The more I learn about metal roofing the less I think I want it

Hmm, If you drilled the holes and drove in the screws, in a line along the hills and not the valleys; then [assuming the height of the hill was about 1 1/2 inch] the screws would need to be 1 1/2 inch longer just to reach the rafter.

Back in the day, when screws did not come with a rubber gasket already installed on each screw maybe such was a good idea. But today when each screw is already with it's gasket, I dont see the need.

Also my snow-load was engineered at 85 pounds per square foot of dead load, and the wind sheer was done for gale winds up to 90 miles per hour. I would have to think that with each screw driven down into the steel rafters flush it would hold the sheet metal much stronger. Than if it were yet sticking out of the rafter by 1 1/2 inch.

You need some pitch just to get the water to flowing, but I only have a 1 to 10 pitch [which is fairly shallow], the 24 gauge sheet metal is very strong and can hold the snow load as well as the wind sheer.

The one obvious problem with my exposed porch roof is sweating and frosting. Metal conducts temp and differences of temp on either side cause condensation and sweating.
I definetly question the rubber washers on the screws. As I said after 2 years I have leaks. Place a rubber washer on a sheet of steel and leave it outside in direct sun for a couple of years and see how pliable the rubber is.

After reading posts on www.metalroofing.com I still think I'll stick with tried and true shingles. Almost all of the replies on here have different installation methods and it seems no one can agree on what actually works for the long term.

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"Education is the ability to listen to almost anything without losing your temper or your self confidence"
Robert Frost

My house has a metal roof installed with screws that have both a rubber washer and a metal "helmet" or "jacket" that collapses around the washer. I did develop some minor leaks on a part of the south facing porch roof where it gets a lot of sun. The roofing I chose was a dark green, which looks great, but it certainly adds heat. Under the roof, I added a "radiant barrier" that reflects the heat back out. It keeps the inside of the house much cooler, but it forces the roof to absorb double the heat, once on the way down and again as it is reflected back out. I believe this heat "cooked" the rubber washers and caused some to fail. I replaced all the screws on that section and added a good, clear caulk in each hole. So far, that appears to be doing the trick.

Even with the minor problems I've had, I would install nothing but a metal roof. I would use a silver, mill, or some other lighter shade/color instead of a dark green. I would add a good silicon caulk in each hole. Take care not to tighten the screws too much. If you install it yourself, you'll save a lot of grief by making sure that the roof is square before installation. Lengthen or shorten the lathing to get it square if necessary. If you hire someone to do the installation, consider a standing seam roof. There would be no problem with screws failing in that type installation.

Finally, metal roofs are not quiet, as has been pointed out. Personally, I love the sound of the rain on the roof, but that's not for everyone.

Good luck.

If leaking at the screws concerns you, take a look at 'standing seam' metal roofing. Different manufactures might call it different things but what it means is that none of the screws are exposed. The seams overlap and lock together. Properly installed, you won't get any leakage with this product.

For long life of the roof material consider the galvalume finish. It is not as pretty as painted, but it lasts! I would never use electro galvanized finish.

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Agmantoo
If they can do it,
you know you can!

Personally, I would swear by a metal roof. My mother's house was built in 1952 with a metal roof. All Dad ever did was paint it once in a while. It never leaked and is in perfect condition today. The attic was well insulated, so I never really heard the rain being loud. Now this house was built by the previous owner with his own hands. He was a farmer and that is probably why it was done right.

We've 2 types of metal roofing - the garage on the ribbed type which we installed ourselves, and the house - roofed in 2000 with Metalworks and professionally installed and re-roofed again in 2003 with Finall (also known as Interlock) Don't touch either of these 2 brands or their installation - we got scr@wed on both roofing jobs and it still leaks (don't believe the cr*p about lifetime warranty - you'll never see it). It can be painted or repainted or the colour changed if so desired.

The roof we installed ourselves on the garage - a big garage 30 x 70 - is standing up just fine with the galvanized roofing - the instructions we got from a contractor on it worked out just great. When the Finall roof has to be replaced, we will use either the 5-rib or standing seam on it.

You want metal roofs? Have a look at my home town -Mount Isa

Not a shingle roof in sight, place suffers from acid rain (oh, notice those large stacks there?) Temps hit 110F in summer. Can't say I've ever heard it creak as it expands, although I suppose it must on occasion. My mind probably edits it out. The metal roof in my house is the original one and is 54 years old. It had one leak when I checked last year because some bonehead installer put a sat dish up and - yup - put the screws in the valleys.

Yes, you need longer screws when you put them in on the peaks. Don't let it worry you much. Don't over-tighten them either. They only have to just contact - too tight and you'll distort that little bit of rubber and they will leak in time. Most pro roofers have a screw gun with adjustable torque that will stop at the right tension. If you're paranoid about it , a blob of silicone sealant on the rubber washer will help ease your worries.

You can put the roof directly over rafters. I look up in my ceiling, the tin's right there. Every tin-roofed house I've seen in Australia does it like that. Smarter people put insulation under it - sarking, or you can get what looks like foil-coated bubblewrap now. Walking on it's fine, but try and step where the screws are or it will flex a bit. Horizontally on my roof, the screws are about 18" apart. Vertically, they're about 3 ft. It really depends on your rafter spacing of course.

There are advantages to steel roofs - impact resistance is one. A branch or (large) chunk of hail that will crack or go right through a shingle will merely dent a tin roof, if that. You can also make them highly reflective, which cuts down on the heat load in your house a lot.

I put a 5v metal roof on my DWs rental house down in FL. What a PIA! I've put up several pole sheds here in MN that used the flat rib panels. I've always used screws in the flats (I remember a long thread awhile back on the merits of screwing into the flats vs ribs ), as according to the manufacturers instructions.

The 5v metal ribs come to a very sharp point. There was no way you could get the self starting screws to start on a rib. In fact there was no way to keep a drill from wandering off the rib. I had to center punch and drill every hole. When going through a double layer the drill still wanted to wander when it hit the second layer, leaving an elongated hole in the first layer that I sealed with caulk. Because the ribs were so pointed you had to be very careful not to over tighten and tear the rubber washers. This was in a hurricane code area, I can't remember the spacing but it was a hell of a lot of screws. I'll never touch 5v again!

Just recently a BIL's father had a pole shed built near here. That crew used gasketed nails in the ribs rather than screws for the roof. They said the nails had a 50 year guarantee, longer than any of the screws. Like Beeman says, it's all over the map.

As for me I would like a metal roof, but I would go for one with a hidden fastener system, like the standing seam. There are getting to be more options out there though. Some metal roofs now look like shingles, some have an asphalt coating, etc, etc.

Personally, I don't know why anyone would pay all that money for a product and not follow the manufacturer's recommendations and requirements for screwing the product in place.

There is a reason that there are differing directions for placement and type of fastener between product manufacturers...they are different products!

Clearly, the manufacturer has tested their own metal product under varying conditions and come out with what works best for theirs.

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Our building came from:
http://www.freedomsteel.com/default.aspx

My walls and roof are all 'PBR' panels, the walls are 'fern green' and the roof is silver.



As you can see the hills have flat areas and the valleys have flat areas. But to drill the screws through the hills would not secure the sheet flush to the rafters. Driving screws through the flats of the valleys, then the screws can go directly through the steel rafters and they can be tightened so the sheet metal is tight against the rafters.

The manufacturer says:

Just to clarify, I did install the 5V according to manufacturers instructions, like bare said, I don't know why anyone would do otherwise.

This isn't the steel we used but the directions look similar: http://www.bentonmetaldepot.com/5V_install_guide.html

Just a quick note. This last fall a house not far from us caught fire and had a metal roof that had been put on top of several layers of shingles. The firefighters that we talked to said that part of the reason the house was lost was due to the fire getting those shingles going and there was no way to get to them to get water on them. They advised us (because we are planning on a metal roof in a few years) to remove the old shingles from underneath and start fresh with the roof when we start it. Not sure if this is accurate info concerning installation concerns, but we decided that is what we would do.

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Psalms 116:1-2 "I love the Lord, for he heard my voice; he heard my cry for mercy. Because he turned his ear to me, I will call on him as long as I live."

I had never seen a metal roof put on top over a pre-existing wooden roof. But that would make sense.

Mine is of course a metal roof, on metal rafters.

Steel is so much cheaper than stick-buildings, and structurally stronger [each building can be pre-engineered to the exact code: snow-load and hurricane forces of your state's requirements].

http://www.homesteadingtoday.com/sho...53#post1564253

Another post with a metal roof problem.

The problem with following the manufacturers directions is they are all over the map and extremely non committal.

Many of the metal roofs installed are being placed over existing shingle roofs. Again every manufacturer has conflicting info on how this should be done. Some recommend an underlayment over the shingles before installing the metal and others recommend wood strips over the underlayment. Most say either way so it just adds to the confusion.
As for screws the last manufacturer I spoke to said the screws will have to be replaced as the washers will fail. They said they used to recommend installing screws in the flats but had problems so they now recommend installing in the raised ribs. They said it really didn't matter to them as all they guarantee is the paint on the steel from peeling or fading. I guess all they will do is give you a new panel for the bad one and the labor is up to you.

I've also noticed quite a few metal roofs fading and peeling after a short time. Most noticeably red and green roofs seem to fade and peel the worst.

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"Education is the ability to listen to almost anything without losing your temper or your self confidence"
Robert Frost