Metal roof installation, materials, prices and manufacturers

Archive for the ‘Metal Roofing Materials’ Category

Standing Seam Metal Roof Guide

with 22 comments

Standing seam is the most popular style of metal roofing – both in residential and commercial building industries. It has also been the longest installed type of metal roofs, dating back to when all metal roofing was hand-made from sheet metal – usually copper or tin.

Image of standing seam metal roof

Today, standing seam metal roofs are commercially manufactured by tens if not hundreds of big metal roofing manufacturers, and thousands of smaller roofing outfits with their own sheet metal shops and standing seam rolling machines. Here is how standing seam metal roof is manufactured.

We recently added a complete installation guide that walks you through preparing a roof deck and installing roofing underlayment, installing eave, first metal roof panel with gable / rake trim, field panels, sidewall flashing, valley flashing and installation of hip & ridge caps, and includes a hands on metal roof installation video.

Most standing seam metal roofs installed today are 24 gauge steel or .032 aluminum panels with high quality Kynar 500 paint coating, baked on in seven layers (including primer) in the controlled factory environment when the metal coil is manufactured. After the coil is slit to the right size, it is delivered to the “manufacturer” of metal roofs, and is roll-formed into pre-measured length panels, either on site or in the metal shop, and then delivered to the job site, where they are installed on the roof.

Most common profiles of standing seam roofs are 16″ panels – either snap-lock or mechanical lock profiles. Snap lock allows the metal roofing contractors to quickly install the roof by snapping one panel into receiving the lock of the previous panel.

Snap lock panels can be installed from left-to-right or vice versa, or even from a center starter panel in either direction.

Standing seam metal roof installation

Standing seam metal roofs should be installed over a properly prepared roof deck. The wooden substrate below should be even, dry, and be at least 1/2 inch thick. Standing seam roofs can also be installed over purlins (horizontally running 1×3 or 1×4 furring strips) or over boars. It is also recommended to install standing seam metal roofing over a roofing underlayment such as roofing felt (tar paper) or synthetic underlayment. It is recommended that synthetic underlayment is breathable, so it does not trap moisture, which can cause the roof deck to rot and mold / mildew can form, causing expensive repairs. Ice $ Water shield is also not recommended for use under a metal roof, as it is first – not serving it’s main purpose, since metal roofs inherently prevent ice dams, and Ice and Water will also trap moisture.

In Norther New England states (NH, VT and ME), it is a common practice to install a standing seam metal roof over asphalt shingles. This is done mainly for economical reasons, as roof tear off and disposal can be very costly. This practice should also be avoided however. Two reasons for this are:

  • Standing seam panels will expand and contract with temperature changes, while the under-pan will be rubbing against the stone-coated surface of asphalt shingles, which will strip off the paint and galvanizing layer of the metal roofing panels and cause rust.
  • When snow sits on a metal roof, it compresses the panels against the asphalt shingles, creates horizontal dents on the panels, which make your new roof look very unattractive or should I even say – ugly. This is also referred to as “telegraphing effect”, when rows of shingles show through the metal roof.

A standing seam metal roof is attached to the roof deck using fasteners (usually 1 inch wide head screws) and either clips or screws / nails installed through a nailing strip, which can be formed when the metal panels are produced.

Nailing strip panels are faster and cheaper to install, but should not be used on panel runs over 15 feet, as expansion and contraction will cause buckling and “oil-canning” in the panels. Oil canning is a term used to refer to ugly bubbles that you can sometimes see on a standing seam roof. To prevent oil canning, you can have your standing seam metal roof made with special low profile stiffening ribs that are indented into the pan of each panel, during manufacturing process.

Another way to avoid oil canning is to install the standing seam roof using clips (this reduces the tension on the panel) and to install panels in mild weather, so it’s not too expanded or contracted at the time of installation, and of-course you need a more or less even roof deck surface.

Pros and Cons of standing seam

While standing seam roofs are very popular, they are rather difficult to install on complicated roofs, with many dormers, skylights, valleys, etc. They can be very pricey compared to other metal roofing materials such as metal shingles, shakes and stone coated steel roofing profiles. The difference in cost is mainly due to the difficulty of installation, high waste factor, and higher material cost for quality metal roofing panels (not the 29 ga cheap steel, acrylic-coated metal roof normally installed by low-ball metal roofing companies).

Because of the design of architectural standing seam metal roof, it is also very difficult to install a roof penetration flashing for sky-lights and chimneys, as there is no one good flashing method, and you rely mainly on caulking, when it comes to water-tightness. All of these factors complicate the installation process of standing seam metal roofing and make the cost go up.

Standing seam on low slope roofs.

A standing seam metal roof can be installed on a low slope roof of no less than 1 in 12 pitch. It must be a mechanical lock standing seam system, and is usually a structural standing seam, installed on space metal buildings.

The mechanical lock profile used on low-sloped metal roofs ensures that water does not penetrate through the lock between panels, if it sits above the lock. Structural standing seam is often made of cheaper steel with low quality galvanic coating, and can begin to rust within 10-15 years, and will require a roof repair, as well as fastener re-tightening.

Metal roofs should never be installed on dead flat roofs as it is not designed to withstand ponding water and all joints on a metal roof are sealed using some type of caulking. Even the copper panels with soldered seams have proven to leak on dead zero slope roofs. Most interlocking shingles profiles can only be used on roofs with at least 3 pitch. As for standing seam, it can be used on very low slope roofs, but you must use the mechanical lock profile to prevent roof leaks.

Written by admin

November 1st, 2012 at 9:45 pm

Environmental Benefits of Steel Metal Roofing

without comments

Not only are steel roofs 100 percent recyclable, they are often made from recycled materials, unlike traditional roofing. Because metal roofs are so lightweight compared to other roofing materials, when a new steel roof is installed, it can be placed over the existing roof. This can provide the double advantage of insulation and eliminates the need to remove the old roof, minimizing waste taking up limited space in our landfills.

Metal roofs are included on the U.S. EPA’s Energy Star Roof Products Program because of their environmental benefits.

Metal roofing can reflect up to 70 percent of solar rays. High reflectivity allows the roof as well as the rest of the building to stay cooler. Cooler roofs translate directly to savings for homeowners. A study performed by the Oak Ridge National Laboratory found that reflective roofs save up to 40 percent in heating and cooling energy costs.

Reducing energy consumption means less fossil fuel is required to power the heating and cooling needs of homeowners, and that fewer greenhouse gases are released into the atmosphere.

According to Oak Ridge National Laboratory research, “Metal roofing retains solar reflectance over time better than other roofing products because it resists the growth of organic matter and sheds dirt more readily than other roofing materials”.

It was also found that metal roofs “maintain their energy efficiency better over time than any of the other roofing systems studied.” Metal and steel roofs are some of the most durable material available, making it also one of the longest lasting. Over its life, a steel roof continues to save energy – and money – paying for itself in as little as nine years.

Steel roofing is the sustainable option. A traditional built-up roof often must be replaced every nine to seventeen years, whereas a steel roof can last 30 years or longer. The waste from other roofing materials, such as asphalt shingles or concrete, has nowhere else to go but the dump. There are millions of tons of roofing waste generated every year that ends up in the landfills, and this waste can be drastically reduced, if homeowners begin installing longer lasting cool metal roofs.

Note: Aluminum roofs can last over 100 years, as they are not subjected to rusting, which can dramatically shorten the lifespan of a steel roof. However, modern steel metal roofing uses high-grade galvanized steel (G-90 steel or Galvalume), which is much more resistant to corrosion and rust. Also the high quality Kynar 500 metal roofing paint provides additional protection for steel metal roofing panels. G-90 and Galvalume coated metal roofs can last as long as 50 years or more. Only the low grade / gauge steel roofing (26 ga) with acrylic paint are expected to last 20-30 years before they begin to rust. These panels are usually used in less expensive exposed fastener roofing.

Popular metal roofing styles:

  • Standing Seam Metal Roofing – vertical panels with concealed fasteners, made using steel, aluminum, zinc, copper and other metals. Architectural standing seam roofs offer an aesthetically pleasing look combined with lifetime roof performance, resistance to ice dams and reduced heating costs.
  • Metal Roofing Shingles provide lifetime roof performance combined with many styles – these can look like natural slate, cedar shakes and shingles, concrete tiles, etc. Metal shingles come in smaller form factor, and therefore can be made from thinner metal, while maintaining structural strength and rigidity of bigger standing seam panels. Thinner material allows metal shingles to be less expensive than standing seam roofing, and they are also easier to install, reducing the overall installation cost.

Written by admin

November 1st, 2012 at 2:15 pm

How a Metal Roof Is Made

with 4 comments

When you see that sparkling new metal roof up on your house, or a home you drive by, do you ever think about how this metal roof was made and what goes into the manufacturing of metal roofing materials?

Image of standing seam metal roof

A standing seam metal roof is the most popular of metal roofing materials, in part because it can be manufactured by the roofing contractors on the job site, or in a sheet metal shop, to the exact specs provided by the contractor. You don’t need to “deal” with big manufacturers when getting a standing seam metal roof. But lets take a step back and actually explore the manufacturing process of a metal roof, from the iron ore mine to your roof.

Roll-forming Standing Seam Metal Roof

All standing seam metal roofs go through a roll-former – a machine that turns a metal roofing coil into actual metal roofing panels. The roll former machines can be outfitted with different panel profiles, mechanized or manual shears, computer controller unit, portable or stationary platform / trailer, uncoilers, built in 10000 watts generator, and other upgrades, depending on the purposes of it’s use and how much you want to spend.

Image of Standing seam metal roof roll-forming machine

The basic process of making a standing seam panel involves feeding the metal roofing coil into the roll-former, which then goes through a series of rolls, which make bends and curves. Each next roll makes more of a bend than a previous one. These rolls are made of hardened stainless steel for increased life span and durability. Some can bend a metal as thick as 22 gauge steel.

The rolls make up different standing seam profiles, such as Snap-Lock standing seam, Snap-Lock with a nailing strip (no clips required, when fastening the metal panels to the roof), Mechanical Lock Profile, R-Panel, V-5 Crimp panels, and many more exotic profiles of corrugated and standing seam metal roofing.

A panel width can be manually set on each roll-forming machine, but typical widths are 12, 16 and 20″ wide panels. Panel width is actually dictated by a metal coil that you use to make your metal roof. For a 12″ wide panels you need a 16″ coil. The “extra” 4 inches are not shaved off inside a machine – they actually go into making the locks on each side of the panel.

The computer control unit takes care of the machine operation / speed, panel length, etc. A smart control unit with automatic shear, can pretty much automate your manufacturing process, by running the panel at specified speed and cutting them at specified length. For example you program it to produce 10 panels at 28′ 3″ and 25 panels at 24′ 6″ and it will do just that – at required length, the machine stops, the automatic shear cuts off the panel, you pull it out and the next panel starts rolling out of the machine.

Sheet Metal Shop

Besides the actual metal roofing panels, there is also a lot to manufacturing a metal roof that escapes the eye – namely, making all the accessories for the metal roof: the drip edge, rake / gable trim, valley pans, ridge cap, z-bar flashing, sidewall and head-wall flashing for roof to wall connection, chimney and skylight curb flashing, etc. All of these items require precision manufacturing and are absolutely necessary for any type of vertical panel metal roof.

All these metal roof flashing is made in a sheet metal shop, on highly sophisticated, computerized sheet metal brakes, which can also be programmed to increase the speed of making the most popular profiles of metal roof flashing.

The way that a computerized brake is different from a manual or a hand brake is that when using a manual brake you have to manually measure, mark and set up the depth for each bend to happen, and you have to do it on each side of the metal strip to be bent. While this is a viable option, it is very slow, labor intensive and not very precise.

The computerized or automatic sheet metal brake, which is a necessary attribute of any good sheet metal shop, has special “fingers” or stops that will let you insert a strip of metal only so deep inside the brake, and the hydraulic bender, will make the bent. These computerized brakes are very heavy duty and can easily bend metal that is 22 gauge or thicker. Even a 3/16″ thick metal (aluminum and steel) can be bent in a heavy duty industrial brake, but for metal roofing it is an overkill, as typical thickness rarely exceeds 24 gauge metal in residential application and 22 GA. in commercial metal roofing.

Besides a sheet metal brake, a metal shop needs an automated hydraulic shear to cut strips of metal to the required width, so that the brake operator could quickly produce required components and not worry about having the pieces of metal cut.

Beside the shear, the break, and other smaller specialty tools, each sheet metal shop has heavy duty racks, where the metal coils, sheets of metal and already produced flashing accessories are stored, and a fork-lift to load and unload all the coils and other heavy stuff. Shop workers cannot lift a typical 2000-3000 lb. metal coil on their own.

Image of Sheet Metal Shop

The bottom line is that running a metal roofing panels manufacturing facility is quite costly, and all work must be coordinated between the guys that make the panels and the sheet metal shop. Most of the time, to simplify things, the roll-forming machine is located in the shop, on the transportable trailer, and is only taken to a job-site when the job is far from the shop, and panels are too long to be transported by conventional means.

Often,metal roofing contractors who own a roll-forming machine, and manufacture their own standing seam metal roofs, employ an independent sheet metal shop to produce their flashing and accessories, as running the fully equipped shop can be afforded only by bigger, commercial size roofing contractors.

Manufacturing Metal Roofing Coil

We will actually skip the process of converting iron ore into iron / steel, processing and purifying it, etc. We will start with manufacturers of metal roofing coils, and what they do.

First of all, metal roofs can be made not only from steel – aluminum, zinc, copper and even stainless steel are all used in metal roofing industry. However, galvanized steel and aluminum are the most popular metals, and we will concentrate on these two.

There are about four or five large suppliers of metal roofing coil in steel, and two or three in aluminum, with smaller players picking up the slack.

Image of Metal Roofing Coil

All of these guys basically take a thick metal coil, and run it through rolling machines, to reduce the thickness to a required grade – usually 29, 26, 24 and 22 gauge in galvanized steel, and .032″ / .040″ in aluminum. The steel coil also undergoes the hot-dip galvanization process, where the coil runs through a pool of boiling galvanic mix of molten zing (G-90 galvanization) or a mixture of zinc and aluminum (Galvalume). Once the coil is dipped in the hot galvanic metal, a thin galvanization layer is formed all around the otherwise highly corrosive steel.

Then the coil is run through an annealing machine, which is basically a hot furnace with cooling tubes and ammonia gas inside the chambers. Annealing softens the metal, which can then be easily rolled down to the required thickness. Aluminum coils do not require galvanization and just go through an annealer machines and then get rolled down.

Applying Metal Roofing Paint (Kynar 500) is done once the metal coil has been galvanized and cleaned. The coil is then fed into a special “painting machine”, which is a series of separate units, each responsible for it’s own operation. First, the coil is thoroughly cleaned and dried. Then it goes through a primer application chamber, where primer is applied to both sides of the coil. Then it goes through a baking chamber where the coil is dried at a high temperature, and primer is baked on. Then another primer and bake-on drying process happens for better, more even primer application.

Once the coil has been primed, and primer has cured in the “baking” chamber, it goes through the painting cycle, which is essentially the same as priming, only the main color is added to the coil in two layers on top. Usually a white coat is added to the underside of the coil, which once again goes through the baking / drying cycle.

Manufacturers

Once the coil is painted, it is shipped to metal roofing manufacturers such as Englert, MBCI, ATAS, etc. These guys slit the coils to their standard widths and cut them into smaller coils – usually 1000-3000 lbs. instead of huge 10000 lb. coils, which come from coil manufacturers.

These smaller coils are then either formed into different types of metal roofing panels and sold off to smaller sheet metal shops / contractors with roll-forming machines, who either install them, or resell them to metal roofing contractors.

The bottom line here is that most standing seam metal roofs and other metal roof materials are virtually the same product, as most of them use standard Snap-Lock or Mechanical Lock profiles (under different names of course), and the coil usually comes from the same p3 or 4 places. The difference is in price, warranty and Manufacturer-specific custom panel profiles.

Other than that, as long as the coil comes from a household-name supplier, it does not matter who produced your metal roof. What really matters is the quality of installation.

And yet, I myself have seen aluminum metal shingles with chipping and peeling paint. On one roof made by a company out of Canada, each shingle had paint peeling off at exactly the same spot as others, which leads me to believe that the coil was not painted properly on one side. Another example is of another, smaller metal roofing shingles “manufacturer” out of Canada, whose aluminum metal shingles would also lose paint, and paint would easily come off when scratched with a finger nail. This manufacturer would not warranty the product, and stopped responding to the complaints of the homeowner.

These two examples indicate that warranty is still important and you want to have your metal roof come from a respectable company that will honor their warranty obligations. Just to give you peace of mind, these cases with paint defects are EXTREMELY rare, and most steel metal roofs (especially cheap 29 ga. steel with acrylic paint) will rust before the paint comes off. So it’s more important to buy a premium product, if you want a premium service out of your metal roof.

Written by admin

November 1st, 2012 at 1:56 pm

Metal Shingles Roofing

with 9 comments

Metal shingles roofing systems are a very popular choice for a residential metal roof, and although they are not as common as standing seam metal roofs, they nevertheless represent a significant chunk of the total number of metal roofs installed each year.

Metal roofing shingles come in many styles, colors and metal options and profiles. Two of the most common types of metal shingle roofs are interlocking shingles and overlapping tiles. Metal roofing shingles are true architectural metal roofs, and can provide you with a long lasting roofing solution and looks of natural slate, clay tiles or cedar shingles at a fraction of the cost and a much longer roof life.

Image of Metal Shingles Instillation

Metal shingles vs. Standing Seam Metal Roof & other Roofing Materials

Most interlocking metal shingle roof systems are also VERY flexible when it comes to installation and can be adjusted for the most difficult and cut-up roof designs. You can easily roof around a hexagon tower with metal shingles, while the same would be nearly impossible to do with standing seam metal roofing panels.

Flashing a roof penetration such as a pipe flashing or even sky-light or a chimney is a breeze compared to the same procedure using standing seam or stone coated steel tiles roof. Because of low panel profile (average interlocking shingles metal roof sticks about 1/4″ to 3/8″ from the roof deck) metal shingles flashing is easy to fabricate and install in the field.

Chimney flashing installation video on a metal shingles roof

As you can see in the video above, the chimney flashing (as well as skylight flashing) on a metal shingles roof is rather simple, compared to that of standing seam metal roof, which you can see in the photo below.

The chimney flashing photo below shows a standing seam metal roof with a chimney located on the ridge line, which makes the flashing detail much simpler and eliminates the back pan flashing, which is the weakest point of this flashing detail.

Chimney flashing on standing seam metal roof:

The elimination of ribs (vertical snap-lock on standing seam metal roofs) makes the flashing detail using metal shingles for both chimney and skylight, a breeze.

How metal shingles are manufactured

Metal shingles are made in factory settings using a stamping manufacturing process on an industrial size press. A special dye stamps the metal shingle profile, while two additional dyes bend the locks on all four sides of the shingle.

Metal shingles are stamped from a steel, aluminum or copper coils of certain thickness. Steel and aluminum coils are usually painted with 7-layer bake-on Kynar 500 metal roofing paint, which provides the longest lasting discoloration and peel/chip resistance and eliminates the need to paint your metal roof every 5 or so years.

All accessories for a metal shingles roof system are made using either a rolling or bending process on a computerized brake. These are your drip edge, side-wall / head-wall flashing, valley pan, etc. The ridge / hip caps are usually also stamped out of the same coil used to stamp shingles. A 10 foot field-fabricated ridge-cap section can also be used, with exposed of concealed fasteners. Check out this article for more info on how metal roofing is manufactured.

Metal Shingles Roof Installation:

Metal shingles should be installed over a solid sheeting deck such as CDX plywood or OSB board and proper underlayment such as GAF DeckArmor breathable synthetic roof underlayment. Try to stay away from non-breathable underlayments and Ice & Water shield with metal shingles roof, as they trap moisture and may cause roof deck rotting.

If your deck is 1×6 boards or similar, you may run into problems with installing and nailing metal shingles. If the row of shingles lands on the crack between boards, your nails will not have a solid substrate to be nailed into. Solution in this situation may be using longer clips, that extend past the crack between the boards, or installing a layer of 3/8″ plywood or OSB over the boards. Using long clips will however result in weaker fastening and lesser pullout / wind uplift rating for the metal roof. Installing a layer of 3/8″ sheeting is a preferred method.

Metal shingles are fastened to the roof deck with nails and either clips or built-in nailing strip on the metal shingle. There are various types of metal shingles and each has its own fastening method, though they are rather similar to each other.

Metal shingles should be nailed to the roof deck, using nails made out of the same metal as the shingle. Thus a steel metal shingle is nailed with regular galvanized roofing nails, and aluminum metal shingles are nailed with aluminum ring-shank nails.

Metal shingles are installed from the bottom, going up. Direction of shingles placement is dependent on the shingle design, but most metal shingles systems are installed from left to right. Each metal shingle is locked into the locks of 6 neighboring shingles, making the whole system very durable and resistant to high-speed winds.

As shown in the video above, an aluminum metal shingles roof is installed over a properly prepared roof deck, and nailed down with aluminum ring-shank nails, through special “ears” or nailing strip built into the metal shingle. Other systems will have different nailing detail such as clips, or a nailing strip going across the top of the shingle.

Metal Shingles Roofing Materials and Prices:

Metal shingles roofing is usually made from steel or aluminum, and on a rare occasion you will see a copper or zinc metal shingles roof. The reasons for using steel and aluminum are the facts that both metals are very durable and long lasting (assuming the steel is properly galvanized using G-90 or Galvalume coatings). Steel is somewhat cheaper than aluminum, but difference is not very significant, and much of roof installation cost comes form professional installation as well as a rather high cost of metal.

Copper and zinc metal roofs are generally very expensive and therefore not as popular as steel or aluminum roofs. Installation costs for either type of metal roof will vary from one region to another, but in general, metal roofing prices are much higher than asphalt shingles roofs.

As compared to the cost of standing seam metal roofs, metal shingles shingles are considerably less expensive, as they are made from thinner gauge metal, and are easier to install.

Written by admin

November 1st, 2012 at 10:22 am