Many homeowners around the Tucson and Green Valley areas are wondering whether it is worth paying the extra money for 100% silicone roof coating. Many marketing companies are attempting to get homeowners to move away from the typical elastomeric acrylic roof coatings and to use silicone because it lasts longer. Some roof coating contractors are also pushing this material. There may be some benefits to using silicone but there are also some risks to applying these coatings to your roof. Here are some pros and cons that should help you determine if it is worth applying a 100% silicone coating to your roof.
Elastomeric vs. Silicone Roof Coating at a Glance
Every figure below reflects the products DSR installs on Tucson flat roofs, so the numbers here and the numbers on our service pages agree.
| Acrylic elastomeric | 100% silicone | |
|---|---|---|
| DSR product | TRC-7000, TRC-XFusion, TRC-10000 | TRC-990 |
| Service life, two coats | 5 to 7 years (TRC-7000), 8 to 10 years (TRC-10000) | 20+ years on a genuine candidate |
| Material cost | Baseline | Roughly 3x per gallon |
| UV reflectance | 87% (TRC-7000), 91% (TRC-10000) | High when new, falls as it soils |
| Look over time | Stays white, washes clean | Attracts dust, goes dingy, will not wash clean |
| Repairs | Patch and recoat with acrylic | Silicone only, permanently |
| Best fit | Most Tucson flat roofs, BUR and foam | TPO or EPDM, chronic ponding, few penetrations |
Neutral: How Long Will You Be In Your Home?
If you are expecting to move within the next few years it may not be worth buying silicone. Two coats of acrylic elastomeric roof coating usually lasts 5 to 7 years before a recoating is needed. Silicone is more expensive so it may not be worth using if you are going to sell your home in the next few years. If you are going to remain in your home for a longer period of time silicone coating may be an option for your roof.
Con: 100% Silicone Roof Coating Costs 2-3 Times More Than Elastomeric Coating
The materials costs for one coat of premium acrylic elastomeric coating on 1000 square feet of surface area costs around $250-350. The same amount of silicone coating will cost between $700-900 and this doesn’t take into consideration the epoxy primer that many silicone roof coatings require to prep the roof which is an added cost. Silicone coating is going to cost between 100-150% more in material expenses. Also, roof companies may charge more for their labor to apply 100% silicone coatings because of the difficulty making sure the coating is properly laid down. The cost of silicone may not be in the budget for many homeowners.
Neutral: 100% Silicone Coatings Should Be Applied By Professionals
Do you trust your roof coating contractor? When you are considering the pros and cons of using 100% silicone roof coating, know that it should be applied carefully. The real challenge with silicone is that nothing sticks to it when it dries. If the coating is not applied almost perfectly it is not worth doing. Silicone is not very forgiving after it dries. Nothing sticks to the coating and most companies producing these materials will tell you where there are problems, they need to be cut out and more silicone poured into the cut out section. However, they will also tell you that the weak point will be where the edges were cut out. Silicone is a challenge to deal with after it is dry. If you don’t have a near perfect application it will be a significant challenge repairing areas that were not applied properly. Worst case scenario is that your roof will need to be replaced if the coating has significant problems after application. We all know roof replacements are very expensive! Therefore, make sure the roofing coating company you choose is trustworthy, will not skip steps – especially the cleaning and preparation step, and will put down the correct amount of silicone roofing material, at the proper temperatures for application. Remember, some of the shady companies will skimp on materials so they can save money. These companies will be tempted to skimp when they are paying $250-400 a five gallon bucket for silicone! They will also try to coat the roofs when they are not completely dry or completely clean. Be sure you can trust the company you hire if you are going to use 100% silicone.
Con: 100% Silicone Roof Coatings Brown Over Time
When 100% silicone roof coatings are applied they go on bright white. However, over time they turn dingy brown due to dirt and grime sticking on the coating. Pressure washing and brushing off the dirt is difficult, so once they brown they are going to remain brown. Unfortunately, this doesn’t provide the best reflective value for energy savings. If applied correctly, the coatings will last longer but browning should be considered.
Pro: 100% Silicone Coatings Last Longer
100% silicone coatings last considerably longer than typical acrylic elastomeric cool coatings. Silicone is strong, pliable, and durable. As long as the surface is properly cleaned and dried and the coating is professionally put down, the coating will last. If browning is not a concern, nor the money for the coating, and the home is a proper fit for silicone coatings maybe using them would be best. However, one thing to keep in mind is that maintenance is required on all coated style roofs. Be sure to check your roof every 6-12 months even if it was coated with silicone.
Which Roofs Are Genuinely Good Silicone Candidates
Silicone is not a better coating in general. It is a better coating in specific conditions, and those conditions are narrow enough that most Tucson homes do not meet them. We recommend TRC-990 when a roof checks all of these:
- The substrate is a TPO or EPDM membrane rather than a hot-mopped built-up roof
- The roof ponds chronically, which is where silicone’s water tolerance genuinely outperforms acrylic
- There are few penetrations, since every scupper, vent, and HVAC curb is a place a silicone application can go wrong permanently
- The underlayment below is solid and the roof has no history of repeated repairs
- You are staying in the home long enough for a 20-year coating to pay back a 3x material cost
Miss any of those and acrylic elastomeric is the better value, which is why the overwhelming majority of the flat roofs we coat in Tucson get TRC-7000 or TRC-10000.
These are pros and cons of using 100% silicone roof coating on your roof. Hopefully this will help you when you talk to your roof coating contractor about using silicone roof coating. At DSR Roofing we are particular on which roofs we would apply silicone roof coatings. Not all roofs are good candidates for silicone. If you are not familiar with these coatings or have not had much experience applying roof coatings, we recommend you allow a professional to apply the coating. We love do-it-yourselfers and even have a “do-it-yourself plan” created specifically to help such homeowners, but we highly recommend a properly licensed company with experience laying down the silicone materials do the work. Give us a call if you have any questions and we would love to provide a free inspection for your roof and let you know whether your roof is a good candidate for silicone if that is what you want to do. Call us today at 520-444-5218 or fill out the form on our website if you are looking for a roof coating contractor in Tucson, Green Valley, Oro Valley, Vail, Marana, Catalina Foothills, Sahuarita, or anywhere in the general Tucson area.
