It doesn’t happen often in Tucson, AZ, but every year, there seems to be a handful of days between November and March when the temperature drops below 32 degrees Fahrenheit at night and the temperature stays below 60 degrees in the daytime. This tends to bring up the question: WHAT IS THE MINIMUM TEMPERATURE A ROOF COATING CAN BE APPLIED AT? The answer may seem simple—55 degrees Fahrenheit, as it states on the label. However, there’s more to the answer than that. You can use the following information to explain to your customers and clients why you will or won’t apply roof coatings in cold weather.
Factors that Affect Roof Coating Application
The question should not be what minimum temperature can the coatings be applied at, but rather what temperature will the coatings fully cure at before the sun sets and frost begins to form? If the roofing substrate is bone dry with no moisture and is not going to experience moisture for days, then it would be fine to apply our elastomeric roof coatings at temperatures between 40 and 50 degrees Fahrenheit. After all, we build these products to perform in Arizona’s extreme variations in weather. However, there are certain factors to keep in mind.
As long as the coating has time to cure with no moisture affecting it, then the temperature doesn’t matter (as long as it’s above 32 degrees Fahrenheit). That said, these products are water-based. Thus, if the product freezes at any point during the curing process, the performance of the coating will be compromised.
The major issue faced is the curing time during these winter months. Even in our dry climate, there is moisture in the air. At low temperatures, this moisture tends to gather and remain on roofs and vehicles longer into the morning than on warmer days. If moisture from the night before is not dried before the coating is applied or if that moisture settles on a roof coating that is not fully cured, adhesion issues may occur.
On a 55-degree day with the sun shining, the coating will theoretically cure if given proper dry time. The issues come up when there are parapet walls, solar panels, A/C units, valleys, or trees that block the sun from some areas of the roof. Even in 55-degree weather, if a coating doesn’t see any sunlight, the risk of it not curing properly is present. Furthermore, if a roof coating is applied when it is 55 degrees Fahrenheit on a cold, sunny day at 2pm and the temperature begins to drop soon after, that coating may not cure properly.
The issue to evaluate is whether the coating will be able to cure before the frost settles at night. The answer is not always black and white unless you’re not coating between November and March every year. And who has time for that?
About Tucson Rubberized Coatings
We hope that this information will assist you in making the decision of when or when not to coat during the winter months. We’ve been around for decades and have seen quite a bit, so we know what hurdles are faced. This is why we do provide a product that will set and dry quicker to give you the best opportunities for success.
The answer to our initial question is 55 degrees Fahrenheit because that is typically a safe minimum temperature that will allow coatings to cure properly. However, be sure to always use your best judgement, as every roof is different.
Do you have other questions about our roof coatings and how to apply them? Contact Tucson Rubberized Coatings at any time with any questions you may have.