Home » How to Guides » GacoPro 100% Silicone Roof Coating – How To Guide

GacoPro 100% Silicone Roof Coating – How To Guide

We no longer stock this product; see our wide range of Roof Paints to protect and decorate your roof. From waterproof roof coating products for both pitched and flat roofs, to paints that provide joint reinforcement and protection for felt, metal, concrete, timber and many more surfaces.

It is extremely important to get the roof clean and dry. First remove heavy deposits of dirt, leaves and other debris from the roof, then inspect the entire roof surface and flashings for any open seams, tears, cuts, etc. Repair these flaws so water is not blown in under membrane during the cleaning process. Pressure wash roof with water and allow to dry completely.

Flat Roof Preparation

For general cleaning, apply GacoFlex GacoWash concentrated cleaner according to label instructions. On all single-ply membrane roofs, after application of cleaner, scrub the roof surface until clean and then power wash to remove debris and continue rinsing until all suds are gone.

GacoPro GacoWash

Biological Control: Areas of algae, mildew or fungus on the roof membrane or the existing coating should be treated with a solution of 1 part household bleach and 3 parts water, followed by a power washer rinse using clear water.

Drying: After cleaning and rinsing the roof, ensure no dirt or debris is present. Allow surfaces to thoroughly dry. Examine roof, paying particular attention to areas of physical damage to determine that residual water has in fact dried before applying coating. NOTE: Drying time depends on weather conditions such as temperature, humidity and air movement.

Flat Roof Cleaning Down

Bonds to Most Surfaces (including but not limited to):

  • Aged Asphalt
  • Aged EPDM and TPO/CPA
  • Built-Up
  • Cap Sheet
  • Composite
  • Concrete
  • Fibreglass
  • Metal
  • Modified Bitumen
  • Torchdown
  • Most existing coatings
  • Sprayed Polyurethane Foam
  • Low-Pitched Roofs
  • Flat Roofs
  • Mobile Homes
  • Caravans

GacoRoof Adhesion Test Kit

If the roof has been patched with any asphalt or black tar-like products within the last 12 months, applying a coat of GacoFlex E5320 2-Part Epoxy Primer/Filler should help prevent bleed-through staining on the final coats. GacoPro Roof Coating will adhere to most surfaces without a primer; however, some substrates may require a primer for optimal adhesion. To verify adhesion, use the GacoRoof Adhesion Test Kit, which provides results in just 24 hours. If the test reflects poor adhesion, prime all surfaces with GacoFlex E5320 2-Part Epoxy Primer/Filler according to label directions.

Repair any damages, leaks, cracks with Gaco Liquid Roof Tape or Gaco Roof Tape. These products should also be used on any areas of detail or fixings to ensure any areas of weakness are protected prior to application of the GacoPro Roof Coating.

GacoPro Liquid Roof Tape

A minimum of two coats of GacoPro Roof Coating are required; recommended final film build is a minimum of 560 microns DFT. To help ensure complete coverage during application of the final coat, it is recommended to use a different colour for the first coat to create a colour contrast. Mix before application to ensure uniform colour and consistency. Product should not be thinned.

Mixing GacoPro Roof Coating

Flat roofs (less than 1:12 pitch/5°): Use a solvent-resistant 1” nap roller and depending on type of roof, dip roller directly into pail and apply, or pour product onto flat roof surface and roll out evenly, or for very smooth surfaces, pour out product and spread with an 2-3mm notched squeegee then immediately back roll for a smooth, even finish.

Pitched roofs (greater than 1:12 pitch/5°): Use extreme caution when on a pitched roofs. Follow all safety guidelines to avoid injury. Use a solvent-resistant 1” nap roller, dip roller directly into pail, and apply. A roof pitch greater than 4:12/19° is not considered walkable; Additional reach equipment may be needed to properly apply the product safely and effectively.

First Coat of GacoPro Roof Coating Light Grey

Allow the first coat of GacoPro Roof Coating to dry for 3 to 12 hours (dependant on conditions). Apply second coat as soon as the first coat can be safely walked on. The coverage rate of GacoPro Roof Coating is 2.1m² per litre for each coat on a smooth surface; coverage rate may decrease on textured surfaces, and more coating will likely be used on first coat than on additional coats. Smooth roofs can be completed in 2 coats, lightly textured surfaces often require 3 coats, and heavily textured surfaces may require 4 coats to achieve a final 560 microns DFT film build.

Second Coat of GacoPro Roof Coating Solar Reflective White

GacoPro Roof Coating can be applied in temperatures as low as 1°C and up to temperatures as high as 45°C. Do not exceed this application temperature range, or apply the coating if rain is expected within 2 hours. If any areas of the finishes roof are to be walked on for maintenance and access use GacoFlex SF2036 WalkPad in conjunction with GacoFlex WalkPad Granules to create a highly-visible rooftop walkway with exceptional durability and resistance to foot traffic and tears.

GacoPro WalkPad

Roofing contractors who are utilising an airless sprayer should consult the GacoPro Spray Guide and Safety and Storage Guide.

Once a container of GacoPro Roof Coating is opened, the curing process has started. Use the entire product on your project if possible. Allow any remaining product in the container to solidify and dispose of in the proper manner.

Application tools and equipment can be cleaned with White Spirit. If you only part use a tin and wish to keep the remainder, close can lid to store the product, over time some skinning will occur. When you next need to use the product, open the can and remove ‘skin’ which may be on top and stir well and apply.

Roof structures may settle over time. A periodic inspection of your roof, which includes transition areas, flashing, vents and skylights, is recommended. Keep drains cleared at all times. If any recoating is required over the roofs life, clean GacoPro Roof Coating and overcoat only with more GacoPro Roof Coating.

GacoPro WalkPad Granules

Approvals and Certificates

GacoPro Roof Coating Solar Reflective White meets the requirements for the Energy Star reflectance performance requirements for both low and high-sloped roofs and the requirements for the Cool Roof Rating Council.

GacoPro Roof Coating Solar Reflective White also meets solar reflectance and thermal emittance requirements for: the 2012 International Energy Conservation Code (IECC); the ASHRAE 90.1 Energy Standard for Building Except Low-Rise Residential Buildings; and the California Building Energy Efficiency Standard CEC-400-2008-001- CMF, as adopted as Part 6 of Title 24.

GacoPro Roof Coating is listed by the Underwriters Laboratory.

CAUTION: An old, neglected, or failing roof does not have the resilience to withstand the rigors of weather. GacoPro Roof Coating may not be suitable for such a roof. If you are in doubt about the condition of your roof, consult a qualified roof inspector.

GacoPro Roof Coating Approvals


  1. Our house has a foam roof, no leaks, some low slopes, some irregular surface. Would GACO sealant be suitable? Any info appreciated.

    • Hi John,

      Many thanks for the question. Provided the roof is sprayed polyurethane foam, the surface should be thoroughly cleaned prior to application. Then we would recommend 2 coats of GacoPro Roof Coating be applied to offer a waterproofing system with a 20yr Warranty.

      If you have any further questions, please feel free to get in touch.

      Many thanks

  2. The second coat of Gaco was going on mostly , but at the end it rained slightly the roofers left and I’ll be able to check this morning. They left the top of the garage not done. It is clear this morning can I go on roof to inspect and remove tape on skylights and drain, more rain is expected this afternoon.
    Please help me. I’m alone and need some answers asap

    • Hi Gwen,

      Thank you very much for taking the time to read our blog and for your question. We wouldn’t recommend you walk on the coating as this is a soft coating and it could be damaged by foot traffic.

      We would suggest you contact your contractor and ask them to come back and check/remove any tape for you and for you not to go up yourself.

      I hope this helps and please feel free to get in touch if you have any further questions.

      Many thanks

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