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Questions & Answers

  • I am unclear about the coverage rates for GacoRoof. The package and the brochure seem to have different rates. Why is this?

    The confusion between the brochure and package is this: because TWO coats are required, the coverage for the COMPLETED project is 1 gallon per 50 square feet. (You can use this rate to figure out how many gallons you need to purchase). The APPLICATION rate (the amount used to gauge the proper thickness when rolling the silicone coating onto your roof ), is 1 gallon per 100 square feet.

  • So, how much Acrylic roof coating do I need for the same job?

    Acrylics typically require more than DOUBLE the amount of GacoRoof coating for the same roof project. For most acrylics, you need to apply one coat of sealant and/or primer, PLUS a base coat, PLUS one or two additional top coats at a rate of 1 gallon per 100 square feet. You’ll need 1 gallon of primer and 2-4 gallons of acrylic roof coating for every 100 feet. When you include accessory products, such as patch compound, fabric and sealer, the cost of an acrylic coating really adds up. And don’t forget that the typical acrylic roof only lasts about 3-5 years before a recoat is required!

  • Are you sure my roof does not need a primer coat? Do I need to prime metal flashing or other metal surfaces?

    Metal flashing should either be primed with an exterior metal primer, or lightly sanded. Most other roof surfaces do not require a primer before applying GacoRoof. See the list of acceptable substrates below.

  • OK, so how does GacoRoof compare to acrylic roof coatings?
    1. GacoRoof has a 50-year limited warranty. GacoRoof will last as long as the substrate it is applied to. Acrylics, if they have a warranty at all, warranty only 3-5 years. One acrylic offers an 8-year warranty BUT you have to recoat every 3 years.
    2. GacoRoof can withstand PERMANENT ponding water. There are no acrylics that will stand up to the stress of permanent ponding water without bubbling or adhesive failure.
    3. GacoRoof can be applied in a wide temperature range (32-120 degrees F). Acrylics cannot be applied at temperatures below 55 degrees or above 90 degrees.
    4. All acrylics require a primer coat. GacoRoof does not require any primer, sealer or patch compound.
    5. GacoRoof does not require a recoat. Silicone is inert, and does not degrade or wear away. Acrylics require a recoat every 3-5 years.
  • What substrates does GacoRoof adhere to?

    GacoRoof adheres to a multitude of roof types. Suitable substrates include silicone, aged asphalt (not for use on 3-tab asphalt or architectural shingles), aged EPDM and TPO/CPA (may require GacoFlex E5320), built-up, cap sheet, composite, concrete, fiberglass, metal, modified bitumen, torchdown and sprayed polyurethane foam. GacoRoof is perfect for Residential and Commercial buildings, as well as flat and low-pitched roofs, mobile homes, RV’s and campers.

  • What about EPDM & TPO Roofs?

    GacoRoof may be applied to Aged EPDM and TPO roofs but may require the use of GacoFlex E5320 2-Part Epoxy Primer/Filler. To verify adhesion, use the GacoRoof AdhesionTestKit, which provides results in just 24 hours. If the test reflects poor adhesion, prime all surfaces with GacoFlex E5320 according to label directions. Call toll-free (866) 422-6489 for more information and specific recommendations.

  • Does GacoRoof come in other colors?

    GacoRoof is available in White, Gray, Green, Light Tan, Rustic, Medium Blue, Black, Brown and Red. GacoRoof White may be tinted Gray using GacoRoof Colorant, which can then be applied as the base or top coat.

  • Can GacoRoof be applied with a sprayer?

    GacoRoof should not be sprayed because it is too thick for spray equipment. If GacoRoof is thinned with mineral spirits, it no longer meets the regulations for minimum V.O.C.’s (volatile organic compounds).

  • What is skinning? What happens if I don't use the entire pail right away and a skin forms?

    Skinning is when the topmost layer of coating begins to cure in the pail. Silicone is moisture-cured, so high heat and humidity will cause the product to skin. If surface skins, remove skinned material from container. To minimize skinning over several days, pour a thin layer of 100% mineral spirits on top of product until it is completely covered and do not move pail until ready to reuse. When ready, stir thoroughly with a power mixer. Keep container tightly closed between applications to minimize surface skinning.

  • Does GacoRoof have a UL (Underwriters Laboratory) Approval Rating?

    Yes, GacoRoof is UL rated when applied to a non-combustible surface.

  • Is there a mildicide in GacoRoof? Does GacoRoof mold or mildew?

    There is no mildicide in GacoRoof, because mildew does not grow on the surface of GacoRoof. Unlike acrylic coatings, GacoRoof is inert and does not provide a food source for mildew or mold.

  • Can my GacoRoof be pressure washed?

    You can pressure wash GacoRoof at a low pressure (below 2,500 psi).

  • I know that GacoRoof is perfect for flat roofs. Can I use GacoRoof on my peaked roof?

    GacoRoof does cover peaked roofs as well as flat roofs. Use extreme caution when on a pitched roof. Follow all safety guidelines to avoid injury. The reason that we emphasize our flat roof coverage is that flat roofs are notorious for having puddles and drainage problems and acrylics degrade rapidly under those conditions. Up until now, the only choice for building owners with flat roofs was smelly hot asphalt or recoating every 3 years with an acrylic.

  • Since both coats are white, how can I see where to apply the second coat?

    Snap chalk lines as needed to see where to apply the second coat. Alternatively, GacoRoof Colorant can be used to tint one coat (base or top) gray, providing greater color contrast between the two coats.

  • Can GacoRoof be applied to roof decks or walkways?

    Silicone can be slick, especially when the surface is wet, so GacoRoof should not be used for areas with foot traffic. GacoDeck Kit is a better choice for roof decks.