January 11, 2022

The Importance of Weatherproofing Doors & Windows, & How to Achieve

Hello 2022! We want to take a moment and thank all of our subscribers for your continued support of our blog over the last two years. Our hope is the material we have written has provided educational information not only about our products, but about the industry as a whole. For our first blog post of the new year, we dive into the importance of weatherproofing the doors and windows of your structure using silicone sealants. In addition to keeping rain and other environmental elements from entering a building, weatherproofing doors and windows can also aid to prolong the life of the structure and increase energy efficiency.

Prolong the Life of Your Structure

If air, water, or vapor were to enter a building, the results could be damaging and costly. In addition to mold and bacteria buildup caused by an increase in moisture, windows can also warp, loose shape, and develop condensation on the interior of the window. Furthermore, if a sealant that does not offer non-staining capabilities is applied to the window and door perimeter, unsightly staining and residue rundown can occur. But don’t fret, Pecora has a solution.

Pecora’s Non-Staining Technology (NST) Silicone sealants are formulated to eliminate the free silicone fluid molecules which migrate into substrates, rundown the face of the building and cause unsightly staining that is expensive to remove and creates other problems. This unique formulation maintains the sealant flexibility necessary to accommodate a building’s constant movement. Even the most expensive technology or facade substrates are safe because the root cause of the staining problem has been completely eliminated.

Traditional silicone sealants contain both silicone polymers and free fluid molecules. Silicone polymers are very long molecules designed to chemically react with atmospheric moisture. As a result, these polymer molecules become bound together and are unable to escape from the sealant.

By contrast, nonreactive free fluid molecules, which are traditionally present in order to control the modulus and other sealant physical properties, are not reactive and so remain unbound giving them the opportunity to migrate. What makes nonreactive silicone fluids so potentially damaging is their propensity to coat everything they come in contact with. Pecora’s NST Silicone sealants simply do not contain nonreactive fluid molecules which tend to migrate into the substrate and rundown the face of the building.

Pecora Corporation warrants that its products are manufactured free from defects in materials and workmanship. Pecora further warrants that Pecora NST silicone sealants will not cause porous substrates to discolor or change their appearance due to fluid migration and will maintain a watertight weatherseal for a period of twenty (20) years from the date of installation. For more information about specific criteria pertaining to our warranty program, please visit our website at

Increase Energy Efficiency

Ultimately, anything that eliminates the flow of air, water, or vapor, will also eliminate energy loss. By properly sealing the doors and windows of a structure, property owners will have the ability to regulate the temperatures inside a building. Heat remains outside during the corresponding summer months, and cold remains outside during the corresponding winter months. In addition, improper sealing can cause heating and cooling systems to overwork and increase energy costs. This could potentially lead to system repairs and unexpected expenses incurred by property owners.

How to Achieve Successful Weatherproofing of Sealant Joints

In order to achieve successful weatherproofing of sealant joints, the following parameters must be considered where applicable and designed for:

  1. “Joint Movement”—Occurs as a result of: changes in material temperature, seismic movement, elastic frame shortening, creep, live load, concrete shrinkage, moisture-induced material movement, and inadequate joint design. Joint movements must be evaluated, designed for, and accommodated.
  2. “Movement Capability”—The ± percent value that indicates the amount of movement the sealant can take in extension (+) and compression (-) from its original cured joint width. Movement capability and expected joint movement must be coordinated.
  3. “Installation Tolerances”—Depending on the substrate materials the joint opening will have a ± tolerance for its designed width which must be considered when establishing width (e.g. for a joint width of 1/2 inch in a brick masonry wall the tolerance for its width could be ±1/8 inch or more.
  4. “Sealant Selection”—Select the appropriate polymeric type for the application; however, within a polymeric type there can be a wide range in performance capabilities and properties. All sealants in that type may not perform similarly; therefore, it is important to research product capabilities prior to use.

For more information about our silicone sealants, Non-Staining Technology Silicones, or warranty programs, please visit our website at


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