A POLYURETHANE FOAM ROOF
FOR OUR MOBILE HOME
at Solar Haven
Every house needs a good roof, particularly mobile homes which never come with one. Not only do mobile home roofs leak eventually, but worse they are so poorly insulated that higher heating and cooling costs and an uncomfortable interior are always the result. Replacing the roof entirely with heavier metal sheeting and insulation was prohibitively expensive as was building a new A-frame structure roof over the whole mobile home itself. A layer of polyurethane foam was expensive too but seemed the best compromise.
The $1950 we spent for a two inch polyurethane foam coating on the roof of our single-wide mobile home turned out to be one of the best investments we have made. The mobile home is so much cooler inside and requires much less use of our evaporative cooler. (We have a back-up 5000 BTU room air conditioner, but have not had to use it.)
The foam is sprayed on under pressure and cures immediately into a hard surface you can walk on without damaging it. Older polyurethane foam roofs apparently used to get big air bubbles in them which were unsightly and would break if walked on. Also the woodpeckers put holes in the roof with no trouble. These problems have been eliminated with the newer types of foam used today. The surface is completely waterproof, seamless, good looking, and provides an R value of 15 for the two-inch coating we used.
ADVANTAGES OF SPRAYED POLYURETHANE FOAM (SPF)
Highest "R" Value - SPF has an "R" value of 7.14 per inch enabling it to provide more thermal resistance with less material than any other insulation.
Seamless - SPF forms a seamless insulated roofing system. Whether a roof is 10,000 sq. ft., 100,00 sq. ft or larger in size, it will have no seams.
Eliminates Flashing Leaks - SPF is ideal for flashing parapet walls, roof penetrations and roof mounted equipment, including vents, pipes, stacks, HVAC equipment, skylights, and cooling towers.
Elimination of Ponding Water - In reroofing applications, ponding water may be eliminated by adding an increased thickness of polyurethane foam in low areas. Building up the low areas and sloping the roof so that it drains properly will eliminate ponding water.
Lightweight - ASPF weighs between 2-3 pounds per cubic foot. One inch of polyurethane foam insulation plus 30 mils of an elastomeric coating weighs approximately 60 pounds per 100 sq. ft., as compared to approximately 600 pounds per 100 sq. ft. for a typical conventional four-ply built-up roofing system.
Versatility - It can be used on both new and replacement roofs, whether flat, pitched, saw-toothed, domed or having unusual slopes or configurations. It is also ideal for the spray application to tanks, freezers, coolers, piping, ductwork and various aerospace projects.
Flexibility - It has the ability to withstand a structure's normal expansion and contraction without affecting the ability to keep the structure protected from the outside elements.
EVALUATION - A PERSONAL TESTIMONY
The contrast to a neighbors mobile home home which does not have a polyurethane roof is dramatic. We recently visited a friend who also has a single-wide mobile home facing toward the south just like ours. It was about 11 AM. When we went inside it was very hot and uncomfortable there. Our friend turned on his evaporative cooler soon after we arrived, but it didn't help much to cool things off inside. When we got back to our place at about noon, our mobile home was nice and cool inside, and we did not have to turn on our evaporative cooler until about 2 PM.
WAS ADDITIONAL INSULATION NEEDED?
Since the greatest proportion of heat loss in the winter and heat penetration in the summer is through the roof, it would seem that putting your insulation dollars into the roof would be the highest priority if your budget is limited. For summer, our mobile home was very comfortable indeed with just the polyurethane foam coating on the roof.
We found during the Winter months, however, that additional insulation was needed for optimum efficiency of our heating system. We installed two inch Expanded Polystyrene (EPS) sheets on the exterior walls of the trailer, then applied a coating of stucco. Heating costs went down. We have a very comfortable mobile home!
Solar Haven Main Page - Stuccoing Our Mobile Home
©2002-2014 by Jim Phypers