When someone coined the phrase, “The only sure things in life are death and taxes,” they forgot about moisture. It’s an integral part of our atmosphere that is often a welcome friend, but it also can show up suddenly, uninvited, like an out-of-work uncle.



This high-end bathroom is protected by an easily applied waterproof membrane.

Moisture is particularly troublesome when it seeps into buildings and residential structures. Varying in degrees from slight wall dampness to window condensation, to puddling water, it can wreak havoc with lumber, sheetrock, concrete, tile, carpet and many other vital materials found inside a home or commercial building.

Tracking the Culprits

The sources for moisture would fill out a convincing police lineup. One of the most obvious is rainwater, which can seep into the house through the foundation and come up through the slab. It can also enter from the roof or through wall cracks. High humidity can be another factor that, in some regions of the country, is unavoidable. But among the most overlooked culprits are people and their daily in-house routines. Bathrooms, laundry rooms and kitchens provide some of the primary spaces where many of these moisture-generating activities occur. When you think of the constant moisture damage from a leaky toilet, a faulty supply line or a shower door that doesn’t close properly, you might as well view that drip, drip, drip as dollars going down the drain, because the expense of repairs can be long term, especially if you eventually have to replace the subfloor. The ounce of prevention that is provided by a good waterproofing product can eliminate the high costs of a cure.

Not only can moisture accumulate around areas such as sinks, showers and toilets, but it can also appear near washers, dryers and refrigerators. But remember, it’s not just the small child splashing in the tub or the broken hose on the back of the washing machine that require vigilance. It’s the entire home, because anywhere there are pipes, wall seams, shingles, slabs or windows, a potential problem can soak your pocketbook as a homeowner or dampen your good reputation as a construction professional. And when you consider that long-standing moisture can lead to insidious mold problems, a potential health risk, you could face the possibility of litigation from those harmed by its ill effects. No builder, remodeler or flooring installer wants that very expensive headache.

Creating a Balanced Defense

So where do we draw the line of defense, especially since we know that water and moisture are so unrelenting? The primary concern should be around bathrooms and kitchens, plus entry points such as windows, doors and deck areas located adjacent to or over occupied spaces. Your plan for protection should be a balanced system, so don’t forget those all-important floors, foundation and slab. As a provider of waterproofing and crack isolation membranes, flooring and underlayment products for the tile and stone industry, we have seen firsthand the value of good moisture prevention in those areas.

It is important to consider the permeability of the construction materials used throughout the structure. Gypsum board and concrete, for example, can have high permeability ratings, making them natural absorption areas for moisture. On the other hand, low permeability materials such as latex paint, glass, polyethylene plastic and metal act as strong vapor barriers.

There are many good moisture preventive options out there, but some are better than others for particular situations or applications. Products such as mold-inhibiting crack isolation and waterproofing membranes can provide excellent moisture-blocking characteristics. Our research and experience led us to develop a crack isolation membrane that not only isolates sub-floor cracking under tile or stone, but also works effectively as a moisture barrier under vinyl, hardwood and carpet on a slab foundation. We found it equally important to provide over 800 percent elongation and to ensure performance that exceeds ANSI  A-118.10. By including a proven anti-microbial additive that inhibits mold and mildew, we have been able to establish several different layers of protection.

One manufacturer has been touting a clear penetrating sealer that works as a breathable moisture barrier for masonry block, pre-cast and poured concrete foundation walls. Meeting the environmental requirements of the damp-proofing industry, it can be applied, in one step, to dry or damp walls. According to the manufacturer, there are no grade-line problems as associated with tar; it is odorless and unaffected by ultraviolet rays.

When in Doubt, Waterproof It

In instances where the moisture is more prevalent and a vapor barrier is insufficient, an airtight waterproofing system may be needed. Waterproofing compounds can have a variety of properties. They may be urethanes, modified asphalts, clay-based or rubber-based products. Good waterproofing systems, however, have one thing in common…ground water has little or no long-term impact on them. They usually maintain good elasticity and can even bridge small foundation cracks.

Mer-Krete has developed several highly effective waterproofing solutions for the tile and stone industry. One of our load-bearing waterproof membranes, applied in a cold, semi-fluid state, includes an asphalt modified latex material reinforced with a synthetic fabric. Another, composed of a modified elastomeric copolymer, provides a 100 percent waterproof coating in a single liquid application. Not only are these highly effective load-bearing membranes waterproof, but they will also limit the transfer of substrate cracks to the-finished overlay. They can be applied to practically any form or irregular shape, including base flashing, parapets and walls.

For below-grade exterior foundation walls, consider a membrane that not only forms a seamless, impermeable shield, but also resists the fungus, algae and bacteria often encountered in these areas. It should be a product that also maintains its performance properties when exposed to chemicals and gases commonly found in soils. One particularly intriguing innovation now on the market is a plastic, dimpled material that, when installed between the outside soil and exterior insulation, creates air channels that allow air to dry out the concrete and insulation in the event that water seeps into the wall.

Exterior areas such as balcony decks, patios and various outdoor surfaces located over occupied spaces deserve attention, too. It’s wise to choose a product that acts as both a waterproofing agent and a crack isolation membrane. Ideally choose one with a synthetic fabric or other reinforcement material to enhance its water protecting performance. I always remind installers to make sure they select a product that does not cause height problems at the doorway.

A Strategy That’s Code-Ready

Whether the problem is one of dampness, moisture vapors or a full waterproofing challenge, be sure to choose a solution that conforms to code requirements, meets all ANSI standards and features a solid warranty backed by a reputable company with years of experience. And make certain that you know the extent of the moisture obstacles you are facing. While damp-proofing is economical and effective as a means of retarding water intrusion, it is in no way a true waterproofing membrane. Damp-proofing products generally become brittle once they dry and can actually be dissolved by water over a period of time. Waterproofing membranes, on the other hand, can bridge small foundation cracks, retain their elasticity and provide self-sealing properties that are unaffected by long-term exposure to water.

While we ourselves may need water for sustenance, the structures where we live, conduct business and store our valuable items do much better in a dry condition, free from the caprices of moisture. Water will always be around us, and that is a good thing. But with improving technology, it can be controlled in ways that keep it from becoming problematical. By recognizing where those trouble spots may be and taking precautionary steps, before moisture infiltration occurs, you can confine the water to the backyard pool where it belongs.