The Affordable Stainless-Steel Roofing System: The Affordable Stainless-Steel Roofing System lays stainless-steel sheet-metal laterally across the roof with side-laps down the roof. The lateral sections are about 25' long and then the end-laps are about 12" to 16". The width of the stainless-steel sheet metal is about 16" to 20" and the side-laps are 3" to 4". The stainless-steel sheet-metal attaches to the roof deck with stainless-steel roofing nails in slotted holes or with stainless-steel wood screws in slotted holes. Of course the roofing layout begins at the eave and works upward to the ridge.
The Stainless-Steel: The stainless-steel sheet-metal is found in coils and bought by the pound. This stainless-steel sheet-metal is raw material without any fabrication or flattening. This stainless-steel sheet-metal has a thickness of about 0.028" to 0.030". Then 430 stainless-steel has almost as much corrosion resistance as 301 to 306 stainless-steel but has less thermal expansion and costs less. Or 316 stainless-steel has the most corrosion resistance and costs the most. Well, 301 to 316 stainless-steel should be used at the ocean, used around chemical plants, and used at the curb when there is road salt but otherwise 430 stainless-steel might be good enough. Next, consider stainless-steel finishes with BA and #8 too bright. However, there is one project with BA finish surrounded by trees and on elevation above the road. (The 430 stainless-steel can make a rust line where nicked with a cut-off disk or where a crease is overworked. However, a grinding wheel touch usually doesn't rust.)
First Set of Details: The first course along the eave has two to three inches overhang but is attached to the roof deck with slotted holes near the eave edge of the roof deck. Then another course goes over and both courses attach to the roof deck with slotted holes near the back edge. Finally, both courses at the eave rivet together over the ground with stainless-steel closed-end pop-rivets. This two-layer installation technique makes hold at the eave.
Second Set of Details: The roof-courses-ends that overhang the ground at the gable have their side-lap riveted with stainless-steel closed-end pop-rivets and that at the point where they do overhang the ground. If concerned about differences in lateral thermal expansion between top-of-roof and bottom-of-roof then small stainless-steel bolts in loose holes can be used instead of water-tight rivets. Of course that's leaking bolts over the ground at the gables but bolted together side-laps.
Successful Roofing: The section end-laps lay flat if the stainless-steel sheet-metal is not kinked and if the ends are cut correctly. A hand-held metal-cutting power-shear for cutting straight lines works well enough. Similarly, the course side-laps lay flat.
Advantages of the Affordable Stainless-Steel Roofing System: The stainless-steel roofing does not need painting and will not rust or corrode. The stainless-steel roofing maintains its advantage over corrosion even where cut or drilled. The stainless-steel roofing is very durable. The stainless-steel roofing is light in weight at about 1.25 pounds per-square-foot. However, more weight advantage is because of a small percentage of side-lap and end-lap area. The stainless-steel roofing can be touched-up through the years with the use of a handheld power grinder.
Problems with the Affordable Stainless-Steel Roofing System: The natural ventilation of the side-laps might favor summer over winter. The side-laps hold moisture for a few hours after a rain ends.
System for a Warped Roof: The stainless-steel sheet-metal can easily conform to a spacer system and so also consider this roofing system for use on warped roofs. Then a 16" grid of spacers can be cut from the ends of 4-by-4's. In fact, cedar is light in weight and strong enough to support a roof covering. A point of no roof warpage has a spacer about 1.5" tall while roof points with warpage have spacers cut to height measure. Now, a grade-matching laser can set spacer heights along the eave and along the ridge. Then a 24' long 2"-by-3" aluminum rectangular tube can be used to measure for spacer heights between ridge and eave points. The slight and natural bend of the aluminum beam makes smooth transistions between the spacers. In fact the resulting grid of spacers is so close to perfect that standing-seam roofing might work on them. Note that the roof spacers can be attached to the roof with wood screws in deep counterbores.
Useful Tools and Materials: Stainless-steel #8 wood screws can be found most affordably in square-drive truss-head type-17-point. Various lengths are available up to 2 1/2". Of course, countersink screws are avoided since screw head edges are used for holding. Both underlayment nails and roofing nails are affordably available in stainless-steel. A 12" sliding miter saw can cut 4-by-4's. A 1 1/2" straight die grinder (1/4" collet and 25,000 RPM) at about 3 amps power can cut slots in sheet metal using 2" diameter cut-off wheels and working between drilled holes. There are three types of handheld power sheet-metal shears. One type cuts mostly straight lines, another type cuts straight lines and curves of several inches in radius, and a third type that can cut tight curves. Technique and cutting angle must be close to perfect. Forstner bits will drill counterbores in wood height spacers. A three-plane leveling and alignment laser mounted on a photographic tripod with a geared head can match grades. Or a 24' long 2"-by-3" aluminum rectangular tube can be used for level or grade. A 2 1/2" to 3" brushed stainless-steel tube in 0.125 thickness can mount TV antenna or satellite antenna but also be a weak ground for the stainless-steel roof. The idea of grounding a metal roof is to avoid a build-up of static charge. A roof-top lightning-rod system is a completely different fundamental since it would be insulated from the roof. (A metal roof can also be grounded to the fuse box ground with copper or aluminum wire.) Stainless-steel closed-end pop rivets have a wider spec grip range in 3/16" diameter than in the smaller diameters. A two-hand lever rivet tool at about 20" in length can easily set the rivets. Also, sized stainless-steel washers are available for stainless-steel rivets. A power drill at about 4.5 amps and with an adjustable clutch set at about "7", can set #8 wood screws tightly but without cracking the wood. A drill press can be set up to drill counterbores in wood spacers to a set depth. Simple handheld metal bending tools can make short simple metal bends. Premium drill bits are easy to find but a sharp drill bit is critical for rivet holes. Drilling in steel should be at slower speeds than wood and should bite and flake immediately and hold in punch marks. Rivet holes also require a reamer operation.
Newest Tips: A length of stainless-steel sheet-metal can easily be pulled up on the roof using lumber as an incline plane. Getting a length of stainless-steel sheet-metal off the coil is done with a re-rolling action such that the outside of the coil becomes the inside of the coiled length taken off. That's with the coil on its side and the worker working around the coil. The length of one coil revolution is Pi-times-outside-diameter. Then after the re-roll is unrolled a measuring tape is taped to the length every 6" to 12" and exact cut-off length marked. Or a very long length of stainless-steel sheet-metal can be cut-off, coiled, set on a pallet, pulled up on the roof, and then uncoiled.
Additional Notes: Additional or alternative roofing hold-down can be built with stainless-steel square tubes, about 1 1/4" square and 1/8" wall thickness, laying on the stainless-steel roofing and runing up the front of the roof and down the back of the roof. Then the stainless-steel square tubes attach to each other at the ridge and attach to the faceboard, or to vertical pieces dropping to footings in the ground, at the eaves. This hold-down structure, if used, is at the gable-ends and at the section end-laps. Another method of roofing hold-down is to solder the side-laps with silver-solder every 12" to 16". (Both riveting side-laps at the gable-ends and soldering side-laps all across the roof run the risk of tieing the thermal expansion of the top of the roof into the bottom of the roof. But the roofing thermal expansion is mostly with the lateral strips with just some amount of variance from top of roof to bottom.)
Ridge Note: The ridge piece completely overlaps the course near the ridge such that the ridge-piece can bolt to the top layer of the course side-lap. The ridge-piece is bolted with upside-down stainless-steel bolts such that the leaking connection only has to drain about one inch out from under the course side-lap. Of course, the ridge-pieces are also end-lapped to each other. The ridge-pieces are four to six feet long and are made in a brake from stainless-steel sheet-metal that is cut to size and flattened. A hip works similar to a ridge except that a hip intersects the course layout instead of running with-it. So a hip-piece bolting to the edge and top layer of a roof-course side-lap should be with a slotted hole in the hip-piece with the slotted-hole in the direction of the roof-course thermal expansion. Next, a valley is like an upside-down hip except that the course-ends reach over the valley-piece and don't have anything to attach-to.
Another Tool Note: Affordable straight sheet-metal brakes can be found in four-foot and six-foot lengths. These metal brakes can make ridge pieces of four to six feet long and can make face-board drip-edges of four to six feet long. Now, pieces of sheet metal to be bent at the halfway point of their length, and attached only at their length ends, should be flattened sheet metal. Basically, ridge-pieces, hip-pieces, and valley-pieces are expensive because they require stainless-steel sheet-metal that is cut to size and flattened for use in the brake.
Another Material Note: Any metal fastener or flashing touching the stainless-steel roofing should also be stainless-steel or it will corrode. A stainless-steel roofing nail with stainless-steel washer holds the stainless-steel roofing on the roof deck with the nail in the slotted hole. Well, the stainless-steel roofing nail lays flatter than a stainless-steel wood-screw but a stainless-steel wood-screw has more hold. Of course the roofing attachment to the roof deck is under the side-lap after the roofing is installed. The roofing-course attachment to the roof deck is every 16" across the roof. Also, when this paper mentions bolting stainless-steel sheet metal it is refering to the use of #8-32 stainless-steel machine-screws with stainless-steel washers and nuts. Now consider the section end-laps such that soldering of the side-laps should not tie the section end-laps together and bolting of the ridge-pieces should not tie the section end-laps together. Finally, a roofer with coils of stainless-steel sheet-metal does have the option of renting a portable standing-seam forming machine and building a panel-roofing instead of a lateral-strip roofing.
KBH: KBH of metro Atlanta, GA is a software application developer and an inventor and designer. KBH also owns KBH Applications. Contact is through the e-mail listing on this web page.