Shingle roof to Metal Roof

[swifty]

Howdy. I'm going to be replacing the roof soon and have a few quick questions. Current roof is 14 yr old 3 tab shingle roof with some hail damage from storms a few months ago. I'm going to put the metal roof (rpanel) on myself since it is a simple roof and only a few cuts to make.

Should I put 30 lb felt down before I start placing my 1x4s? Seems I could just attach the 1x4s directly to the existing shingles and decking.

Should I take off the existing shingle ridge vent or just keep it in place? Seems like I could leave it in place and just put the metal ridge vent over the new metal roof and old shingle ridge vent but I'm worried about proper ventilation.

Any direction would be appreciated.

swifty

[dwilliams35]

A) I'm not a metal roof expert by any means, but having put a few on, I'd say you're going to have a really hard time getting it to stay down and keeping it straight putting it on top of a composition roof: I could be wrong, but I think I'd rip the shingles off first, deck it, put felt paper on then the roof.
B) have you looked at any of the hidden-fastener metal roof styles? The screws aren't out in the rain, so there's reduced danger of leaks. Looks a lot cleaner, too.

[swifty]

dwilliams35 - I appreciate the response. Still undecided on what to do but I hear it's common to put metal over a single layer of shingles. I'm just worried about proper ventilation in the attic. I hadn't heard of the hidden fastener metal roofs you speak of but will look into that as well. Sounds interesting.

Thanks again
swifty

[rodwade]

A commercial company came out to our lake house and installed one. Directly over shingles, no felt was used, simply nailed 1x4's down and it went on top. From what I've been told you can lay EPS foam down at that time for some added insulation. On our ridge vent they skill sawed the old ridge vent out and put thiers on.

[SaltwaterAg]

Just saw my neighbor get a new metal roof a couple weeks ago. Put the 1 x 4s right on top of the shingles and then the metal roof. Didn't see what they did with the ridge vent.

[jferrell1211]

I;ve done a lot of these, put the wood furring strips directly on the shingles---use screws---no nails!!! make sure the screws will penetrate all the way thru the decking beneath the shingles-penetrate at least 1/2-3/4 thru the decking---you can shim up the furring strips where necessary to achieve plane---don't leave the old ridge vent there---rip it up and just use the new one for the metal roof--the hot air escaping needs the least possible hinderance to evac the attic space....good luck!

[swifty]

Thanks for the responses...in particular, the ridge vent response. I'm getting started this weekend in this opressive stink'n heat.

swifty