Question: We own an apartment building in North Hollywood that has a totally flat roof. Every few years we install a new composition roof and it starts to leak again. We believe that the solution lies in providing a pitched roof. Would you know of any companies that could install a totally new inclined roof. We sure could use your help. — Karl
Answer: Karl, I spoke with two licensed general contractors with decades of experience each and their consensus was that putting a sloped roof on top of your building would be many, many times more expensive than paying top dollar to get a superior job done to your existing roof.
The advances in roofing technology are amazing. Have you seen mention of “green roofs” lately? These are flat roofs covered with a thick rubber membrane that allows for turf to be planted on top. This is done for insulation value, to cool off the building in hot climates and to provide oxygen to the air. You could take advantage of these new materials to get a better roof than composition material could provide.
I asked Chatsworth general contractor Alon Toker of Mega Builders what he thought about creating a sloped roof over a flat roof, and here’s what he said:
The reframing option would require expensive plans and engineering, and then the framing and roofing. But compared with a quality reroofing of your current roof, the reframing option would be several times more costly. Continued . . .
The problem with flat roofs is water runoff can be poor. Also, the sun (the real enemy of roofs) hits the roof at close to a true angle, and so it is most destructive.
The bottom line is that flat roofs are more susceptible to leaks, so shortcomings in materials, installation or both have more consequences.
If a reroof is done to the highest quality possible, a building owner should get more than 10 years from a flat roof (12 to 15 is a reasonable expectancy). Not many roofs (flat or pitched), however, are done to the highest standards, unfortunately, and given its greater susceptibility, the flat roof will show its faults sooner.
The remedy is not reframing of the roof (an investment never to be recaptured) but educating yourself about flat roofs and limiting the bidding to top roofers. You want the best company using the best materials available. In challenging home-improvement situations, it always does seem to get around to this, doesn’t it? In the long run, though, you will save money and hassle with a superior flat roof, and I think that is your goal.