When it comes time to replace or renew the roof of their home, Eichler owners have a more difficult time making a decision on how to proceed than the average homeowner, who typically settles on shingles, shingles or shingles (albeit of different types). The flat or minimally-sloped roofs that crown nearly every Eichler ever built—even the 60's era center gable models are more flat than not—lend themselves to range of roofing materials. From the old standby, tar-and-gravel, to modified bitumen three-ply, polyurethane foam, or single-ply systems (such as the Duro-Last product), the homeowner must sort through a range of conflicting opinions and choices.
Determining the answers to a few basic questions can help guide the homeowner to a roofing solution that is right for them. However, be forewarned, there is no single "right" answer for everyone, as these days a quality roof can be had in a variety of forms.
Does your current roof need to be removed?
If your roof had a poor quality installation in the past, or wasn't properly maintained and has deteriorated past the point of being repairable, then it may need to be completely removed before the new roof is applied. To apply a new tar-and-gravel roof or a modified bitumen three-ply, tear off of the existing roof is generally required, so removal of your old roof would have to be done anyway. But polyurethane foam and most single-ply systems can often be applied over the existing roof, even if it's leaking, avoiding tear off costs.
How important is conserving energy?
Homeowners who have gone from the original Eichler roof, with its almost useless half-inch of fiberglass insulation, to a modern insulated roof are invariably amazed at the dramatic difference it makes in both blocking the summer heat and retaining precious heat through the winter. Rigid foam insulation can be added beneath any of the roofing systems listed above, and of course spray-on polyurethane foam roofs are by their very nature highly insulating. While changing to a well-insulated roof will surely reduce your heating bill to some degree every winter, if your current roof is in good shape it probably does not make economic sense to put out for a new roof just to cut down on your gas cost over the winter: it would take several decades to recoup that investment. The real benefit will be in increased comfort during the summer months.
Is the original Eichler roof appearance important to you?
There are those who consider white or shiny roofs an eyesore, and depending on how your house is oriented to the street, and towards its neighbors, a brilliant white roof can be a problem in neighborly relations. This is not a trivial concern, but at the same time, light-colored or reflective roofs can significantly reduce heat gain in the summer, making your non-air-conditioned Eichler much more comfortable. Alternatively, you can try to have it both ways by having rigid foam insulation installed under a tar-and-gravel application for that dark, authentic look.
Is price a primary concern?
Everyone has to live within their means, except Larry Ellison, but then that poor guy doesn't live in an Eichler. If price is the most important consideration, one may decide to go with tar-and-gravel on that basis alone, but keep in mind the projected lifespan of that roof before re-roofing is required, and the cost of the re-roof. Modified bitumen, foam, and single-plys like the Duro-Last system can offer up to 20-year warranties with varying degrees of maintenance.
Finally, don't neglect the importance of choosing a qualified, reliable roofer for this job. The best roofing materials can be worthless unless they are properly installed. Ask neighbors and friends how they handled re-roofing and the choices they made: first-hand experiences from a variety of sources can be the most valuable information of all.