Basement Waterproofing Sealer Explained

Routine basement waterproofing is often recommended for securing the basement against moisture seepage. Structural damage to the basement due to moisture seepage and related problems like mold development are the most common, basement-maintenance issues. Waterproofing sealers are also called masonry sealers. They are commonly available at hardware supply stores. To understand the utility of a waterproofing sealer and its requirement for your basement’s maintenance, read the following.

Understanding Waterproofing Sealer Requirement

Please understand that concrete is naturally porous to a certain extent. This is due to the presence of microscopic pores present throughout the concrete surface. These pores tend to absorb water through a slow but sustained process called capillary action. Sometimes, a whitish layer is seen on damaged basement surfaces. These lime deposits are formed due to reaction among the mineral content of the concrete mix and the moisture. Water seepage through capillary actions is hard-to-detect without seeking professional help. Even basement walls having exterior waterproofing treatments are vulnerable to such damaging, chemical reactions. Concrete has a pH of over nine, making it highly alkaline in nature. When moisture seepage happens over a sustained period, the dissolved alkalis stimulate chemical reactions that start eating into the concrete surface. This can be understood as chemical weathering of the concrete surface. Waterproofing coatings, applied when painting the walls, cannot withstand this reaction and start peeling-away. Waterproofing sealers are capable of neutralizing the alkalinity. Thus, using an effective waterproofing sealer is the only way to safeguard your basement.

Waterproofing Sealer Basics

All waterproofing sealers are a synthetic (chemically formulated) mix that can bind across a wide range of materials. Once dry, the sealer forms an insulating layer that is impermeable and doesn't crack under harsh weather conditions. Usually, the sealer is retailed in plastic cans. The packaged instructions include the ideal manner of applying the sealer. Most sealers need to be applied in repeated coatings. The entire process is slow and needs some patience. A new coating is applied only when the earlier one has dried. Waterproofing sealers have a density that is similar to wall paints. Thus, they can be easily applied using a paintbrush or a paint roller. 

Some masonry sealers are slightly expensive because they dry-out in the form a smooth layer that resembles the surface of the surrounding walls. This surface is also easier to paint. Waterproofing sealers are equally effective for waterproofing new and old basements. They can be applied to the five main types of surfaces encountered when repairing a basement—concrete blocks, poured concrete, cinder blocks, block walls and freshly-poured mortar mix. 

Spray-on application sealers are also available in the market. They are much more expensive than conventional sealers. They don’t provide the satisfaction of applying a sealer in evenly-spread coatings. However, they are effective for coating hard-to-reach places and for waterproofing areas you might not want to handle manually—like mold spots.

Understanding Curing Sealer Use

Basement waterproofing sealers are often referred to as curing sealers. A curing sealer is almost identical to a conventional sealer but it is suited for a particular type of waterproofing. Newly-installed concrete slabs in the basement suffer from a short-term problem than can compromise their structural integrity forever. This happens due to continuous evaporation from the pores in the wet concrete-mix. This form of water evaporation can often last up to a few days. Continuous evaporation of water creates a stress against the walls of the pores, stretching them permanently. This enlargement of the pores makes them susceptible to absorbing more moisture in the future. This is why curing (waterproofing) of freshly-poured concrete in the basement is vital. The waterproofing sealer binds to the pores, slowing the evaporation. Once plugged with the sealer, the pores cannot expand beyond a minimal extent. Curing sealers are better than cheaper basement sealers like wax-based sealers since they don’t harm the finished appearance of the concrete layer.