What to Do if Your Roof is Leaking

Office interior with a leaking roof.

Know the Steps to Take for a Leaky Roof

To own a commercial structure is an awesome feeling of success and prestige. Or is it? While a commercial structure has its impression of being successful, it can also lead to worries, like a commercial roof leak.

Yes, as the size of your building gets bigger, the problems can get bigger too. So what happens if you don’t fix a roof leak?

A lot! A leaking roof for a home is bad enough, but when you ignore it, it simply exacerbates it for a commercial building because there is more to be affected and damaged. What damage can a leaking roof cause? Here are just a few of the dangers you could be faced with: 


Because a commercial building is larger than a residence, there is more space, and the more space, the less likely you are to find water dripping in little by little. So that small drip is left to be, and before long, there is a dark, mildewed, molded, wet corner in your building. Not only is it discolored on the ceiling and walls, and even the floor, that mold is sucking into your HVAC system and spreading through your building like a fire. 


That first issue leads to health concerns and adverse effects that your customers and employees could be suffering. Mildew and mold are major allergens for everyone, even healthy people. And anyone that suffers a respiratory illness or is immune-compromised is even more susceptible. That’s not to mention the puddle of water that could lead somebody to slip and fall. That commercial roof leak could cost you in employee time off. 


Water is a natural resource that we need to appreciate and conserve. However, it is an evil to a structure. Besides causing mildew and mold discoloration that will need repainting, a commercial roof leak will also weaken a structure’s framework. The ceiling starts to sag, the walls can’t hold up and begin to buckle and sag, and before you know it, you have a collapsed building. Or a partially collapsed one, anyway.


Any building will use a lot of wood in the construction process. The bigger the building, the more wood, like the ceiling joists and rafters. As we said above, water is not a friend of wood, yet wood still absorbs the moisture, a love lost but not yet recognized. As the moisture content’s stability is disrupted from a commercial roof leak, the wood begins to expand and contract, and that makes the integrity of the structure vulnerable. The wood will eventually buckle, rot, and collapse, and the only thing to do is replace the wood.


An aspect that will affect residential or commercial structures alike is the damage to electricity that can happen with a roof leak. Dry housing is preferable for electrical wiring and even when it has a moisture-proof coating, it can become compromised, and areas that aren’t protected can be shorted out. 

Is a leaking roof an emergency?

Yes –  based on the information we just provided, if you discover a leak in your commercial structure, you need immediate roof leak detection and repair. If the commercial roof leak is disrupting your business here and now, then of course you’d get it repaired right away, right? By putting it off though, re-read the paragraph above and let that convince you that NOW is the time to fix that commercial roof leak. 

How do you temporarily fix a leaky roof?

If you have a major commercial roof leak, you’ll need a professional roof leak repair company to fix it right, which may mean an all-new roof. However, if you have just a small leak and a small budget, you can use the following steps to stop the leak temporarily and get you a professional roof leak repair estimate later: 

  • Locate the Leak

Look inside the building where the leak is, although where it is pooled up doesn’t mean that’s where it’s coming from… but it’s a start. Measure the area suspected of leaking from the nearest wall or window. 

  • Up on the Roof

From the measurements you have from inside, search for the leak on the rooftop. Look for roof membrane damage around the flashing and vents.  

  • Remove the Debris

Remove any debris and other foreign matter that has collected on the roof. You may find what caused the leak. 

  • Dry the Area

A flat roof collects water, so you want to get the damaged area as dry as possible before you begin repairing your commercial roof leak. 

  • Identify the Damage

Look for blisters, cracks, and damage to the roof.

  • Cut the Damaged Area

If there is a blister, carefully cut out the blistered, damaged membrane and remove the moisture (though remember, it needs to be thoroughly dry). 

  • Apply the Roofing Cement

Peel back the membrane layers that you just cut open and apply a generous coating of roofing cement to the leaking areas and surrounding spaces.  This will plug the commercial roof leak and provide adhesion for the flaps to stick down.  Now press hard so they can reseal. 

  • Nail it All Down

With all the flaps you created down in place with the adhesive, nail them down to the roof to secure them, being careful not to nail any wires.

Commercial roof covered in puddles.

Is a leaking roof covered by insurance?

Just like homeowner’s insurance, business insurance would cover water damage of a commercial leaking roof if it were caused by a covered event. A covered event will be spelled out in your policy, but typical coverage includes hailstones, high winds, and the like. 

Even with a temporary commercial roof leak, you should have a professional roofing contractor inspect the entire roof and give you an estimate and advice on making a permanent roof leak repair or replacement. Need help now? Call Great Lakes Commercial Roofing today at 412-256-8050.