Roof Coating During Monsoons

Roofing contractors in Tucson are often asked if we can do roof coating during monsoons. The answer is yes. There are a few things to keep in mind when coating roofs during the rainy season in Southern Arizona. If certain precautions are followed then a roof can be properly coated and would be no different than if coated during the drier weather seasons.

Moisture Causes Problems For Elastomeric Coatings

When monsoons hit in Southern Arizona it rains for short bursts of time and then the relatively dry air soaks up the moisture. If you notice, just an hour after a rain the roads are dry once again. The heat and sun cause the rain water to dry road surfaces and also roof surfaces. Humidity in the air is not a problem for elastomeric roof coatings. Such coatings are water based and the humidity has no effect on them. However, moisture on the roof surface can cause problems. Roofs must be moisture free when applying roof coatings. If the roof is wet when the coating is applied, the top of the coating will dry and trap the moisture underneath. When the roof heats up the moisture will try to escape upwards and cause little blisters in the roof coating. These blisters can later dry, crack and become areas for potential leaks. Humidity is fine, moisture is not.

Before Applying Roof Coating Make Sure The Surface Is Dry

Roofs heat up quickly in the summer. In fact, it can be 10 or 20 or even more degrees hotter on a roof than on the ground below. Because of this, roofs dry rather quickly after the rains. As noted above, the heat causes the water to evaporate and the roof surface to dry. The best roofing companies in Tucson would never coat the roof when the surface is still wet. Your roofing company should check the roof and confirm the roof is ready for the coating to be applied. Of note, the companies that produce elastomeric roof coatings may say that the roof needs to dry 24 hours or so before coating. Remember that they write their instructions to prevent lawsuits and for the average homeowner in mind. They will always lean to the extremes when writing their instructions. Their warranty will not be void as long as the roof surface is dry before applying the roof coating.

Apply Roof Coating At Least 2-4 Hours Before It Rains

Many, NOT ALL, elastomeric roof coatings can be applied 2-4 hours before the monsoon rains in Tucson. Monsoons are caused by the extreme heat in the mornings that draw in the moisture in the afternoons. Most roof coatings will dry within an hour or two after being applied when put down during 90-95+ degrees. Desert Sky Roofing uses Tucson Rubberized 7000 roof coating which usually dries within 1-2 hours after application. Roof coatings do not completely cure in that time, but they will dry to the point where they can be walked on without sticking to shoes. One to two hours will make the roof coating plenty dry to repel water if it rains the same day it was applied. Most professional roofers will watch the weather religiously to make sure they have enough time to apply roof coating during monsoons.

What Happens When Coatings Are Applied On Wet Surfaces

If roof coatings are applied when the surface is wet, it is not the end of the world. At first the coating will look great. Over time the coating will start to blister. Blisters are created when the moisture that got trapped under the coating tries to escape pushing the coating upward. These blisters will not hurt the roof in the near term but they can dry out and eventually crack open. Open blisters can be possible leaks in the roof. Blisters can be removed by scraping them and applying roof coating, patches, or mastic over the top of them. Your roof may not look as smooth after repairs are made but it will be serviceable.

What Happens If It Rains Immediately After Coating The Roof

As stated above, a couple hours should pass before it rains on a freshly coated roof. If perhaps it rains while the coating is still wet some of the coating could wash off and flow out of the scuppers. This could cause pavers, concrete, or whatever is below the runoff to have a white tinge. To prevent damage, we recommend not letting the surface dry before washing it off with a garden hose or pressure washer. Elastomeric roof coatings are water based and can be washed off easily. The will need to be scraped or brushed off if the white water is left to dry. To our knowledge, the coatings are not harmful to the environment.

Hire A Professional Roof Coating Contractor

The best way to get your roof coated properly during monsoons is to hire a professional, licensed, roof coating contractor who can explain their processes and how they do roof coating during monsoons. This article provides some information that can help you have a proper discussion with your roofing company about the rains. Ask the roofing company about their warranties and if it includes blisters if they coat the roof prematurely. Most professional roofing professionals will know when they can coat a roof and when they cannot and will back their work with a solid warranty. They work with the roof coating material on a daily basis and know how long it takes to dry and when they should or shouldn’t press forward. If in doubt, ask your roofing contractor to reschedule coating your roof if you don’t feel you can trust them. Keep in mind, that during monsoon season roof coating companies are usually busy helping many clients so you might go back farther in the schedule, but at least you will have peace of mind about your roof. If you are looking for a solid roof coating contractor who will stand by its processes and warranties, call Desert Sky Roofing. We know when to coat a roof and when not to and will “roof it right the first time.”