Roof

Repair help for the do-it-yourselfer.
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Moderators: Greg, Mark, mhrAJ333, JD

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Furball

Thu Sep 18, 2008 3:42 pm

Hello Lads and Ladies! Haven't been here for a while cuz I found the handyman I had lost for many years.
It's looks like I will be buying this MH but it will need a new roof. I've been looking at the metal roof instructions in the Bible according to Mark. This is a 1993 Fleetwood Broadmore 14 x 66. It appears to have 2 x 6 framing, so I'm not worried about the weight. I do have a peaked roof and am wondering if the old (hard and wrinkled on the sunny side) shingles will have to be removed to put on the roof? Also, I have good insulation. Will I need to put in the folded insulation?


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Greg
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Thu Sep 18, 2008 5:29 pm

Furb, good to have you back. Personally I would want to get as much weight off of the roof as I could, so I would take the old shingles off. I'm sure JD will add his thoughts as well. You may want to think about rarimiter blocking as well. Greg
"If I can't fix it, I can screw it up so bad no one else can either."

Furball

Thu Sep 18, 2008 7:25 pm

Hi, Greg. What is it I should be thinking about perimeter blocking?

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Greg
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Thu Sep 18, 2008 8:15 pm

I am not sure about the weight difference, if any. I am always concerend about the extra weight damaging the home. I saw one home that had about a 4" drop in the floors along the outside walls caused by someone adding a full shingled roof and a HUGE wall window. The added weight is transfered to the floor joists and since the joists are supported by the frame rails, that allows the joists to bow downward from the weight. Parimiter blocks help support the weight directly under the walls.
I am not saying that it is 100% required, but is worth thinking about. Greg
"If I can't fix it, I can screw it up so bad no one else can either."

Furball

Thu Sep 18, 2008 8:35 pm

Does that mean I might need extra blocks along the perimeter? If so, how close do they need to be to each other?


Furball

Thu Sep 18, 2008 8:37 pm

P.S. I don't have an answer to my original questions.

altasnowman
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Fri Sep 19, 2008 12:36 am

Hello Furball, Yes the old shingles will have to come off before the new shingles can be put on. Also when they remove the old shingles it is a good time to check the roof for water damage and repair any damaged areas, and when they install new shingles it is a good idea to have ice shield put down as well. It may be a costly thing but it does pay off in the long run.What type of shingles are you going to be putting on?
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Jim from Canada
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Fri Sep 19, 2008 10:48 am

Hey Furball!
Welcome back, I just put a new roof on, I have 2x6 walls too, check out my photos, may be something there to give you ideas.

Jim
Remember, minimum code requirement is just that....MINIMUM

Furball

Fri Sep 19, 2008 11:03 am

I don't know what type of shingles. My handyman would have to figure out that one. Loved the pix. Since I don't want to have to go through perimeter blocking, I think I will stick with shingles. Are ice shields the metal pieces that go around the edge of the roof to prevent ice backing up under the shingles? If so, I would do that.

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JD
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Fri Sep 19, 2008 10:29 pm

Hi Furball,

A metal roof weighs less than a shingle roof, less than half the weight. But I would still remove the old shingles for a new metal roof and especially for a shingle re-roof.

The way it works is, a home built for our area would be built for a 20lb roof (snow) load. It may have tested out at 22.5lb (just picking a number) per sq ft when the plans were approved. So if you put on a metal roof that weighs 1.5lb psf, you would still be compliant with the 20lb roof load. Technically, that would only be true if your home can still test out at 22.5lb psf. But if you added a second shingle roof and let's say it weighs 3.5lb psf, then the added weight would lower your roof load below acceptable levels.

I have seen homes that appeared to do well with a second layer of roofing shingles, but I have also seen the weight bow ceiling and bend floors.

What is more of a concern to me about a second layer of shingles is when they install a second layer, they roll out the roof felt and install the shingles. Now the nail (pneumatic) are going through the old layer as well. Some nail will go through more layers than others, making it nearly impossible to get a good setting on the nail gun. This causes some nails to penetrate to deeply into the shingle, shortening it's life span. Also, I have read that the old layer of shingles absorb more heat which will also shorten the shingles life. Only roofing nails should be used, not staples.

The "L" metal on the edges is "Drip edge" metal. The Ice & Water shield is a premium roof underlayment, usually used in place of roofing felt or used as added protection at the roof edges, ridge cap and vents. They will also use it on valleys of a dormer. This is a thin black peel-n-stick membrane that self-heals nails and staples after the roofing material heats up from the sun.

Hope all that stuff helps.

JD
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All information and advice given is for entertainment and informational purposes only. The person doing the work is solely responsible to insure that their work complies with their local building code and OSHA safety regulations.

Furball

Fri Sep 19, 2008 10:43 pm

Thanks, JD. That was extremely informative. I believe my roof has a 40-lb rating. I would have the old shingles removed. My thought was that, with a metal roof, the snow will slide off pretty easily.
So, would I want an ice & water shield if I do a 3-4 inch overhang?
I don't feel I need more insulation (I am one of very few here, I suspect), so wouldn't want to use the fold-up type Mark shows in his book.

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JD
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Fri Sep 19, 2008 11:33 pm

Personally, I think the fanfold or better yet, 3/4" insulation board is very important. Even if your roof is well insulated, that metal panel will still absorb some heat from the roof deck. This could cause condensation.

The Ice & Water Shield (Gracie) or Owen's Corning WeatherLock, (there are also other brands) type underlayment is far superior to roofing felt. But roofing felt is also a water-proof membrane that is much cheaper. It just does not seal around all the nail punctures. Roofing felt is still the number one roofing underlayment used throughout the US by a long shot.

It is a tough decision because there is a lot of difference in your cost depending on the insulation and vapor barrier you choose. But, it is a real bummer to go the cheaper route with everything and end up with a problem roof, because going cheaper is still not cheap. I would recommend that you use the best materials you can afford, The roof is supposed to last you many years without headaches.

I would go with 3/4" polyiso foam board. It fills the voids between the 1x4 nailing strips and offers the roof panels support from snow or being walked on.

Whether you use fanfold or foam board, be sure to tape all of the seams with the manufacturers taping product. (yeah, another expense)

JMO
JD
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Today is PERFECT!

All information and advice given is for entertainment and informational purposes only. The person doing the work is solely responsible to insure that their work complies with their local building code and OSHA safety regulations.

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Jim from Canada
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Sun Sep 21, 2008 7:45 am

Hi Furb.
I would go nothing less than ice/water shield over the whole roof if you are using shingles. I would also not use anything other than Grace brand, it costs more, but you can put a nail in it, remove the nail, and the hole will seal. It will add $200 - $300 to the roof price, but that is cheap insurance when you compare the cost of repairs due to a leak in the roof. With the Grace, the roof will be waterproof before the shingles. I have no experience with metal roofing, so I will have to defer to the rest of our esteemed members on that front for advice.

Jim
Remember, minimum code requirement is just that....MINIMUM

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