I need a new roof.

My house is 15 years old and the 30 year asphalt roof is done. Tried the rabbit hole of warranty and abandoned that. The poor lifespan plus the fact that I have wind damage makes me consider steel. I know it will cost more but if I do it myself I can mitigate that somewhat. To make it easy I was thinking about laying it right over the old asphalt, which is apparently a common way of doing it. Not only will it save a big messy step, but I can add a few sheets of steel a day as my schedule allows without peeling the old roof off and having a hard time cap. 

Anyone done this? Any tips or advice?

I haven't done it but I did see a place close to me lay the metal over the asphalt. There was dimensional lumber (1x2?) across the roof for furring strips and the metal screwed to those.

Rons said:

I haven't done it but I did see a place close to me lay the metal over the asphalt. There was dimensional lumber (1x2?) across the roof for furring strips and the metal screwed to those.

This is what I have seen done. 

I considered it on my last house but ended up paying to have it done. My current house has one of those complicated roofs and insurance was footing the bill so it got shingles as well. 

If you have wind damage, it may pay to call your insurance company. They may pay for part of it. 

I don't think I would do it, just because of the added weight.  Metal roofing doesn't add that much weight, but why add weight to weight.  The ridge of my house is slightly bowed down at the center, probably due to multiple layers of asphalt.  I am replacing the roof this spring after taking it to bare plywood, the ridge is not something I care to correct.

I have, but full dislosure- my uncle, father, and grandfather are all in various sheet metal trades.  I spent three summers coppersmithing under ym grandfather's eye, with 90% of it being standing seam copper on state buildings or $$$$ private schools. 

It is 95% not hard, with the right tools, mechanical know-how, and patience, you can create a very nice, long lasting metal roof as a DIY.  If you have specific questions, I am happy to help in any way that I can, but I would add these few cents from the jump- 

- Roofing over asphalt is totally fine.  Use 1x3s every 2' perpendicular to the seam panels, and make sure you use long enough nails (You'd be surprised). 

- I much much MUCH prefer interlocking and "fold-over" standing seams to some of the newer pre-fab panels with separate locking V-trim over two butt-seams.  If you only want to do it once, do it right, with actual TRUE interlocking seams.  I've seen several roofs take wind and rip the V-channel clear off the house, causing leaks and other issues. 

- When you fasten your brackets, use tin snips and make a shallow cut on the seams, so one panel can't slide down the roofline from its mate.  It's just an added layer of just in case, and takes minimal time to do. 

- With any complex angles or valleys, I'd recommend water shield 3' on either side, just to be double sure. 

- Be sure your ridge cap allows proper airflow if your existing roof vents through the ridge.  I've seen some awful horror stories of black mold in attics because someone laid their metal roof up and over a ridge vent without keeping airflow open. 

golfduke said:

I have, but full dislosure- my uncle, father, and grandfather are all in various sheet metal trades.  I spent three summers coppersmithing under ym grandfather's eye, with 90% of it being standing seam copper on state buildings or $$$$ private schools. 

 

It is 95% not hard, with the right tools, mechanical know-how, and patience, you can create a very nice, long lasting metal roof as a DIY.  If you have specific questions, I am happy to help in any way that I can, but I would add these few cents from the jump- 

- Roofing over asphalt is totally fine.  Use 1x3s every 2' perpendicular to the seam panels, and make sure you use long enough nails (You'd be surprised). 

- I much much MUCH prefer interlocking and "fold-over" standing seams to some of the newer pre-fab panels with separate locking V-trim over two butt-seams.  If you only want to do it once, do it right, with actual TRUE interlocking seams.  I've seen several roofs take wind and rip the V-channel clear off the house, causing leaks and other issues. 

- When you fasten your brackets, use tin snips and make a shallow cut on the seams, so one panel can't slide down the roofline from its mate.  It's just an added layer of just in case, and takes minimal time to do. 

- With any complex angles or valleys, I'd recommend water shield 3' on either side, just to be double sure. 

- Be sure your ridge cap allows proper airflow if your existing roof vents through the ridge.  I've seen some awful horror stories of black mold in attics because someone laid their metal roof up and over a ridge vent without keeping airflow open. 

 

 

 

 

 

Good info thanks!

People always try to save money by leaving the old shingles in place, no matter what's going over it.  It's a fools' errand.  It takes the roofing crew about 2 hours to strip one whole side of the house with flatty shovels and a dumpster.  A lot of times you can get / make a roofing shovel with a notch in it for pulling nails.

If the old shingles are deteriorating, why would you want to make them into an integral part of your new roof?  Just get em off there and be done with it.  Lay fresh roofing felt over the sheathing and go to town.

With metal roofing you will still want the furring strips.

Years ago our town allowed 2 reroofs - then tear off.  Had to be crazy - it's no longer allowed.  

First roof lasts 25 years.

Second roof lasts 15 years.

Third roof lasts 8 years.   

Call Corey Flockstra from A-corn roofing. PM me for his number if you want.

His guys stripped my old shingle roof, new underlay, new vents, steel roof, new gutters, downspouts and fascia boards, all for a very reasonable price.

The jobsite was spotless the whole time as well. This was a big deal to me as i've seen what a lot of roofing crews do. He did a bunch of work for my old boss as well.

ShawnG said:

Call Corey Flockstra from A-corn roofing. PM me for his number if you want.

His guys stripped my old shingle roof, new underlay, new vents, steel roof, new gutters, downspouts and fascia boards, all for a very reasonable price.

The jobsite was spotless the whole time as well. This was a big deal to me as i've seen what a lot of roofing crews do. He did a bunch of work for my old boss as well.

Thanks Shawn. I know the guy who did the first one and if it comes to that I will hire him again. Not his fault I got a bad batch of shingles.