Can You Roof Over Your Commercial Building’s Existing Roof?

When you're dealing with a commercial roof that's showing signs of age, you may be wondering if you need to have the building's roof completely replaced or if you can simply have a new roof installed on top of the existing one. In order for your commercial roofing contractor to install the new roofing material on top of the existing roof, the existing roof must meet certain conditions. If you're trying to decide whether or not your commercial roof is a candidate, these are some of the things that you'll need to assess with your roofing contractor.

How Many Roofing Layers Are Already There?

The first thing that you must consider is how many roofing layers there currently are on your building. You can't apply the new roof over the existing one if there's already two roofing layers in place. You'll need to talk with your roofing contractor to ensure that there's only a single layer of roofing on the building before you consider this type of restoration. He or she can inspect the roof and let you know how many layers of roofing material are in place on your roof.

Are There Any Loose Fasteners?

Another important thing your roofing contractor needs to consider before you decide if you can apply your new roof over the existing one is the condition of the roof fasteners. In most cases, you'll need those fasteners to all be secure and in good shape before you can apply another roofing layer over the top of them. If only a couple of the fasteners are coming loose, your roofing contractor may be able to work with that as well, but if there are many fasteners backing out of the roof, you'll need to talk about more extensive repairs.

Is There Any Pooling Water?

Pooling water on a commercial flat roof is a recipe for disaster. Over time, this water will seep through the roofing material, causing water damage to the insulation and the subroofing beneath. Your roofing contractor will need to explore the roof either after a rainstorm or after treating it with a hose to see if you have any areas where water is pooling. This indicates either poor drainage or damage to the roofing panels, either of which will need to be addressed.

In the case of poor drainage, if there's no damage beneath the roofing surface, you can have a new roof installed over the top with an appropriate slope to eliminate the drainage issue. In the case of damage, you may need to have the existing roof replaced instead.

What Is The Condition Of The Existing Metal Roofing Surface?

You can't apply a new roof over the top of an existing metal roofing surface if that metal is corroded or heavily damaged. Your roofing contractor will look for any signs of rust or corrosion before deciding if you can apply a new roof over the existing one.

Remember that, left unaddressed, that rust and corrosion will progress, leading to deterioration beneath the new roofing surface. This will weaken the integrity of your new roofing material as well, which is why you shouldn't apply new roofing over damaged metal roofing panels.

Applying a new roof over the existing one on your commercial building can be a cost-effective and time-saving way to address an aging roof. However, you need to be sure that you're approaching the process correctly. Roofing over an existing roofing layer can be damaging if it's not done properly. That's why it's important to consider these points and work closely with a commercial roofing contractor to assess your building's existing roof before you decide how to address the problem.

Contact a company like Tectum Roofing to learn more.


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