metal over shingle roof?


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Old 01-24-05, 02:30 PM
b-bad
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metal over shingle roof?

can you put a metal roof over a shigle roof? a friend of mine said that all i have to to is put wooden slats down (like 1"x6") and just nail or screw em down, then put the metal right over it?

if it can be done like this, what about the valleys? what goes there?
 
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Old 01-24-05, 07:09 PM
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Yes.
There are several metal roofing products that will let you go directly of shingles. "Metalworks" comes to mind.
There are also "standing seam" metal roofs that can be used over shingles.
 
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Old 01-24-05, 07:41 PM
dennisjonescon.
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you can use 1x3 or 1x4......use the same on each side of the valley. The purpose is to keep the metal from rusting from the bottom up. All metal roofs will condensate on the underside. If it lays on the shingle roof it will lay in the condensation.
 
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Old 01-26-05, 10:09 PM
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Guys either install 15 or 30lb felt over the old roof if it's in extremely good shape (aka flat shiingles in great shape), but the preferred method is 1/4" fanfold installed over the existing shingles, this will cover up and hide any really bad shingle shape issues. If metal laid over felt paper with bad shingles the shingle shapes will appear through the metal and look like crap down the road.

If you wan to install nailers, the air space between the nailers should be insulated or vented. If the aire sapce is not filled with insulation or vented, you will likely have a condensation problem and this will cause mold/mildew under the metal panels and cause premature panel failure. Not using nailers will also make for a quiter roof since there is not air space for rain to turn into an echo chamber-not a problem when going over shingles, but when used in new construct you do not want air space, it needs to sit on the deck over felt paper, preferably 30lb or the new synthetic stuff.
 
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Old 01-27-05, 07:18 AM
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Another consideration is that the granules on the top of the shingles will act as sandpaper on the underside of the metal panels, causing hollidays and corrosion. Also negates any warranty on the metal panels. Use felt or batten strips under the panels. If battens, I would avoid 26 gauge panels (24 ga instead) or keep the battens close together to avoid long spans.
Jim
 
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Old 01-27-05, 04:27 PM
b-bad
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Talking

thanks a lot guys!!!! the shingles are in bad shape, well they still look good but i got all itchy from the fiberglass in the shingles when i hung christmas lights up.

even w/the felt paper down over the old shigles, it will still show through down the road? how do i eleminate that? double felt? crisscross pattern?

so i need to lay felt down in a certain pattern, fan fold?

then lay slats down horizontally every so many feet and use insullation or just felt and lay down right over it?

what are nailers? you mean nail guns?

so if i lay 30# felt down, i can lay the metal right over it?

how do i do the valleys? lay the valley down then use a nibbler to trim the tin to it w/so many inches overlay?

is there a ridge vent that i can use as well like in shingles?

how large or wide of a cap do i need?

what do i need to attach the metal down with, ive done metal buildings but they were always metal to metal w/perlin screws or lapping screws. what do i use for wood?

thanks a lot guys!!!!
 
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Old 01-27-05, 04:33 PM
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We could go on and on with these little questions and you still might not get the the exact details your looking for.

Your best bet would be go to the place your going to purchase all your metal roofing material/accessories. They will have any and all info your already asking in packet form along with catalogs with individual peices and dimensions of all things involved with installing a metal roof. It'll take all of 10 minutes to get that information and since your going to buy from them, they will help you out with any literature/advise needed to get you going.
 
 

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