Building codes / roof angle

Jun 16, 2005 18 Replies

We are building a roofed deck off the side of our manufactured home. We are at the stage where we are beginning to frame the roof. It's ending up to be 10 feet long with a 6 inch drop. Will that meet code do you think? I live in Portland, Oregon area with very little snow. Roof will be shingled. Thanks for any insight you can give.



Alan



What does your building code say?

Ask your local building official. My short answer is that a roof like that could catch a lot of fish.

-j

On Thu, 16 Jun 2005 16:22:00 -0600, J wrote (in article ): Some municipalities post codes for porches on-line. Do a search.

I looked at one for San Diego as a reference and it specified 1/4" per foot of pitch minimum.

-Bruce

Anywhere on the internet I can find specific building code information like that? How does one go about finding that kind of information without having to ask an inspector each time?

A Google search turned this up in about 0.5 seconds...

TweedleDee, Well, from my years of doing concrete work, city sidewalks here in Eugene, had to slope 1/4 inch to the foot for drainage. You have that covered. As far as snow load, I don't know. 2x4 @ 16 on center would handle most snow loads, except maybe one like the snow of 69 (3 feet here in Eugene) Major concern would be on the support posts and how they are cross braced to prevent racking. robo hippy

Alan wrote: We are building a roofed deck off the side of our manufactured home. We are at the stage where we are beginning to frame the roof. It's ending up to be 10 feet long with a 6 inch drop. Will that meet code do you think? I live in Portland, Oregon area with very little snow. Roof will be shingled. Thanks for any insight you can give.

You might check out the instructions on a bundle of the shingles your thinking of using, as to their minimum recommended pitch. I'm betting the least pitch they'd want you to use them on would be around 2" in

12". You're at 3/4" in 15". Can you use another type of material? There are some peel & sticks available, pretty darn cheap, and work well if kept coated. Tom

That is basically a flat roof. Shingles won't work. You will need to use a membrane system, of some sort. Typically that was built up, hot mopped, roll roofing with gravel on it. These days there may be a more modern method.

As has been said, this is almost a flat roof. You can look into a product all 'Mule Hide'. This roofing material is made for flat or nearly flat roofs. It has a 20 year guarentee. I have this on the roof of my house and like it. Much better than a tar and gravel roof.

We always use a membrane system, but we use modified bitumen, a.k.a. SBS. It is sold as roll goods, (NOT roll roofing) and comes in about 5 colors from different manufacturers. If you know what you are doing, you can put this stuff down cold and not have any problems. We put it on 0 slope roofs all the time in cold adhesive as our city is frowning more and more (as are our clients) on our noisy, smokey, sulphur belching kettle.

But if you are forced to use shingles by a deed restriction or city code, then there is a way. Cover the whole roof area in self adhering/self healing ice and water shield over 15# tin capped felt. Then nail your shingles on. The shingles are cosmetically more pleasing and are UV resistant. The ice and water is uglier, and has no UV resistance (unless the half lap kind), but it will "heal" around the nail holes.

Do yourself a favor and have someone with experience do the tie in to the existing roof. I sure make a lot of money fixing those...

Robert

Is this a troll? 6" in 10 feet with a shingled roof? Regardless of the code, it does rain in Portland, and the shingles won't be happy. Just look at a bundle and see what the minimum drop is.

If you are shingling the roof, you need to have 3" of drop for each foot of run, or the water will not run from shingle to shingle.

If you have to have that small a slope, about 1/2" per foot of run, you can cover the roof with glued down rubber roofing, and you have a working roof.

Snow load isn't the problem, waterproof is.

Walt C

That's not steep enough to meet any shingle manufacturer's requirements that I know of.

Yes, it will meet code. But, you have limited options on what you can use for roofing material. This is a perfect application for either a modified bitumen, metal, fiberglass, poly corrugated. It will fall out of code if you use any shingle product whether it be wood, slate, composition, etc. SH - Building contractor from the north oregon coastal area.

You probably should have checked with your local officials to see if you needed to get a building permit before you started. I just built a deck in Coeur d'Alene Idaho without a roof and still had to get a permit.

_Shingled_ roof needs a *LOT* more slope than that.

roll roofing is indicated.

"code" requirements are anybody's guess. Copys of relevant code are available from city hall -- for a fee; or they can tell you where to procure the 'national standard' on which their ordinances are based.

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