Options for Repairing Flat Roofs on Mobile Homes

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Water is the most damaging force on earth and your roof is the first shield of defense against it. Proper maintenance can help a lot, but even the most well-maintained roofs will eventually begin leaking. For traditional "stick-built" homes, a vast network of construction professionals and roofing specialists exists to repair damaged roofs or replace them when necessary. But owners of mobile homes, especially older models, have a different challenge since these roofs use a much different structure that calls for different materials and different techniques for repair and replacement. A homeowner who understands the different types of mobile home roofing can prevent home damage and potentially save a lot of money.

Three Designs for Mobile Home Roofing

Mobile and manufactured home roofs have been built with thee basic shapes through the years.

  • Mobile homes built before June 1976 typically have flat or bowed roofs, usually covered with sheet metal or asphalt coating.
  • Mobile homes manufactured after 1976 (generally known as manufactured homes) generally have more pitched, or peaked, roofs. They are often covered with traditional asphalt shingles or metal roofing panels, much like traditional frame-built homes. Structurally, the roofs are formed with standard trusses fabricated with a fairly shallow pitch.
  • Double-wide roofs use half trusses that become a single standard truss once the home is assembled. These roofs are also generally covered with standard roofing materials.

Solutions for Flat and Bowed Roofs

Repair and Seal

If your roof is bowstring or flat, it may have come with a metal roof. You are supposed to coat these roofs every couple of years or so, based on the manufacturer's recommendations.

There are misunderstandings about sealing a mobile home roof. Most people think sealing the roof will repair leaks, but that's not really the case. Sealing a metal roof helps do two things: It provides a reflective surface so the sun's rays are reflected, and it prevents the metal from rusting. While the process may help seal small leaks, these benefits won't last because the process is not intended for this purpose.

Before sealing, you will need to prepare the roof properly. The surface has to be clean and scraped smooth. Previous coats on seams and vents need to be removed with a grinder or steel brush to ensure that the new coating bonds well.

After cleaning the surface, and before recoating, you need to find the problem areas and seal them. Most mobile home repair professionals recommend a neoprene or polyurethane flashing sealant. Add it to the seams and around the vents and let it cure. Be sure to follow the manufacturer's instructions.

Once the flashing has cured, you will brush on the coating in layers. White elastomeric coating is recommended since it reflects sunlight. Be sure to follow the manufacturer's directions; some products require a preliminary primer before the sealer coat is applied.

Regular repair and resealing of a flat or bowed mobile home roof can extend the life of the roof can extend its life (every two or three years is usually recommended), but it is not a permanent solution. Eventually—as is true of all home roofs—the entire roofing system will need to be replaced.

"Roof Over" Solutions

Unlike a traditional stick-built home—in which the roofing surface is generally torn off each time a new roofing surface is applied—flat or bowed mobile home roofs that have begun to leak regularly often get a "roof over" solution, in which a new layer of roofing is applied directly over the existing roof. The existing roof should, however, be sanded, fixed, and sealed before applying the new roof. If the existing roof surface is in very bad condition requiring extensive repair work, then most professionals recommend complete removal of the old surface before the new roofing is installed.

There are three common roof-over options for flat and bowed mobile home roofs:

Seamless rubber roof: A seamless rubber roof is basically a thick coating of liquid rubber spread on the roof. Before the product is applied, the seams and vent flashing are sealed with a rubber neoprene product. Seamless rubber roofing is often applied by the homeowner.

Membrane roof: A variety of different flexible membrane materials can be used to overlay the existing roof. These are generally installed by professionals, not DIYers.

  • EPDM: Also known as seamed rubber roofing, EPDM (ethylene propylene diene monomer) sheets are stretched over the roof and bonded down around vents and along the seams. It is a classic roofing material for many flat-roof applications.
  • PVC: Thin sheets of polyvinyl chloride plastic are bonded together over the existing roof. PVC roofs have been around for many years and are considered quite durable.
  • TPO. Standing for thermoplastic olyolefin, TPO roofing is a single-ply reflective membrane made from polypropylene and ethylene-propylene rubber bonded together. It is typically installed so the layers fully adhere so that the white membrane remains exposed throughout the life of the roof. This is essentially a multi-ply reflective mat that is bonded directly to your existing roof or fitted onto a frame.

Corrugated metal roof: Regarded by some as the best option of all, installing a corrugated metal roof involves cutting and fitting sheets of corrugated roofing (available at home centers) onto wood battens installed against the old roof. Openings around vent pipes are carefully sealed with roofing cement. This is a fairly simple DIY project, and also a fairly inexpensive one. Many new roofs will cost less than $1,000.

Solutions for Peaked Roofs

Newer manufactured homes and double-wides with truss roof systems can be reroofed with some of the same materials used for flat and bowed roofs on older mobile homes. Shallow pitches can easily accommodate membrane roofing, but because pitched roofs are more visible, the preference here is often for more attractive roofing materials similar to those used for traditional homes. Thus, membrane roof-overs are relatively rare on peaked roofs, with metal and traditional shingles used much more often. Techniques for repairing and re-roofing are exactly the same as is used in traditional on-site construction.