry, I believe he's worried that with every other joint in line with itself, that it will leak.

But that's no different than aligning the slots.

Quote:

So what happens is every other shingle only has 3 nails instead of 4 in it.

Or 5 instead of 6 ... except that I've never seen that done. That's only a problem if you rack the roof, if you lay the shingles one after the other across the roof, stagger them on the next course, then lay them across the roof again, then there is nothing covered which needs to be lifted.

The same when the roof is staggered, it's just that instead of staggering one half tab you stagger one half a shingle.

Either way, though, that will not cause it to leak.

Jonathan Clevenger · #10 (**permalink**) 03-07-2008, 12:53 PM

Quote:

Originally Posted by Jerry Peck

That's only a problem if you rack the roof, if you lay the shingles one after the other across the roof, stagger them on the next course, then lay them across the roof again, then there is nothing covered which needs to be lifted.

The same when the roof is staggered, it's just that instead of staggering one half tab you stagger one half a shingle.

Either way, though, that will not cause it to leak.

Working across the roof may be fine, but its just not how things are done. It would take you 3 times as long to do a roof that way.

I've never put down, or seen shingles where they've staggered them a half of a shingle. 3 tabs should be staggered 1/2 of a tab, and dimensionals should be staggared 6-8 inches.

Erby Crofutt · #11 (**permalink**) 03-07-2008, 02:44 PM

What y'all are describing is called the "racking method" of shingle installation. Some manufacturer's allow it and some don't.

Two Ways Of Installing Shingles | Roofing | Reader's Digest

#12 (**permalink**) 03-07-2008, 04:16 PM

http://www.gaf.com/Content/Documents/22850.pdf

Aaron

bruce bjorkstrand · #13 (**permalink**) 10-22-2009, 09:49 PM

I have been installing roofing since 1965 with my father. No I didn't have to walk to school up hill both ways in the winter in Wisconsin BUT I have roofed forever. I was built for speed and what you call racking is fast BUT you can't skip nail every other course of shingle or you have problems. You need to install 4 nails in every shingle, PERIOD! I have never roofed with the staggered system of going across the roof to the end then start over. That takes to much time and nothing is different. You can talk about warranty if you want but I have not found a shingle since the oil embargo that lasted as long as stated on the wrapper. I have been installing metal shingles EXCLUSIVELY for the last 10 years and all on residential roofs. I put my metal roof on 13 years ago and it is still just fine.

Dave Belisle · #14 (**permalink**) 10-23-2009, 03:00 AM

I saw this roof this fall in Alaska..... Not sure what they did here , but this building was right next to a bar....

Dave in NH

Dave Belisle · #15 (**permalink**) 10-23-2009, 03:15 AM

I will try again....

Dave in Nh

Jerry Peck · #16 (**permalink**) 10-23-2009, 06:25 PM

Quote:

Originally Posted by Dave Belisle

Not sure what they did here

Dave,

I'm guessing that the other end looked the same, only reversed.

That roof is no longer "square" as in "rectangular", but is now likely a "parallelogram".

Mike Schulz · #17 (**permalink**) 10-24-2009, 04:19 PM

Vertical was our preferred method because it was much easier on steep sloped roofs using toe boards etc. In Texas in 84 they would only allow 5" inch stagger which they claim was for wind resistance. The only way to install was stepped. It left a cool looking pattern though. The key slots went diagonal up the roof then the normal straight up and down.

If you use the stepped method you could basically lay down the roof with no by-lines. They just seemed to run straight. On racked we pop 10" lines (horizontal) and 29"/35" tape hooked off the rake for by-lines (vertical).