Waterproofing the exterior of a house that's under construction is relatively simple because the foundation and/or basement walls of the home are already exposed. The construction allows you (or the contractors, rather) to waterproof as much as needed with little disruption to the construction process. It's quite a different story when the house is already complete and the landscaping installed—especially an older house with established landscaping. That process involves excavating the soil around the home and is more time-consuming and disruptive—but that waterproofing needs to be done, and it needs to be exterior, not interior.

Interior Waterproofing Doesn't Stop Moisture From Breaching the Exterior Surface

You can add waterproofing to different layers of a wall, from the outside to the inside of the wall to the surface of the wall inside the home. Waterproofing will stop moisture from crossing that boundary, but it won't stop moisture from getting into parts of the wall not protected by another layer of waterproofing. If you add a waterproofing membrane to the inside of the wall, moisture can still breach the surface on the outside of the house. The moisture can then cause problems that may spread around the house, and even into the house.

Mold Knows No Waterproofing Bounds

One big problem when moisture breaches a wall is mold, and unfortunately, mold really doesn't respect any waterproofing boundaries. Mold is one problem that could still spread into the house even if there were waterproofing layers in the middle of the wall. The best way to prevent mold from forming due to the presence of moisture in the wall is to waterproof both the outside of the wall that's exposed to soil and the inside surface of the wall that you see in your home. If you're waterproofing a foundation, the waterproofing needs to be on the surface of the foundation that is exposed to soil and weather.

You Don't Need Rain to Have a Water Problem

Something people often forget is that rain and snow aren't the only sources of moisture that could cause a problem for your foundation or basement walls. High water tables and poorly aimed sprinklers are also sources of moisture that could lead to moldy walls and leaks. And even well-placed sprinklers, if the soil has to be kept moist for certain plants, can be a problem.

As long as the soil touching the house is wet, you have a source of moisture that requires you to get external waterproofing for your home. If your home is not already externally waterproofed, please start getting bids now, before any more moisture soaks into the walls and foundation.

Contact a residential exterior waterproofing contractor for more information.