Metal Roof Question

[peter nap]

I've never put one on and don't know anything about them. Can anyone point out the pros and cons about the different types and point me somewhere that can give me some information about installing them.

I see all kinds. Folded seam, standing seam, some kind of panel that has a U shaped groove on the side. I don't know what kind of fasteners or how to fasten them.

Thanks in advance!

[rdpecken]

Hi Peter.  We just put a metal roof on our little house this month.
We went with a standing-seam, hidden fasterner system from http://www.metalroofingsource.com/, also known as absolutesteel, in Tempe AZ.

We chose this system for three reasons:
1. There was no shipping charge, as we picked up the roof at their warehouse in Tempe, which is only a few miles from our home in Mesa. Shipping charges to other locations would be about $85.00
2. This was the only site on the internet that I found that actually encourages people to do a DIY installation.
3. The hidden fasteners not only make a cleaner installation, they are less likely to leak in the future.

Installation was fairly easy, with the panels only taking about 10 minutes for each one.  The real time-eater was the gable ends trim, and the final panel on each side of the gable roof.  We never figured out how to make the joint at the top of the gable look good up close.  We have some extra pieces, and may do some experimenting at joining them at a 45-degree angle, then re-do that part. (We have a 12-12 pitch).

Fasteners: The panels were held down on one edge by #8 x 1" phillips pan-head screws.  These are installed under the seam of the next panel, and so are naturally waterproof.
The trim was held on by #12 x 1" hex-head painted screws with rubber-like washers.
At the bottom of each panel, near the eaves, we installed 2 #9 x 1" painted screws with washers, because we are in a high wind area.

We started with a standard plywood sheathed roof...


Then we added underlayment ($162, and worth every cent) which only weighed 30 lbs for the whole roof!



After cutting out the ridge-cap vent and installing the vent screen, we started on the metal parts.
After installing the eave-trim along the long edge, we put on the first panel, and the first gable-trim.



The we put all the rest of the panels on that side, with each panel snapping over the previous one's seam, and fastened on the other edge with screws. Then we finished off the other gable end.
Repeated for the second side, and attached the vented ridge cap.
A little more planning or practicing would have prevented what few mistakes we made (gable trim).

We bought an electric shear from harbor freight for $39, but could have done all of the cuts with simple hand shears.
The panels were cut to the length we specified at the factory.
The only cuts we had to make were:
Trim pieces (they come in 10-foot lengths).
One panel on each side of the gable (the roof was not an even multiple of 16").
Ridge Cap to length (again, they come in 10' lengths).

Even with the 12-12 pitch, and the difficulty at the top of the gable, we would still choose this roofing over asphalt shingles.  It was just so much easier, and it makes a Great looking roof (even for amateurs...)

Finished roof:





You can see our whole saga at http://www.arizonaranch.org
Good luck... Randy P.

[peter nap]

Thanks Randy!

I'll spend some time looking at the system. It looks good and since I can order the panels to length it should go up much easier. I don't envy you on the 12/12 roof. I've shingled a lot of buildings and as a matter of fact, am re roofing my house now. It's 6/12. I did one 12/12 and it scared me silly.

I looked over your site and it looks like you did a wonderful job. Good plan to do the big house later. I'd do the same but I doubt seriously I'll live another 10 years....so if I want to sit on the porch looking at the river, I'd better do it now.

[glenn kangiser]

Do you have a brand name or web site for the underlayment, Randy?  Thanks.

[Ernest T. Bass]

We've found that it really helps to mark out each panel's position on the roof prior to laying the metal, if it is important for the last panel to line up straight.. Especially if your roof isn't perfectly square, measuring it out ahead of time and than scooting each panel to it's line as you go will line you right up when you get to the other end.

Maybe that's a no-brainer, but we started putting metal down with no idea of how much the sheets can run off if you're not careful...

[glenn kangiser]

Good point Andrew.  You are correct - each sheet can stretch or shrink a half inch or more.  Times a few sheets gets to be big numbers.

[rdpecken]

Glen, The underlayment is Berger Pro-Master Roof Shield.
We mostly picked it because it is spec'd to last 1 full year exposed to the elements.  we put it up in June, just before our monsoon season started, and when we came back in August, there were no tears or rips of any kind. Pretty tough stuff... The roofing link in the post above has installation info and specs for it.

As Andrew says, it's a good idea to establish your vertical lines square with the eave before you put the first panel up.
We did this by pulling a string from gable end to gable end along the eave. Then we pulled a string up to the ridge along the starting gable end.

We measured 4' out along the eave string and made a mark on the string, then measured 3' up along the gable string and made a mark on the string there. Then we moved the ridge end of the gable string back and forth until there was 5' diagonally between the marks.  I think they call that the 3-4-5 method of finding square.

Fortunately for us, we were very careful in building the roof square, and were able to line up the first panel with the edge of the roof.
Since every other panel on the same side locks into the preceding one, you really want to make sure the first one is square.

[John Raabe]

Good information and a very helpful tutorial.

Almost makes me want to get up on the roof.

[Ernest T. Bass]

I've found thats it's actually pretty easy to install metal on an un-square roof, if it's within reason... It helps if the edges of the roof are at least parallel to each other, but if you plot out the panel placement ahead of time you can still make it work without being noticeable. Like Glenn said, there's quite a bit of play in each sheet. If you just scootch one end of each panel 1/8'', you'll end up with a several inches of play by the time you get to the other end. Naturally, the bigger the roof the more forgiving it'll be (though, usually more out-of-square..).