2 FM quick reads on reroofing
1. When is Reroofing the Best Option?
If you have walked your roof and determined that the roof is still in fairly good condition, you may want to consider coating the existing roof to avoid the cost of reroofing for another five to 10 years, depending on the coating and the condition of the original roof. A coating usually has a five-year life over an aged roof system. However, before doing so, a moisture survey is a necessary step.
Recoating has the advantage of being least costly of the options for reroofing and, because they are generally light-colored, coatings can reduce air conditioning costs. However, a wet roof should never be recoated. So before you make the decision to coat the roof, get a moisture survey done to determine the percentage of wet roofing. If the roof is more than 25 percent wet, don't waste your money coating it. Keep reading for some other possible solutions.
If your roof has many of the above problems and has been leaking for a while, you can safely assume you need a new roof.
Three steps can help you decide whether reroofing is a better investment than repairing the existing roof.
- Figure out the amount of money you have been spending on repairs each year over the last few years. Divide the total by the number of years you have included in your analysis.
- Figure out the cost to reroof and divide by the number of years the roof is expected to last. A good suggestion is 15 because that is an average warranty length.
- If No. 1 is more than No. 2, it makes economic sense to reroof because it is costing you more per year to keep the old roof in place than the yearly cost of a new roof. It is time to reroof.
Big Top: Reroofing California's State Capitol
Every single step, it seems, presented a challenge when it came to reroofing the California State Capitol building in Sacramento — scheduling, security, and maybe the most maddening challenge of all, surprises. Throw in the chaos created by the building's 3,000 occupants — including a state legislature and its committees in and out of meetings — as well as 750,000 visitors annually, and the entire process might even seem overwhelming.
For all its challenges and surprises, one main goal of the reroofing project on the California state capitol building focused on a problem every maintenance and engineering manager knows all too well — leaks.
"It was leaking profusely," says John Manning, the building's chief engineer, referring to the 98,000-square-foot surface that included several types of roofing systems and nearly 30 different sections — some sloped, others flat.
"There are actually two buildings that comprise the current state capitol," Manning says. "The first completed construction in 1869. Then in the late 1940s, a second building was built directly next to it, so it becomes one building. That finished construction in 1951."
"The roof had been on the capitol for more than 20 years, and there were leakage problems, and it was at the end of its life," says Marilyn Nelson, project manager with the state's department of general services. "When we replaced it, there were several roofing systems down below it, and we had some hazmat issues. We had to do all the demolition at night, and we reroofed it during the day. Because it is such a large roof, we had to do it in sections and phases."
The new roof is a PVC system with 10-foot-wide panels.
"We chose it because it was long-lasting and durable," Nelson says. "As you can imagine, you don't want to reroof this capitol very often. It also had a decent solar-reflective index. And it has fewer seams because of the 10-foot-wide panels."