View Full Version : Roofing Question

Gerold Griffin
09-29-2012, 9:42 AM
We live in a double wide moble home with a 3/12 pitch to the roof. Also about 30 miles from the coast wich puts us in the hurricane area. Durinng Isaac we lost enough shingles to warrent a new roof. After the new shingles are installed if I came back and put a small bead of something like Liquid Nails or roof tar under each tab to hold it down. Would it make any differance? I am thinking if the wind can't get under them they won't go anywhere. I considered going to a metal roof but the wife isn't to thrilled with the idea, it also cost more which is a major issue right now. I have also seen where they have a dimensional shingle without tabs that is thicher which is supposed to hold up better in windy area's but is it designed for 100+mph wind lasting 8, 10, 12 hours? Short of moving what are your thoughts?

Todd Burch
09-29-2012, 10:00 AM
I had my roof replaced in March this year due to hail damage. I live in a Hurricane area too. When my roofer was here, I asked him why his guys weren't removing the little clear Saran-wrap looking plastic film under each shingle as they were installing them. I thought they were merely a separator so that the shingles would not melt together while still in the paper package. He explained that the thin piece of film was actually glue material that would melt once the shingles were installed, and it did what you are suggesting.


Gerold Griffin
09-29-2012, 10:17 AM
Todd on the shingles I have seen that film is about where you nail it down at. What I am thinking is applying a adhesive/mastic about 1 inch up from the bottom edge of each tab to hold it down.

Jason Roehl
09-29-2012, 10:45 AM
Todd, you are right about the plastic film--it is merely to keep the shingles from sticking together. No need to remove it, and if it melted, all those companies that store their shingles outside year-round would have a mess on their hands. You'll notice that the plastic strip is on the back of the shingle--when stacked in the bundle at the factory, it lands on the tar strip of the shingle below it.

Gerold, that factory tar strip is exactly what you are proposing to do--when shingles are properly laid, that tar strip that runs across the middle of the shingle ends up below the bottom edge of the tabs of the shingle in the next course up. A warm, sunny day is all that is needed for the shingles to bed together.

Dimensional shingles, IMO, are the only way to go. They are thicker, more wind-resistant and better looking. They're also easier to lay--there is a pattern to aligning them vertically, but minor variations don't show like they do with a 3-tab shingle. Even slight meanderings in the horizontal lines don't show as readily as with a 3-tab.

Nailing is also the key to wind resistance. The nails need to go where the manufacturer recommends, and the reveal of the shingles needs to be correct. There are several reasons for this. One is that each nail needs to go through two shingles--usually this means nailing between the tar strip and the top of the tabs (on 3-tab), or the top of the dimension on dimensional/architectural shingles. Also, the horizontal spacing of the nails is important so that a nail in one shingle does not end up within 1" or so of the ends of two shingles in the next course up. If it does, the head of the nail should be covered with butyl rubber caulk. Many people mistakenly believe that the shingles should be nailed in or above the tar strip, thinking that this would put the nails inside the sealed envelope of the shingles. The problem is that this puts the nail too high where it may not catch the top of the shingle underneath, and it makes the tabbed area deeper, which gives the wind more leverage if the tar strip has failed or has not yet set.

I've done a couple of my own roofs (two different houses), helped a few friends do theirs, read many of the installation instructions on shingle bundles and have read many articles on the subject from magazines such as Journal of Light Construction and Fine Homebuilding, plus I'm around construction as a painting contractor (I have a tendency to pick the brains of other tradesmen on how to make my own projects better and easier).

Tim Morton
09-29-2012, 11:59 AM
how about doing a metal roof?

Lee Schierer
09-29-2012, 5:35 PM
Your roof pitch is right at the minimum recommended for a shingle roof. If possible change the pitch of your roof, which will also change the ability of the wind to get under the shingles. Regular 3 tab shingles are probably not heavy enough for that shallow pitch. You probably want to use architectural style shingles which due to their multiple layers are stiffer and are likely to be more wind resistant. You also want to look for the longer life warranty as they will also be thicker construction. Be sure to check the wind rating and minimum pitch requirements before purchasing and installing them. Be sure to use roofing nails that are long enough. Don't use staples as they pull through too easily. Pneumatic roofing nails also give slightly less hold down than convention roofing nails. Consider beefing up your roof sheathing to be 5/8 or thicker and don't use wafer board, use ply wood as it lasts longer, particularly when it gets wet. You may also want to install ice and water shield on the entire roof to give you a glued down layer that would be impermeable should the shingles be taken off.

Adding tar or construction adhesive will likely void the warranty on the shingles.

Bill Rogers
09-29-2012, 6:00 PM
If you add roof cement (don't use Liquid nails) 1" from the bottom of the shingles, it might seep out onto the shingle below it, creating an ugly mess. A 3/12 pitch is almost the minimum allowable pitch for shingles, however, the lower the pitch the better the shingles end up sealing (DAMHIK).

Richard Jones
09-29-2012, 10:31 PM
Most shingle mfgrs. call anything less than a 4/12 a "low slope" and require continuous ice shield or other approved underlayment. They also usually mandate a smaller reveal than the typical 5".

phil harold
09-30-2012, 12:27 AM
Use a 6 nail nailing pattern for high wind applications!
A heavy shingle architectural or dimensional shingles will help too
there used to be interlock shingles but I have not installed any of those for 20 plus years...

Gerold Griffin
09-30-2012, 11:25 AM
Sorry I didn't make it back yesterday everyone but another of life's little things had to be dealt with and when I got back in I was all kinds of done! (Feel asleep in the recliner)
Jason you have a valid point on the nailing pattern. It defininatly needs to be done right. Also as you mentioned the tar strip goes across the middle. On the tab end there in nothing except hope that the sun will "bed" them togather. As was mentioned that plastic film should be removed and is only there to prevent them from sticking togather while in storage. Since there is no film across the bottom of the tab that says alot. My thinking is that by putting say roof tar or other adhesive under the tab to secure it the wind would have a harder time getting under it. Once the wind gets under any roofing material its all over.
As a note a roofer came by with his quote that I know quite well. I asked him what he thought. He seems to think that I am definatly thinking outside the box. I take that as a good thing. As for doing any good or not he is unsure. He did bring up some points mentioned here and some others. What I may end up doing is a small test area and see what happens during the course of a year.
Lee changing the pitch of the roof is definatly not an option. Changing addresses will happen first!!!
Bill yes roof tar may very well run which is why I plan to look at some other material for my test area. If it runs or anything there only a low flying pilot will notice. Nuts to him!!
Phil, I remember those interlocking shingles of years gone by!!! Those things were great in many ways but you just don't see them anymore. Shame to since I always felt that they even looked better, course that's just my opinion.

Myk Rian
09-30-2012, 11:53 AM
how about doing a metal roof?

Read the OP for that.

I considered going to a metal roof but the wife isn't to thrilled with the idea, it also cost more which is a major issue right now.