Originally published in the May 2009 issue of Concrete Today magazine.
No matter what size the job, contractors have the option of using a sealant that can be sprayed on, providing thorough penetration of concrete surfaces and protecting against moisture, toxic, mold, radon gas and airborne allergens. Pene-Seal-Crete, produced by Emecole, Inc. can be used on all concrete surfaces from basements to retaining walls.
Roy Spencer, owner Permaseal Basement Systems in Downers Grove, Illinois, has served the Chicago area and northwest Indiana for nearly 30 years. Proper waterproofing is essential for a safe and healthy basement and crawl space, Spencer said. The next step is sealing cracks in block or poured concrete walls and floors. Although poured concrete is less porous than brick and block walls, Spencer said it comes with two guarantees; it will harden and it will crack.
Keeping water out is not the only reason for prepping a basement. The basement is the source of 50 percent of the air that circulates in the living area. Preventing deadly gases like radon from rising through concrete is a must, as the quality of the air in the basement and the living area are subject to contamination from the earth below (whether the basement is an unsealed porous concrete floor or dirt in crawl spaces). Using a deep-penetrating concrete sealer prevents vapor molecules (humidity) and radon gas from passing through the porous concrete and into the home.
“Once you stop the active water seepage, then there is the vapor transmission to worry about, “Spencer said. “Radon gas can permeate porous material like concrete, and that’s where the Pene-Seal comes into play. What it does is make the concrete more dense and more resistant to transmission of vapors and gases.”
After it is mixed with hot water, Pene-Seal-Crete is applied to concrete surfaces to close off the pores in the concrete. It does this by reacting with the free lime in the concrete and forming an expanded crystalline structure beneath the surface. The crystals fill the pores, voids and cracks of the concrete, preventing penetration of radon and moisture infiltration by capillary action.
The sealant can be sprayed on with a low-pressure hand sprayer or even a garden sprayer, providing better concrete penetration, Spencer said.
“The fine mist goes into the pores better and is absorbed into the concrete more thoroughly,” he said. “Usually two coats are enough. As we apply it, we try to keep it wet for five minutes so that it’s saturated.”
Pene-Seal-Crete can be used to permanently densify, strengthen, dust proof and waterproof new and existing concrete. It is colorless, odorless, solvent free and non-flammable. Because it is not a membrane type sealer, concrete floors and walls can be painted after treatment if desired.
The sealant can be used on concrete surfaces above or below grade, interior or exterior, vertical or horizontal. The coverage rate is 200 square feet per gallon, depending on substrate composition and porosity. Applications include walls, slabs, driveways, basements, garages, traffic bearing structures, docks, ramps, pre-cast concrete elements, containment and retaining walls, and any concrete or masonry surface. It also can be used as a curing compound on green concrete, and it reduces surface dusting.
Pene-Seal-Crete is available in quantities from one gallon jugs to 55 gallon drums. Dilute in a 1:3 ratio of product to hot water, applying immediately. Do not thin with solvents. The manufacturer recommends cleaning the surface to be sprayed thoroughly, removing dirt, dust, grease, oil, waxes, foreign particles, curing compounds and from release agents for maximum penetration.
When applying, it is best to do so in moderate weather conditions, preferably in temperatures above 40 degrees Fahrenheit, avoiding direct sunlight or heavy wind and rain. Applicators should always spot test for suitability before applying.
Pene-Seal-Crete can be applied using a low-pressure sprayer, brush, roller, broom or squeegee. Apply generously over a pre-dampened surface. It is important to keep the treated area wet for a minimum of five minutes, misting treated areas that are drying to aid penetration. Treated areas should be thoroughly flushed with water, scrubbing with a bristle broom or brush; squeegee or mop dry. Under normal conditions, actual drying time is one to four hours.