2:12 low slope roof + shingles
 

Can anyone point me to a Code (National or State) that allows shingles to be placed on this type of roof - and do you do them in your particular area? If so, what extra precautions would you recommend apart from Ice Shield throughout. And if you do not do them, what is your reasoning?

They (ie 2:12 and shingles) seem to be according to code in Florida, but is there a particular requirement in Florida that would be overriden in, say, the Northeast or in Michigan where snow and ice are more common.

Just looking for insight from those who are in the Northern part of the country who run into this question...in my case I have a 30yr old, non-shingled 2:12, very little ventilation and trying to get ready for the inevitable :huh:

You can read the Steep Slope Manual by the NRCA Online for free by just registering here:

http://www.nrca.net/rp/technical/manual/default.aspx

Also, check out:

http://www.asphaltroofing.org/

for the ARMA publications.

Ed

It's not recommended by any shingle manufacturer for obvious reasons that you seem to already know. That being said, there have been occasions we have done them and haven't had any problems.

Aside from the ice/water, I highly recommend installing them the hottest, driest time of the year to ensure maximum sealing. Make sure your exposure is tight and proper, and make sure your endlaps are extreme. For ventilation use shinglevent II as others tend to allow wind-driven rain and snow to pass through on occasion, especially at that low a slope.

You might also want to consider an SA system (certainteed flintlastic 3-ply is my preference) as your roof is what they were designed for.

Good luck and hope this helps.

not a chance would I shingle 2:12. especially not when I know ice will be sitting on it.

Can you repitch it? If not, use an alternate material.

Flintlastic (Certainteed), or a BUR, or a single-ply.

Thanks guys...can you not put down an Ice&Water shield all over i.e complete coverage, then shingle on top of that?

I have done this in the past here in the northeast and had no problems so far. but only if there was no other option . I have installed Ice & water Over the whole deck then installed shingle mate. And then installed the shingles with a 4" exposure. like I said I would look for other alternatives before going this route. no guaranties from me or the manufacture.

BuletBob: why would you install ShingleMate and Ice&Water shield? can't you substitue I&W for the ShingleMate, and shingle over either one? I thought ShingleMate was a premium felt. :huh:

the shingle-mate will help wick any moisture that could form under the shingles

Which proves that it is sometimes harder and more costly to do it wrong than to do it right in the first place. By the time you do all that, you could have put a proper SA system on it like should be on it in the first place.

Like OnB has said ... regardless of what your underlayment is, or how many underlayments you put down, you'll end up with thousands of holes thru all the layers of your underlayment(s) with a 2/12 pitch (and that's where the roof isn't deflected).

LIKE I STATED EARLIER IF THERE IS NO OTHER OPTION. by al means I'm Not saying its the right way. just because it worked for me here does not mean it will work else where.It all depends on the situation. especially up in Canada. I'll give you one example re roofed a house with a front porch clearly visible from the street. the existing roof was sixty years old. two layer. we strip shingles off got down to the first layer they where installed over two layers of building felt and 4" to the weather, these shingles where all doubled nailed because they lacked the wind seal tar strip. I suggested to the owner a metal standing roof would be more practical then a split sheet roof. well cost was a factor with the metal roof. they did not want the split sheet or rubber, there defense was the fact that the old roof was water tight and had never leaked. I told them that i would install the ICE & WATER over the complete deck with the shingle-mate then the shingles 4" to the weather. the owner knew of the consequences of the voided warranties from me and the roof manufacture, and agreed to take the chance. its been 8 years and it still is holding up. How I know! its my neighbors house. If it was going over a heated area NO!! I would not of taken a chance. But this is what I call a judgement call. where the owner new of the repercussions.
Anybody can call themselves a carpenter or craftsmen but a good carpenter or craftsmen will find a solution to the problem. Which in this case with four generations of experience I truly feel I achieved.