On The Sky High

When installing a new roof, many homeowners will opt to install the new one over the existing one. Some roofers even promote this option when the existing roof is in decent enough shape. If you’re considering having a new roof installed and are wondering whether to tear off the current one and start from scratch or install over the existing ones, consider the following pro (yes, there’s only one) and cons.

The Pro

The only real advantage to installing the new roof over the existing one is saving money. Part of the cost of a new roof is removing and disposing of the old one. Installing over eliminates this part of the project thereby reducing labor costs associated with the roof installation. Having two layers of shingles does not make the roof more effective or weather resistant.

The Cons

The biggest downside to installing over an existing roof is that you don’t discover any potential problems beneath the existing roofs. Often when the old roof is torn off, there’s rot in the roof deck or other structural issues. Undiscovered problems have a tendency to get worse over time.

Another downside is that any future repairs are going to be more expensive. If there’s a roof leak for instance, roofers have to go through two layers of shingles to find and fix the problem which adds to the labor costs.

Another problem with installing over an existing roof is that most roofing shingle manufacturer’s won’t honor their warranty if they’re installed on top of an existing roof since they’re designed to be installed right onto the roof deck.

A problem that probably won’t apply to newer homes but might be an issue for older homes is weight. The weight of two layers can put a strain on the home’s roof structure and lead to some areas sagging.

Finally, it’s important to keep in mind that the one pro (savings) are offset by still other cons. The savings you get from installing over an existing roof are minimal and temporary. For one, installing over an existing roof involves some prep work that wouldn’t need to occur if the old roof is torn off. The savings are temporary because in another 15 or so years, you’re going to need a roof replacement again and now two layers will need to be torn off which means twice as much labor and twice as much waste.

In conclusion

If you need a new roof, don’t cut corners. If your Spokane roofing company even suggests installing over your existing roof, find a new one.

Home improvement news brought to you by bartonroof.com