What silicone does better
Silicone coatings resist breakdown from standing water and from intense UV better than acrylics. On Albuquerque roofs with shallow spots that pond for a day or two after monsoon storms, silicone tends to keep its film where acrylic would soften.
Silicone at a glance
| Silicone | Acrylic elastomeric | |
|---|---|---|
| Ponding water | Handles it well | Wears faster where water sits |
| UV resistance | Excellent | Very good |
| Cost | Higher | Lower |
| Picks up dirt | More — can look gray sooner | Less |
| Recoating later | Must use silicone | Many coatings bond |
The trade-offs
- Future recoats need silicone. Very little else sticks to it, so you're choosing silicone for the long run.
- It collects dust. In a windy, dusty city a silicone roof can look duller sooner, which slightly reduces how much heat it reflects.
- It's slick when wet. Something to know if you go up to clean canales.
- Prep has to be clean and dry. Silicone is less forgiving of a poorly washed roof.
Fix the water first when you can
Silicone tolerates ponding, but it doesn't fix it. Water sitting on a roof finds any small defect, and the weight stresses the structure. Where practical we build up low spots with foam or adjust drainage at the canales before coating. See flat roof leak repair and parapets and canales.
Is silicone right for your roof?
If your roof drains within a day of rain, acrylic is usually the better value. If water stands for longer in several places, or you want the longest-lasting coat and accept the higher cost, silicone deserves a look. We'll tell you which one we'd put on our own roof — see silicone vs acrylic.
Call (505) 886-8732 and we'll price both so you can compare.
Common questions
Can silicone go over my existing acrylic coating?
Often yes, after cleaning and the right primer. Going the other way — acrylic over silicone — usually doesn't work.
Does silicone cost much more?
It's typically somewhat more per square foot than acrylic. On roofs that pond, the longer life can make up the difference.
Is silicone white?
It's usually available in white and light colors.