# metal roofing



## caseyj (Apr 8, 2001)

I am thinking about installing a metal roof over my existing roof thus eliminating the tear down. What is done to protect the exposed edges after cutting the valley angles and is the valley sealed to prevent water back-up?
Any info is appreciated. Thank you.


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## Manthus (Jul 5, 2010)

caseyj said:


> I am thinking about installing a metal roof over my existing roof thus eliminating the tear down. What is done to protect the exposed edges after cutting the valley angles and is the valley sealed to prevent water back-up?
> Any info is appreciated. Thank you.


Prior to buying my metal roof, I was under the impression they would go over the existing. That was not the case, they did a complete tearoff.

My valleys are entirely metal, I believe they are unsealed. It has been up for 2 years with no problems.

In terms of exposed edges, the roof has a small overhang from all edges of the fascia and has a metal trim piece that keeps the 'edge' from dripping back up into the wood underneath.


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## Take Five (May 10, 2003)

I am installing over old roofing. Removed bad shingles only, layer of felt to keep the underside of the metal from getting scuffed by old shingles. 

Valley= 1 layer of ice material, felt and then metal valley. Valley seams, I sealed with a two sided sticky !/2 inch foam meant for just that. Was expensive but it did the job. Had always experienced bad ice damming and leaks. Not so this winter!!

Wayne


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## ESOX (Nov 20, 2000)

You should tear off the old shingles. Use a Hitherm ice and water sheld at the eaves and in the valleys. Synthetic felt on the rest of the roof. You could repaint the raw edges, but I would just embed the valley ends in a matching quality caulk bead. Barring doing the old fashioned hand seamed doublelock use a system with hidden fasteners and standing seams such as this:
http://www.unioncorrugating.com/AdvantageLok.html


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## tinmarine (Nov 19, 2007)

ESOX said:


> You should tear off the old shingles. Use a Hitherm ice and water sheld at the eaves and in the valleys. Synthetic felt on the rest of the roof. You could repaint the raw edges, but I would just embed the valley ends in a matching quality caulk bead. Barring doing the old fashioned hand seamed doublelock use a system with hidden fasteners and standing seams such as this:
> http://www.unioncorrugating.com/AdvantageLok.html




If possible, tear it off. If that surface insn't flat, really flat, depending on the type of panels you choose you can get alot of oil canning. That's where you see alot of waves in the metal panning. That's from the fasteners pulling down on the panel too much. Back when I did that type of work we never sealed the valleys other than running ice and water (use Grace) up the valleys (most of the time the whole roof) and running polyurethane down the length of them as well as down the sides of each panel prior to setting the next panel. Easy little system, just trim it and start running panels. Once the trim is done the rest goes very quick.

If you don't tear off and have rotted wood, it will cause you headaches down the road.


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## storman (Mar 12, 2008)

Tear the roof off!!! Install a valley cleat to lock your panels to all you have to do is set the cleat on top of the valley in a bead of sealant and fasten it down next hem the panels down and clip it to the cleat no raw edge.

_OutdoorHub Mobile, the information engine of the outdoors_


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## -Axiom- (Jul 24, 2010)

Have you looked at the metalworks metal shingles?

http://www.tamko.com/OurKeyBrands/M...olType/categoryDisplay/itemid/20/Default.aspx

It is a hidden fastener system and the trim pieces will cover all the cut edges.

It's always best to tear off the old roof, always.


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## Cullz (Jan 4, 2011)

Always do a tear-off, personally i wouldnt use metal. Im in the buisness, and id say no. Its up to you, but in my case id go with a life time shingle, titanium underlayment and, certianteed ice and water shield six feet up off the eve and four feet in the valleys. With a good company you wouldnt have ANYTHING left on the ground, and EVERYTHING should be protected. Alyways go LANDMARK AR shingles, you pay for what you get.(Never go ashpalt shingles) always go fiberglass. Lots of crappy shingles out there, if its too good to be true, then most always is. We have tore off more "new" metal roofs than you think....P.S. you can match any drip-edge to any color your house is.


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