BlogSpot.PK|The General Purpose Blog

DOW invented TPO Roofing in the early 1990’s. TPO Roofing means “Thermalplastic Olefin” roofing. TPO membranes are a combination of rubber and hot air welded seams made from ethylene propylene rubber. They are highly resistant to ozone, are algae-resistant, are eco friendly and safe to install. The material is often advertised as a monolithic (seamless) roof. TPO is highly tear resistant, resists impacts, and resists punctures with good flexibility to allow for building movement. TPO’s are available in white, light gray, and black with thicknesses of either 45 mils (.045″) or 60 mils (.060″). The width of the membrane depends on the manufacturer but they usually come in widths of 6 to 6 ½ feet and are 100 feet in length.

TPO Roofing is a fully-adhered roofing. In other words the roofing membrane is already attached to the substrate material with adhesive, thus it forms a strong chemical bond. TPO is highly heat reflective, fire resistant, and energy efficient. It also resists UV rays and dirt. TPO is used in the automotive industry where it is known for impact resistance. Because of the potential for hail damage this same property is important in the roofing industry.  

Another advantage of TPO, for the roofing contractor and manufacturers at least, is that there is a shift from some lower priced materials like EPDM to more expensive TPO materials. Commercial roofing sales reached $3.3 billion overall in 2007 with single-ply products comprising the largest segment. TPO has been expanding its portion of that large share.

As the green movement grows, TPO is becoming more and more popular, particularly because it is recyclable. Not only can it be recycled for roofing materials, but it can be burned as a fuel. TPO will burn extremely clean with no toxic emissions when no flame retardants are present. It therefore has a high potential as a high energy fuel for waste-to-energy programs.

TPO roofs are categorized as “cool roofs.”  A cool roof is defined in a variety of ways by people or by different municipal codes. But basically, a cool roof reflects and emits the sun’s heat back skyward without allowing it to pass into the building or home. The more sun it reflects and emits, the cooler the roof. The Cool Roof Rating Council, CRRC, maintains an on line database of cool roof products. Some TPO roofs score high on the scale, some do not, so be advised.

TPO roofing is the way to go for many .

Most homes have roofing shingles, but most homeowners don’t spend much time thinking about them. The purpose of roofing shingles are to provide a single layer solution to a leak resistant top for a home or structure. Roofing shingles are generally laid from the bottom of the roof, with each subsequent row overlapping the row below it. Traditionally shingles were made of wood and were capped at the top with a row of copper or lead sheeting. In modern shingle roofs this cap is replaced by a row of roofing shingles with plastic underlay.

In the old days wood roofing shingles were considered good. But eventually asphalt and asbestos cement replaced wood as common materials. Today fiberglass based asphalt shingles are the most popular roofing shingle used in the United States. Wood and paper backed roofing shingles have fallen out of use due to their lack or resistance to fire.

There’s another type of roofing shingle that many people have seen but few would be able to name. This roofing shingle is named a shake, which is a wooden shingle made from split logs. Shake roofs were common with log cabins, and with many wood frame homes. They’re still in use today, most commonly transported by helicopters, but it wasn’t always done that way. Before the invention of helicopters the shakes were tied into packs and transported by pack animal or even by human power. Often cut in hilly areas, they were carried down the slope with the help of a long line run from the bottom to the top. This line served as a kind of hand hold so people carrying the shake packs wouldn’t fall.

Many people wonder what is the difference between a shingle and a tile. Tiles are generally made from ceramic. They’re brittle and ill suited to locations where tree limbs might impact a roof. Shingles are flexible and therefor better able to stand up to tree limbs. Wood shingles rot, while ceramic tiles don’t, but modern materials such as the asbestos base for most shingles don’t rot. Another difference is the shape. Shingles are flat, while ceramic tiles commonly have an “S” profile to allow them to interlock for strength.

Believe it or not slate is also used for roofing shingles. Because of both cleavage and grain slate can be easily split into thin sheets. Such sheets, the slate roofing shingles, make for an rustic look for a roof. Slate roofing shingles are installed by a slater, a tradesman trained to work with slate. Because slate is fireproof and an electric insulators, qualities that make it excellent for roofing shingles, slate was used for early 20th century switchboards and relay controls for large electric motors. Imaging making a phone call on your roofing shingles.