FAQ: Roof Coatings & Cements

Can Black Jack products be thinned and if so, with what type of thinner?

Black Jack products should not be thinned unless labels expressly direct so. Thinning a product designed as ready-to-use can impact performance, and thinning certain products may violate government Volatile Organic Compound (VOC) regulations.

Can I apply Black Jack coatings or cements if it will rain soon?

Yes. The products designed for wet weather application include:

Can I use this on rubber roofing?

Some rubber roofing materials require special cements and coatings manufactured for use on these materials alone. Check with the manufacturer if you are not sure.

Can new built-up roofs be coated with aluminum coatings sooner than the recommended 90 to 180 days weathering period?

If an aluminum surface roof coating must be applied sooner to a new built-up roof, a water based emulsion coating should be used instead of a solvent-based asphalt coating. An emulsion coating will provide a firm base on which to apply the aluminum coating 5 to 10 days after the emulsion has cured.

How do I clean up a spilled Black Jack product?

Consult SDS data sheets for the specific products.

How soon can I coat a newly installed built-up roof with an aluminum roof coating?

New asphalt built-up roof (BUR) surfaces should weather a minimum of 90 to 180 days prior to coating with Black Jack aluminum roof coatings.

What effect does ponded water have on aluminum roof coatings?

Aluminum coatings do not perform well on roofs that pond water. Dirt can accumulate in depressions and inhibit the reflectance of the coating. If an aluminum coating is under water for a prolonged period of time, the water may work its way under the coating causing it to peel. Positive drainage is needed to flush away surface dirt and retain the reflective properties of the aluminum coating.

What factors can reduce the reflectivity and long-term durability of aluminum coatings?

Before Application: Poor Drainage, poor surface preparation, or improper mixing.
During Application: Under-applying, over-applying, or misapplying (cross-directions)
After Application: Traffic, climate and geography, or surface contamination

What is the dry or cure time for Black Jack products?

The dry or cure time for Black Jack products depends on the specific product used. Check label instructions for specific cure times. Dry time can be affected by air and surface temperature, wind, humidity, porosity of the substrate, and the type and amount of product used, among other factors.

What is the life expectancy of Black Jack’s aluminum roof coatings?

Normally, aluminum roof coatings have a service life of between 3 to 7 years, depending on the surface coated and other factors.

What should I use to mix aluminum coatings?

All containers should be stored upside down at least one day before application. Before applying, five-gallon containers of aluminum products should be mixed well using a 5-gallon stir stick or a drill with a double-bladed paddle mixer until a consistent silver color is achieved. One gallon cans can be tipped and shaken manually (do not use mechanical paint shakers) before opening, then stirred with a 1-gallon stir stick until a uniform silvery color is achieved.

Which type of roofing can I use this on? Asphalt shingles? Tar paper? Plywood?

Each product label indicates the surfaces it should be used on, for which applications, and how to use it. If in doubt, check with the manufacturer of the roofing material to ensure that any cement or coating used does not void any warranty on the roof.

Why are "Silver Shield" and "Silver Seal" not “silver” in the can– it’s gray or brown in color?

Aluminum coatings in the can are typically a bronze color. Thorough stirring will turn the product silver, but it may still have a slight bronze tone while applying. However, as part of the curing process the product “transforms” to create a bright silver film. So even while you’re applying the product, some areas will have turned bright silver while the most recently applied areas are in different stages of turning from silvery bronze to bright silver.

Why are Silver Seal and Silver Shield not a uniform color when dry?

Aluminum coatings should be a uniform, bright silver when dry. Several issues can contribute to creating a non-uniform appearance, including overlapping, improper mixing. rain, dew or snow.

Why is there a greasy residue coming off the roof after the application of aluminum roof coatings?

As the product cures, solvents evaporate and are naturally washed off the roof with rain. During dry spells, if the solvents have not been washed away, there may be a residue left on the roof surface.

Why should I use an aluminum coating to coat my roof?

Aluminum coatings can form an invaluable part of a smooth surface built-up roof (BUR), smooth or mineral surface modified roofs (SBS) or torch-down (APP) roofing systems.
Aluminum coatings form a highly reflective surface that can lower roof surface temperatures as much as 40F, which can equate in lower internal temperatures.
Aluminum coatings also protect the underlying membrane (BUR, SBS, or APP) from UV degradation, thereby helping prolong its life.

In brief, Aluminum coatings:
  •     Extend the life of the roof system.
  •     Reduce roof surface temperatures.
  •     Reduce thermal shock and stress to the roof.
  •     Make leaks easier to identify.
  •     Help the environment by reflecting heat and reducing temperature.
  •     Provide fire protection (See UL Class A Fire Ratings)

Will a roof coating stop the leaks and waterproof the roof?

For best results, all leaks and cracks should be repaired with a roofing cement and reinforcing fabric prior to using seal coating.


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The information on this site is provided as a free service. It is based on common conditions and may not apply to your specific situation. Please contact a Black Jack representative with specific questions or comments.