How Elastomeric Paint Prevents Water Penetration, Eliminates Cracks and Offers a Durable Line of Defense for Exterior Finishes

Zumbrunnenby Daniel J. Williams, Senior Project Manager, zumBrunnen, Inc.

Water penetration is a building’s worst enemy. Stucco, exterior insulation finishing systems (EIFS), concrete and masonry are prone to cracking in climates with extreme temperature changes, and if water penetrates these cracks, serious and costly repairs often result. One great preventative maintenance product for exterior stucco, EIFS, concrete and masonry walls is elastomeric paint.

Unlike traditional paint, elastomerics form a durable, tough film that provides a waterproof barrier to almost any exterior surface. It is a thick, high-fill paint that is flexible and stretchable, so it is ideal at bridging non-structural cracks, joints or defects from hairline up to about 1/16-inch wide. Larger cracks require joint preparation and application of a compatible joint sealant.

All buildings need to be painted every 7-10 years, and hairline cracks need to be touched up as they appear. However, with regular paint, cracks will come back and may allow for water penetration between touch ups. While elastomerics are more expensive than high-quality commercial and residential paints, they offer superior durability and a waterproof barrier making them a wise choice for added protection.

If a building’s weather barrier is intact, water that penetrates the exterior finish should weep out of a properly designed exterior finish system. If there are any deficiencies in the weather barrier, significant damage may result. Therefore, it is imperative to inspect exteriors and fix any barrier deficiencies. Here is a quick waterproofing checklist:

  1. Are there hairline cracks in the exterior?
  2. Is caulking and/or joint sealant intact or separating from EIFS or other masonry material? Check horizontally and vertically, and check at the floor line for each floor.
  3. Are there water stains or signs of mold windows, floor lines, ceilings or in the corners?

Damage must be repaired before sealing, or the problem will become worse. If you are unsure about the level of damage, a firm such as ours or a waterproofing contractor should help you assess the damage and fix the problem.

Daniel J. Williams is a Senior Project Manager with zumBrunnen, Inc. He holds a B.A. Degree in Civil and Environmental Engineering from the University of Wisconsin. He has over 28 years of experience in helping clients prevent and solve construction-related issues.

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