# replace built up with metal



## dwightlightnin (Jul 30, 2009)

ive got a customer with a built up hot tar roof with gravel and they want me to replace it with comp or metal.do i need to remove the existing roof and replace the sheeting to install comp shingles or metal which i prefer.or is it possible to re-roof over the existing.the pitch is only a 2/12 or 3/12.oh and i live in anchorage alaska but we normally never have more than 2 or 3 feet of snow at any given time.any info would greatly help.


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## pgriz (Aug 31, 2009)

Depending on the model, you can install snap-lock hidden-fastener systems down to 1:12. Whenever possible, we always strip down to the deck, deal with any insulation/ventilation issues, then recover with appropriate underlayment, strapping, and finally the metal panels. If removing the old tar from the deck is not cost-effective, then redecking would seem to be the simplest solution. I have seen others redeck over existing T&G, but I consider that to be a cheap but not effective solution. FWIW.


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## dwightlightnin (Jul 30, 2009)

*thanks griz*

I only do skyline and delta on new construction so had no clue on how to strip the existing hot mopped roof.Ive seen alot of re-roof jobs and wouldnt want to even if i could.The customers paid some guys to go up on their roof with axes and sledge hammers to break the ice dams!And you get what you pay for i suppose because they got holes right through the decking!


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## deathray (Mar 5, 2010)

I personally wouldnt do skyline panels or through fastened under 3/12.Rather use mechanical sem.Should tear off, resheat if needed, use ice shield and vent it well.Good luck-Ray


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