Metal Roofing Old or New

[puffdog]

I have an old garage I use for storage and the roof has started to get holes in it . It has has fiberglass roofing on it now and I want to replace it with metal would you use the type they use to put on barns or would tou use the new stuff that they are putting on a lot of houses now ? Which would cost more ? When installing the new metal with screws do the screws go on the flat part or on the raised parts ? I ask two dealers and got to different answers . Thanks for the help have to start on it soon . :waa:

[Jackpine Savage]

The barn type will be much cheaper by far, that's what I would use for a garage. The screws go on the flats. Make sure you get the right type of screws. I've put up a couple barns and loafing sheds in the last few years.

[Ross]

There are different types of metal roofing, some use hidden fastener and some use the exposed head fasteners. Your sheet metal supplier should have an instalation guide Certainly all the barns and sheds here use either Security rib galvanised or Galvalume "Americana" pattern with or without the ridgevent system. All our types use the screws in the raised ribs with only the very occasional screw in the valley where absolutely needed.

[johnkl]

It looks like you're not gonna escape the two opinions here either. I'd use the screws on the raised part because if the gasket on the screw is not seat properly, the water will just run off the raised parts and would likely run IN on the lower, flat part. Regardless of how you do it make sure you use gasketed screws.

[Jackpine Savage]

I guess Ross probably has the best answer. Get the instructions for the particular roofing you get. That way they will stand behind it if you have problems. For the steel we get around here we are told to put them on the flats about 3/4" from the rib, even on the overlaps. Here's some generic instructions:

"Utilizing screw fasteners with neoprene and metal washers have an excellent sealing quality and are specifically designed for fastening in the sheet pan of trapezoidal rib metal roofing panels."

http://www.fieldshomeimprovement.com/ht_m_roof.html

"Ridges or flats? The panels are fastened to the deck or purlins with special-purpose nails or screws equipped with neoprene or EPDM washers, which compress beneath the fastener head to seal the puncture left by the shank. Nails--the fastener of choice in the days before reliable battery-powered screw guns and still used in some areas--should always be driven through the raised ridges between flats. Most roofs today, however, are fastened with screws, and while many installers also run screws through the ridges, manufacturers advise against it. Screws have lower shear strength than nails, which makes them vulnerable to breakage when they're left sticking out far enough to clear the ribs, and adequately tightening screws without crushing the ridge takes a delicate touch (Figure 2).

While it may seem counterintuitive to those used to fastening with nails, screws should be driven into the flats, at the spacing specified by the manufacturer."

http://www.findarticles.com/cf_dls/m...le.jhtml?term=

http://www.findarticles.com/cf_dls/m...le.jhtml?term=

[johnkl]

Thanks JS. Thats good to know.

[comfortablynumb]

yea put the screws in the raised ribs, if you screw then in the flat part as you may have to do in places, make sure you paint that part well with sealer, or squwoosh a bit of silicone caulk on it.
dont buy galvanized, i made that mistake and for a few extra pennies you can get the enamel painted ones that are warranted for 30? yrs. the galvanized arent warranted at all, and if you have acid rain (like we blessed PA people) they corrode fast.

[moopups]

The screws allways go in the raised portion. 'Ding' it and then punch a hole with a tapered punch, just big enough for the screw to fit. Do not mix steel and aluminum, this means not ever; static electricity will creat a situtation known as electroallise (sp), meaning the aluminum will corrode after a couple of years.

[shakeytails in KY]

Hey Puffdog- are you anywhere near Elizabethtown or Campbellsville? If so be sure to get your metal from B&W. You simply order it the exact length you need(like 14' 2")- and it's cheaper than getting it from any other source. I've gotten several thousand dollars worth of metal from them (in E-town) in the past 2 years. Last time I checked prices ranged from galvanized at 80-some cents a foot to #1 painted @ $1.50 ft.. They often have seconds and closeout colors that are quite reasonable in price as well.

For what it's worth, we use screws only- on the raised rib on roofs, on the flat for walls(appearance).

[Jackpine Savage]

I edited my post up above to add more of the explanation.

[Shrek]

The fiberglass coated tin, while costing a bit extra initally will be cheaper as its a 50 year roof. Bare tin wont last 1/3 te time of the coated . Also the coated tin looks much better and does not require painting .