Low slope roof

Generally, you just reduce the exposure on lower sloped 3-tab shingle roofs.

I have read and reread all of the suggestions re:the 2.5 x 12 pitched roof and my head is spinning. The general consensus seems to be not to use shingles.But,then,there is the debate over 3 tab vs. architectural. I have presented this to my potential roofer and he still emphatically sticks by Tamko’s specs that indicate 2.5 is fine for shingles. He has also pointed out that GAF and others specs indicate such, as well. He would be covering the area with Grace ice/water shield. He is pricier by 500.00 than the other roofer who wants to place the Liberty base and cap on the roof. BUT #1 doesn’t use a power nail gun and I know that a lot of you don’t agree with that at all! Thanks for all of your advice.

Hi all, I am new to this site but was looking through some of your comments. Not to take anything away from the person that originally posted this topic, but my situation is very similar. I just need a good honest opinion here.

I live in San Antonio so we don’t get that much rain, but we do get our share. However, this is what I have…

I just built a 17x42’ addition with a 2.25/12 pitch roof. I used #15 tar paper and overlapped it per the directions. I used 20 year Owens Corning “classic” shingles, which clearly stated that they were good for 2/12 pitch and up. So, as far as the installation instructions, the shingles are good to go.

Now, this is my delimma. I have the ENTIRE roof done, and now I read that maybe I should have used roll roofing or a #30 tar paper underneath. If I don’t have any leaks so far, do I really need to do anything? Just like everyone else, I am working on a budget, so I really do not want to tear the entire roof off and start all over again.

If you can offer anysuggestions, please let me know. Like I said, everything is flashed correctly, the shingles are done and it is currently NOT leaking. It was leaking before, but it was because my flashing wasn’t done correctly.

Thanks in advance!!!

Mike
San Antonio, TX

[quote=“psychomti”]Hi all, I am new to this site but was looking through some of your comments. Not to take anything away from the person that originally posted this topic, but my situation is very similar. I just need a good honest opinion here.

I live in San Antonio so we don’t get that much rain, but we do get our share. However, this is what I have…

I just built a 17x42’ addition with a 2.25/12 pitch roof. I used #15 tar paper and overlapped it per the directions. I used 20 year Owens Corning “classic” shingles, which clearly stated that they were good for 2/12 pitch and up. So, as far as the installation instructions, the shingles are good to go.

Now, this is my delimma. I have the ENTIRE roof done, and now I read that maybe I should have used roll roofing or a #30 tar paper underneath. If I don’t have any leaks so far, do I really need to do anything? Just like everyone else, I am working on a budget, so I really do not want to tear the entire roof off and start all over again.

If you can offer anysuggestions, please let me know. Like I said, everything is flashed correctly, the shingles are done and it is currently NOT leaking. It was leaking before, but it was because my flashing wasn’t done correctly.

Thanks in advance!!!

Mike
San Antonio, TX[/quote]

If it ain’t broke, then don’t fix it.

Seriously, I’d just keep an eye on it and address it only if leaks develop.

That’s what I was seriously thinking, but all this other talk about it will definitely leak, pitch too low, double tar paper, rolled roofing materials, etc. All of that made me second guess myself. Now, will it have a greater chance of leaking from sitting water, why yes it will, however, because of the lack of rain we get here in San Antonio, I’m not really too worried about it. I had a covered deck on there before and the pitch was WAY less than that, I mean WAY less and it was shingled and never leaked. That had been on there for about 10-12 years before I tore it down to build the addition. I know that people suggest things to overbuild, which is no problem either. I would respect something more if it was overbuilt than something that was just thrown together.

Thanks again!!

Mike

again i allways fall back to " what are the neighboors doin".
if others in the hood are doin just fine then yours can too.

gweedo.

All of the model building codes have slope limitations for asphalt shingles.

On roof decks with a slope less than 4" in 12" to as low as 2" in 12", the underlayment must consists of a minimum of 2 layers of #15 asphalt-saturated felt applied shingle fashion. Asphalt shingles may not be applied on roof decks with a slope less than 2" in 12".

When the January mean temperature is 25-degrees or less, or when there is a possibility of the formation of ice dams along the eave and a back-up of water, an ice dam protection membrane must be applied. The ice dam protection membrane should start along the downslope perimeter edge and extend upslope a minimum of 24" past the inside of the exterior wall line of the building. On slopes less than 4" in 12" Most manufacturers recommend extended the ice dam a minimum of 36" past the inside of the exterior wall line of the building.

roll ice and water shield and put a 4 inch bond on the exposure instead of 5 inch and you’ll be fine

Shingle manufacturers will warranty a 2/12 installation, but I wouldn’t recommend shingling a 2/12 pitch.
I would rather go with the peel and stick guy. That would be a better roof for that area than shingling. Especially if you’re in an area with snow build-up and ice dams.

Nail Guns: Don’t be afraid of these tools, or the people that use them. It all comes down to the installer, some roofers take care in what they do, and other just want to “git er dun”. Before I start applying shingles I hit a few nails to see how my pressure and depth are, making adjustments if needed. I also remove an entire shingle if I accidentally have an exposed nail, I have met guys with the idea that if the exposed nail is laying flat, water will just run off of it. Those are the “git er dun” type I am referring to.

Mike, there is nothing you can do now that won’t cost you a pile of money and labour. As recommended, just keep an eye on it.

What do you think of the Liberty 2 part roofing system? Roofer who suggests no shingles wants to use this system: self-adhered base sheet topped with a self-adhered granulated cap sheet. He suggested doing it in white. The roof with be a sienna brownish color. I’m not sure what is thought process is on that one, as Liberty offers different colors.

Go with Certainteeds Flintastic Base/Cap.

roll ice and water shield and put a 4 inch bond on the exposure instead of 5 inch and you’ll be fine