How to Prevent Water From Compromising the Integrity of a House’s Walls

The exterior walls of a house need to protect against moisture and exterior air or temperature penetration. Keeping your home protected from moisture and temperature will keep you comfortable and protect the structure from damage. Steps like choosing the right material, protecting it and sealing gaps are critical for moisture protection.

Sealing Openings

When a wall has been completed, it often needs to be penetrated with utility lines. These openings should be sealed with an expandable foam in the wall gap and with a flexible sealant at the exterior surface. This sealant may need to be painted and should have a high tolerance for temperature variations and sunlight exposure. In addition, walls contain other openings, such as windows and vents. No wall is completely watertight at the outer layer; some moisture will always get in. So, interior layers have to provide additional protection, and the whole wall needs to be able to breathe to allow water to evaporate.


The building’s exterior structure should serve to keep out most of the rain as it falls. A rain screen serves as the primary barrier to protect the structure against rain seepage as rain runs down the building. The cladding materials used can be stone, brick, stucco or wood. According to Mataverde Decking, there are a variety of wood types that work well as siding options due to their high density and hardwood characteristics. Finally, many cladding materials receive an additional coating of paint to provide even more protection. Any liquid coating should be UV-resistant to protect against sun damage.


In addition to keeping water out of a structure as it runs down the outside, proper drainage will keep water away from where the wall meets the ground. An additional sealant along the bottom of the building, including a plastic barrier and highly compressed soil, can prevent seepage into the building or the basement. At many points along the wall, air needs to move through to allow evaporation of any water that has penetrated the structure. However, at the bottom of the wall, all focus must be on resisting water and draining it away from the building. Water needs to run down the outside of buildings and drain away from them. Too much water inside walls can lead to mold growth and will eventually put the structure at risk due to rot. In addition, wet walls create a haven for boring insects that can destroy a structure over time.

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