Leaking roof

freebird62 · Sun Aug 14, 2011 5:47 pm

Ok, here is my question. I have an extension on my mobile home which is 34ftx13ft. It is currently shingled. I have had two contractors out to get the roof fixed to stop the leaks. The quote from one will put on shingles again and the other wants to put a rubber roof on it due to the NO pitch in the roof. Yes it is pretty much flat with a small incline. Am I getting taken for a ride?? Should a flat roof have something other than shingles?? And if so, why didn't the other contractor notice this? I am a single female, trying to keep my costs down. The shingles are in good shape. The area of leakage is coming from where the mobile home connects with the new addition. Any guidance will surely be appreciated. Thank you.

Greg · Sun Aug 14, 2011 7:59 pm

Shingle roofs DO need a pitch to work properly. I am not sure of what the minimum pitch is, but I am sure JD will see this and have better answers for you.

Greg

JD · Sun Aug 14, 2011 10:09 pm

Shingles are the wrong choice for a near flat roof. Shingles need a minimum 2.5 in 12 slope, which means that if you drew a level line from the lowest point of your 13' roof, the distance from that line to the highest point of the roof would be at least 32.5". Only the steepest of mobile home roofs will have a slope like that. If you say almost flat, then it is not even close. The 2.5 in 12 requirement is written on every bundle of shingles that I have ever seen. Less than 2.5/12 voids the warranty, which is pretty worthless anyways. The warranty would only come into effect if there was an actual manufacturing defect, which is pretty rare.

A rubber roof is an excellent choice for a low slope roof. You want the contractor to be sure that the roof is properly supported and will not pond water. Making sure that the existing roof deck has no dips and to be sure the rigid insulation foam panels are properly installed should do this.

Rubber roofs are not the only choice for a low slope roof. A "torchdown" modified bitumen roof is usually much cheaper, but will have a much shorter lifespan. Some mobile home roofs are not good candidates for a torchdown. There are also standing seam, metal panel roofs that will work well with low slope. Their prices will be in line with the rubber roofs. Which is better? Depends on design, installation and the contractor installing the product. Another option is a "Liquid Rubber" roof, which is epdm rubber in a bucket which is spread over the roof. You could also do a multi-layer elastomeric roof with embedded roof fabric. When I install this type of roof there are a minimum of 6 layers.

The shingle bid was probably considerably less than the rubber roof bid. But again, that product should never be offered for a low slope roof, and I would not trust any contractor that would offer it. They certainly don't have your best interest at heart.

I hope this helps

freebird62 · Mon Aug 15, 2011 10:26 am

Thank you Greg and JD............I am so thankful you guys are here for folks like me! I was so confused as to who was actually taking me for a ride or not and your explaination was wonderful! I feel like a knowledgeable consumer now, thanks to you! Last nights rain took a toll on my ceiling. Once the roof is completely leak proof, the drywall will need to be replaced. Thanks again for all that you do!
Janet

freebird62 · Mon Aug 15, 2011 2:02 pm

JD, another question, please.......if the flashing between the house and addition seems to be the problem, and the shingles are good would you still remove the shingles or just fix the area of the flashing? I hate to spend a ton on something that might be an easier fix. I have applied tar over the time to the seam between the two roof's and just last year a friend of mine laid down a product like contact paper over the same area.

I ask this now because someone mentioned that a rubber roof does not do well in extreme temperature changes. I live in NE Ohio. Does this really matter???

The quote on a 13' x 34' roof with Torchdown rubber roof is 1768.00 What do you think about that cost??

The quote for the shingled roof was 1485.00.

Thanks again for your input!!! I trust you and am finding that those I have spoken to or gotten quotes from .....I am unsure about!

Greg · Mon Aug 15, 2011 5:14 pm

Another thought, have you considered a steel roof? They should work on a low pitch roof with no problems.

Greg

JD · Tue Aug 16, 2011 12:45 am

If the flashing is the problem, it is probable that it is a design issue. I like at least a 2" drop from the bottom of the roof edge metal to the second roof being flashed. Other wise on a flashing joint that is almost flat, the metal flashing will "oil can" and warp causing chronic leaks.

Shingles on a flat roof will work for a while if there is Ice & Water Shield or conquerable product under it. But before too long, shingles will curl up and water starts going sideways. Now it is only the Ice & Water Shield keeping you from leaking.

The flashing probably can be repaired/replaced enough to keep from leaking for a while, but I would want to replace those shingles with a different roof.