# Roofing Question



## BamaPPC (May 7, 2012)

I'll preface this by saying: I AM NOT A PROFESSIONAL ROOFER.

But, in my youth, I worked as part of a crew that put on a roof or two, metal, roll, and asphalt shingle. So I've seen how a roof goes together.

Today I was just surfing around the internet looking for things pertaining to a job I'm bidding. It's an outbuilding roof that needs replacing. It's asphalt shingle. I was figuring up the squares I was going to need and I remeber a square as being 9 feet by 9 feet or 81 sqft of coverage. But, it's really been awhile since I had learned that bit of trivia. So, just being curious and thorough, and to be sure they hadn't down sized shingles. I went on a hunt. I came across an article on ehow.com about putting on a shingle roof. As part of the instructions it says :

"_Place and lay out the roofing felt over the plywood boards that form the first layer of the house’s roof. The boards are placed and nailed down by the carpenters who worked on the house, so you need not concern yourself with this layer. When putting the felt down remember that this is meant to be a waterproof seal on the roof. Lay the felt down one roll at a time. They should be in vertical rows from the apex of the roof down to its edge; the sides of each row should overlap slightly. Nail the sides of one row firmly into place before moving onto the next until the entire room is covered."_

There a part of that instruction that goes against the way I've seen it done, and always done it. 

*They should be in vertical rows from the apex of the roof down to its edge;* 

Anybody else do it this way? And if so, why? I've always rolled the felt out horizontal, starting at the eave working up to the peak. With each row overlapping the one beneath. Thus giving a shield that runs down the roof and can shed water even if the shingle becomes damaged. 

Running it verticle would also seem to be dangerous. Since you are at the eave cutting off a heavy roll of felt so many times. And having to control the roll all the way down so many times.

Look forward to seeing the responses.


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## Tom Stuble (Sep 17, 2012)

a square in my neck of the woods is 100 sq ft,no matter how you measure it


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## BamaPPC (May 7, 2012)

Thanks Tom. I realize that's how a square is measured today. But, the old man that taught me (geez, has it been that long) 35 years ago. Always said a square was 9ft x 9ft coverage. things change I guess. Back then, maybe he never wanted to be short of shingles on the job. 

Doesn't matter because - that wasn't the question I asked.


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## Tom Stuble (Sep 17, 2012)

i care not for questions


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## Guest (Jul 28, 2012)

Tom Struble said:


> i care not for questions


:laughing: Thanks Tom, I needed the laugh --- Want to know what is even funnier - it is actually seeing how many "roofers" do that around here

Bama - review the manufacturers directions, it is all covered there including coverage, starter strips, ridge caps, etc...


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## Guest (Jul 28, 2012)

The measurement of a square has never changed. Lol
Felt goes from side to side brother.


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## Guest (Jul 28, 2012)

Never heard of the felt going from top to bottom. :blink: This is a case of trusting the first thing you come to on the net. Don't worry, it has caught all of us at one time or another.

However, if you honestly are questioning that method and had any thought that it might be correct, call a roofer to deal with this job. 

On the other hand, if you were just wondering WTF the guy on that site was thinking, then go right ahead and roof it. What's the worst that could happen?


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## Tom Stuble (Sep 17, 2012)

he will over order by about 20 percent:thumbup:


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## SwiftRes (Apr 12, 2012)

Or, make 20% more on the job :thumbup:



Tom Struble said:


> he will over order by about 20 percent:thumbup:


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## BamaPPC (May 7, 2012)

VinylHanger said:


> Never heard of the felt going from top to bottom. :blink: This is a case of trusting the first thing you come to on the net. Don't worry, it has caught all of us at one time or another.
> 
> However, if you honestly are questioning that method and had any thought that it might be correct, call a roofer to deal with this job.
> 
> On the other hand, if you were just wondering WTF the guy on that site was thinking, then go right ahead and roof it. What's the worst that could happen?


LMAO, funny. It was more of a WTH? Never heard of it being done that way...just wanted to see if I was so far behind the times that there was a new way of doing it. I can tell you if I am to put down felt, it's going horizontal.

And, that old man, just may have been accounting for ridge caps, starter courses, and waste. Figuring it at 9x9 gave him the extra shingle to complete the job. I couldn't tell you for sure. And he's been dead for years, so the mystery is lost. And probably wasn't ever relevant. I know the square foot coverage wasn't relevant to my question.


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## SwiftRes (Apr 12, 2012)

At least they are telling you to use felt paper. When I roofed my house/garage a couple years ago, my garage was leaking in several spots, house wasn't, but shingles looked the same. For whatever reason they didn't use felt paper on my detached garage, only on my house. I can't imagine it really saved much cost. House was built in the '70s.


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## Guest (Jul 28, 2012)

Believe it or not,the first builder I worked for ran his
felt this way.
His reasoning,since the roof may not get done right away,and
we always ran 1"x2" furring over the laps,was so rain would
run off and not get dammed up and seep in through the nail
penetrations.
That was 40 years ago,and haven't seen it done that way ever again.


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## BamaPPC (May 7, 2012)

OK you spurred the curiosity in me. So I went looking again. There are two sizes of shingle. Standard 12x36, and metric 13-1/4x39-38.

Pretty sure the old man used standard. So, here's some math.
With a 5" exposure, and 29 shingles to a bundle (3 bundles to a square)

I get this. 3 wide = 9 feet wide. 28 shingles high = 140 inches. 
140 inches divided by 12 = 11.666 feet. that a total of 105 sq feet.
Before you ask, I used 28 shingles because the first one goes down as a starter strip and is covered by the first row, negating it's coverage.

From there, I guess I'd need a degree in mathematics to figure the waste you cut off hanging over the edge, and just how much of that waste could be used as rigde cap. Or if it's even worth trying to reuse the waste as ridge cap.

So, the old man may have been wrong about the actual coverage of a square. But maybe, he was figuring "ACTUAL" useful coverage of three bundles of shingles. And, then again, maybe he was just a crazy old man who knew how to get some extra shingles for the next job paid for by the last sucker.:laughing:


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## Guest (Jul 28, 2012)

Actual coverage of one square of shingles is 98.4 sq ft, assuming no cut offs.


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## Guest (Jul 28, 2012)

BamBamm5144 said:


> Actual coverage of one square of shingles is 98.4 sq ft, assuming no cut offs.


No wonder I am always 1.6 percent short. Dang it. :laughing:


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## Guest (Jul 29, 2012)

Bama-
The most important thing to remember when roofing is to _think like water_. Think of lapping your felt horizontal vs. vertical. Now imagine standing at the ridge with a garden hose running...which will see the more likelihood of water penetrating the seams?


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## BamaPPC (May 7, 2012)

I'm not sure, but I guess I've been misunderstood.

The question was, does anybody else run their felt vertical?

While I do appreciate all the coverage information and advice on how to install as being helpful, it was unnecessary. My question was generated by curiosity about a way to install felt that I'd never used.

As I stated, I am not a roofer. I have a roofer that works for me. I can figure a job and bid it. And to date haven't lost any money on a job I've bid. I leave the hot work to the man that does it for a living.

Thanks for the responses and the information.


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## Tom Stuble (Sep 17, 2012)

no it wasn't unnecessary your statement of what a sq was was wrong,now what if some young guy wondering about roofing thought that was right?

your other question poses the question why are you reading ehow or whatever to learn how shingle roofs are applied

and its been answered,no one misunderstood you..understand?


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## Tom Stuble (Sep 17, 2012)

not to mention now you can actually figure a roof measurement..priceless


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## Guest (Jul 31, 2012)

Maybe you confused a sq with a yard of concrete? 9x9 4" thick is 1yrd.


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