Hydrostatic drain testing for Houston slab homes

Foundation repair companies in the Houston area commonly ask for a hydrostatic test before they level a house. There are two reasons. A leaking drain can soak the clay under the slab and be part of why the foundation moved in the first place, so fixing the foundation without fixing the leak invites the problem back. And lifting a slab puts stress on the drain lines underneath, so a baseline test before the work shows what condition the pipes were in. We send the results in writing so the foundation company and you have the same record. If the test fails, the repair, often tunneling under the slab, is usually done before the leveling.

Buyers ask for this test when the inspection notes foundation cracks, sloping floors, past foundation repair or an older home with cast iron drains. Sellers sometimes run it first to have the results ready for buyers. The test is the same, but timing matters because option periods are short. We need the water on, a reachable cleanout and the house unoccupied for the test window, since nobody can use a sink or toilet while the drains are full. The result is a pass or fail with the amount of drop measured, which buyers can take back to the negotiation. A failed test often leads to a camera run to price the repair before closing.

After a leak under the slab has been repaired, or after the house has been leveled, a retest confirms the drain system holds. This is the step that closes the loop for the foundation company, the buyer or your records. We run the same test as before, plugged at the same point and filled to the same height, so the results compare directly. If the earlier failure was on one branch, we may test that branch on its own first. A pass here is the point at which tunnels get backfilled and floors get put back. If the line still drops, we isolate again, because a second leak sometimes hides behind the first.