Hi,

I'm going to put a metal roof ( 36" wide rib type metal ) on my house which has one layer of shingles on it.

My question is can I screw the metal directly on to the shingles or is it best to put 1" x 4's or 6's wood furring strips on top of the shingles and screw the metal on to the 1 by furring strips?

I've heard from some people that condensation will form underneath the metal roofing and cause the furring strips to rot. My attic is well ventilated and insulated with vents on each gable end along with a thermostat controled attic fan.

What's the best way to put metal roofing on so that it won't cause problems later on?

Any advice is appreciated. Thanks!

David

P.S. I done a search for this type of question on this forum as it looks like it's good place to find advice when you need it and couldn't find a good answer. Sorry if this has been discussed before.

 

You need an air space between the roof and the metal on any heated structure. Also make sure you buy the longer screws so you are going through the ferring strip into the plywood or wood. Do NOT overtighten the screws, the rubber washers should remain round and not become oval. Only install screws when your strips are so you dont contort the sheets. Another thing to watch, make 100% sure your first sheet is square to your roof or each sheet will magnify the problem. If you are cutting any of the product, remember to paint the cut edge and put it on top so its covered by the ridge cap. Install the weather stripping on the top and bottom to keep critters and bugs out. Also make sure the ridge cap is securely fastened at each end to keep critters out, namely flying squirrels.

 

Ok, thanks for the advice.

What would you recommend using as furring strips?.... 1" x 2", 1" x 4", or...? And would it be wise to use treated wood for the furring strips or perhaps place fan folded Styrofoam insulation in between the metal and the shingles using untreated wood? I'm just concerned about the furring strips rotting although you said there should be an air space in between the metal and shingles. I just want to make sure I do it right the first time.

Also, wouldn't there be an opening at the eve of the house when using the furring strips and if so should it be covered with some metal flashing to keep air out? I don't have any gutters at the moment or plan on putting any up any time soon.

One other question... how far apart the furring strips should be placed on the shingles and do you simply tack them down with nails to hold them in place before putting the metal on and then use the longer screws through the metal to secure all of it down on the roof?

Thanks again!

David

 

Id use 1x 4 for the strips12" on center. Just better to walk on. P/T only if you want to. For the edge Id bend it down 90o to cover the opening there on the gable ends.I wouldnt put any insulation in there under the metal roof.


ED

 

i put a metal roof on about 4 years ago, i remove all shingles and put down 90 lbs. felt paper then metal roof with no strips, one problem with strips is during hail ,or limbs falling from trees (or someone stepping on unsupported spot) you can get damage between spacing of strips be sure and use cup shape washer screws in flat of metal NOT on ridges a

helpful site below http://www.mtlsales.com/home/

 

Interesting, i have never seen anyone install the screws on the flat except as a last resort.

 

metal sales web site , is where i downloaded infro on screws, a lot of older roofs had nails and screws on high ridge of metal, but now they recommend rubber washered screws in flat near edge of ridge, try to tell older person like my father in law screws go in flat instead on ridge, had to go online to manufactor to show pics of screws

 

I am going to install metal over shingles. What kind and length of screws would you use on the fur strips?

Black paper on top of shingles?

Would 1X3 work?

I don't have a way to get the old shingls off and hauled away.

I'd say it will outlast me

 

Welcome to the forums! Moderators may move this post since it is hijacking a 7 year old thread. Use 2 1/2" bugle head decking screws with torx head to fasten your 1x4's to the decking. Remember you have to go through 3/4" of wood, probably 1/2" of shingles (lapped) and then well into the plywood decking. Use 1x4's. Read the other posts in this thread for more information.

 

How am I hijacking a thread when I am asking a relevant question?

I am putting a metal roof on and don't know how to do some things.

For example do I have to fur if I clear off the shingles or just felt paper and screw the metal down?Also do they make an edge trim other than drip edge?

Also I have a range vent that doesnt come far above roof line. How do I "boot" that in? Some other things are the short pipes on bathroom exhast fans.

I have never done a metal roof with things cut in. I am sure they will fall in just the wrong places. I am winging it to say the least but cant afford a contractor.
Any help would be appreciated!!

 

I guess your question is not going to be moved to a new thread.

The link below has a good set of instructions for installing metal roofing. Look at the first link:

How to Install Metal Roofing | Best Buy Metals

Hope this helps. Good luck with your project.