Metal roof installation, materials, prices and manufacturers

Мetal Roofing Materials




As a supplier and installer of almost every type of a metal roof out there, including basic steel and aluminum roofing, and such exotic types as zinc, copper and lead roof we often had to face a choice of which roofing material to choose or recommend a customer. When it comes to choosing the right metal roof for your home, there are so many choices of metals as well as styles of metal roof that people may often be confused. So here I will try to clear up the confusion about different metal roofing types, galvanization methods of steel roofs and go over pros and cons of metal roofing in general.

Steel

The most common type of metal roofing material is Steel. It is the least expensive, readily available and very durable metal and is an excellent choice for construction industry. However, steel has some inherent “defects” – it easily rusts when is left untreated (bare metal) and exposed to the weather. Therefor, for use as a roofing material, steel must be first treated or galvanized with special coat of either zinc – commonly known as G-90 galvanized steel – or a mix of zinc and aluminum coating which is known as Galvalume. While the two methods are somewhat different, the both work very well and protect the steel from normal corrosion for as many as 50+ years.

G-90 Galvanized Steel:

G-90 galvanized steel involves taking bare steel metal – in coil or sheet metal and hot-dipping it in liquid zinc, As a result a layer of at least .9 0z of zinc is formed on the steel and will protect it against rust, corrosion and oxidation. The G-90 steel galvanization has proven itself as an excellent method of protecting the steel from rusting, even if scratched lightly or a field cut of the panel.

In our experience, the old left-over trim pieces of a Steel Shingles metal roofs that we installed and put the scraps in the bone-yard, where they basically lay in mud, and exposed to all the rains ans snow we get – there is not a single spot of rust when you pick any of the pieces up and inspect them.

As mentioned above, G-90 steel is used in Steel Single metal roofs by Tamko Metal Works, which we install in Massachusetts, Rhode Island and Connecticut. G-90 is also used in many other metal shingles products as well as by many Standing Seam manufacturers.

Galvalume – steel coated with zinc-aluminum alloy:

Galvalume is another excellent galvanization alternative, which is slightly more resistant to salty-air marine environment of the coastal areas. It is not completely immune to corrosion caused by salt in the air, but is more so than G-90 steel.

Galvalume is also know for its effect of “healing”. Healing is when the coating material is scratched, the coating next to the scratch or a cut, will “travel” to cover or heal the damaged area. This makes Galvalume steel and excellent choice for standing seam metal roofing, where long metal panels have a very high chance of getting deep scratches during installation process, because of their bulky size and relatively heavy weight.

Aluminum

Aluminum is the second most used metal roofing material behind steel. Aluminum has certain distinct advantages over steel, as well as some disadvantages.

  • Unlike steel, aluminum is much lighter, will nor rust (which makes it an excellent choice to be installed in the coastal areas) and is much easier to work with, for roof installers.
  • Steel is cheaper than aluminum and therefor more contractors install it. Aluminum is also not as strong as steel and you may need to use higher gauge metal when dealing with longer panels (35+ feet).
  • Another slightly unrelated disadvantage of aluminum VS steel is the fact that aluminum standing seam cannot be combined with UniSolar Thin Film PV laminates to make integrated Solar Metal Roofing assembly. Due to different expansion and contraction ratios of aluminum and the metal backing of the PV laminates, only steel can be used. This makes use of thin-film solar panels near the ocean, near impossibility (if you want to avoid delamination).

Despite more “bullet points” on the advantages side of steel roofing, in my opinion, aluminum is always a better metal to use, at it will certainly last longer than steel, price difference is negligible and the installation labor (before any company expenses, overheads and profits) may be more than cost of materials. With aluminum u do not need to worry about little scratches which may turn into big rust spots, and you can install it right on the ocean and not worry about corrosion.

Copper

Copper is a premium price and quality metal, and is rarely used anymore for complete re-roofs. Copper is mostly used for decorative purposes such as a roof on a bay window, or decorative trim, or as flashing for high end slate and asphalt shingle roofs. Copper roofs can be produced in a factory environment as well as on the job-site and installed by master craftsmen or so called “old-timers” with use of special tools for crimping, stretching and bending copper panels give the special shape.

Copper roof tiles can also be installed on very low slope and flat roofs, by interlocking them together and soldering all the seams. Though copper can be used for flat roof application it is too expensive and difficult to work with. There is also a higher chance of a roof leak if soldered seam was not properly cleaned and prepared of if tiles begin to expand ans contract too much.

Copper can also be stamped and take form of metal roofing shingles or tiles, and installed in a modular way, the same as steel or aluminum shingle systems.

Copper can be either pure or lead coated. When pure or bare copper is installed, it will begin to form “patina” or green oxidation layer. It takes a few years for copper to be fully covered by bright-green patina, and it does not affect the water-tightness of copper in any way. There are some reports lately, which say that copper life period may be shortened by the acid rains, but so far, copper roofs are known to last for centuries, and some are over a thousand years old.

Profiles

In my line of work I often see that people assume only one type of a metal roof: Standing Seam roofing, or vertical panels, locked together and fastened down with concealed fasteners. There are also other, similar systems to which most people also refer as Standing Seam, but it is actually not.

There are also numerous variations of corrugated steel panels and vertical rib roofing systems. These are installed with through-roof exposed fasteners and are not very well designed when it comes to trim details of sky-lights / chimneys and other curb penetrations. Even valley trim is dependent on the adhesives or a sticky tape. The corrugated and vertical panel metal roofs are also usually made from lighter gauge steel (usually no more than 29 ga.) and coated with cheap acrylic paints. They have a high chance to rust withing 10-15 years of installation and are not considered Lifetime Roofing systems

Corrugated and vertical rib panels are typically installed on a roof of farm buildings, storage barns, temporary structures, sheds, garages, and carports.  You as a homeowner probably don’t want to have it as a main roof over your house as the chance of leaks outweighs the savings over standing seam metal roof installation.

Advantages and Benefits:

Metal roofs are green, cool and long lasting roofing materials. They are usually made with high content of recycled metals and can be fully recycled at the end of their service life. Metal roofs are watertight systems designed to shed rain, snow and ice, before ice can form along the eaves, thereby helping to prevent ice dams on your roof.

Metal roofs add a great deal of aesthetic and financial value to your home, as well as make your neighbors very jealous :).

Having a new metal roof installed is almost the same as parking a new Ferrari in your driveway – only metal roof will actually decrease your homeowner’s insurance – not triple it. Metal roof will also greatly increase the comfort of your home, by reflecting most of the solar heat and will greatly reduce you cooling bills.

Written by Leo - roofer with a vision. Follow Leo on Google+






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Written by admin

November 1st, 2012 at 7:53 pm

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2 Replies to “Мetal Roofing Materials”

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  2. Robert says:

    Can you please send me an aproximate price to cover both sides of my home with solar/metal roofing, the aprrox sq/f is 1500 of the house so i would think it would be this sort of size

    thanks

    robert anstess



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