Crawl Space Drainage Repair
Northwest Crawl Space Services specializes in residential crawl space drainage repair and sump pump installation services.
Water in your crawl space can be very destructive – even more so than rodents. Standing water in a crawl space can cause mold growth and compromise the entire foundation, necessitating expensive repairs. It’s essential to identify water issues in your crawl space early, and to install professional drainage systems for ground water.
Here at Northwest Crawl Space Services, we specialize in the installation and the maintenance of crawl space drainage systems that combine French drains and sump pump systems to keep your crawl space dry.
What are some reasons rain or ground water can enter your crawl space?
High Water Table: Water tables can become elevated when they receive more water than they drain off. This can be from unusually high amounts of rain or excess water from higher elevations. High water tables are often above the level of basement floors or crawl spaces, frequently leading to flooding in these areas.
Downspout Drain Failure: A faulty downspout system can result in excessive amounts of water near the foundation, which will encourage water seepage into the crawl space.
Foundation Drain Failure: Almost every house, old or new, has a foundation drain. Its purpose is to keep water out of the foundation/crawl space. When it fails as a result of a clog or is overwhelmed by a large amount of water, water seeps into the crawl space as well.
What are some signs of water damage in your crawl space?

French drain install in crawl space as part of a sump pump project
Most residential wood foundations aren’t built to handle water or excessive moisture. When water soaks into untreated wood, any of the following can occur:
Rotted Wood: This is actual structure damage that requires foundation repair or replacement.
Mold and Mildew: The growth of fungus that can be toxic and allergenic, and cause additional damage to the wood.
Foundation Settlement: The primary cause for foundation settlement and sinking is standing water or saturated ground.
Wood Destroyers: Water in the crawl space leads to elevated moisture levels, which causes dampness in the wood structure. Damp wood attracts carpenter ants (secondary wood destroyers) and even termites (primary wood destroyers), both of which can quickly create major structural damage.
Our Crawl Space Drainage System Set Up & installation Procedures:
Step 1 – Cleaning and drying: Removal of existing vapor barrier, debris and standing water.
Step 2 – Catch basin install: We determine where the lowest spot of the crawl space is, dig a hole, and install a professional, reinforced plastic backfill basin that’s perforated and filtered, with a layer of lava rock surrounding it.
Step 3 – Sump pump install: Next, we install a high-quality cast-iron sump pump into the basin. Sump pump size varies from ¼ horsepower to 1 horsepower and is determined by the distance it needs to pump out and the speed of water filling the basin.
– Additional options include a sump pump with battery backup system, backup pump, flood alarm system and more.
– Every pump system is equipped with a check valve to prevent water from flowing back into the basin.
Step 4 – Discharge Drain Install: We use hard PVC pipes to channel the water safely from the basin outside of the crawl space. Depending on your needs, we can route this drain into a street drain, downspout drain or a free-flow slope.
Step 5 – French Drain: With the assistantce of small shovels and rotary hammers, we meticulously dig a trench around the entire interior perimeter of the crawl space. Inside the trench we install a 4” perforated pipe covered with a sock. The entire trench gets covered with drain rock, and the two ends of the French drain pipe go inside the basin to channel the collected water into it.
Upon project completion we clean the basin, run tests and quality control, and install a new vapor barrier to cover the ground and keep moisture from entering the crawl space.