Drainage and Moisture Correction: Fixing the Cause First

Why water moves foundations

Clay soils common in parts of Louisiana typically change volume with moisture. They can swell after a wet stretch and shrink and crack during a dry one. A foundation sitting on that soil moves with it — and rarely evenly. One corner gets roof runoff every storm while another sits under a tree that pulls water out of the ground. The result is differential movement: one part of the house rises or settles relative to another, and that is what cracks walls and tilts floors.

Water management cannot change the soil, but it can reduce how hard the soil swings between wet and dry right next to the house. That is the goal of drainage and moisture correction: keep water away from the foundation, and keep the moisture level under and around it as steady as practical.

The usual drainage fixes

Gutters and downspout extensions

A roof sheds a lot of water in a Louisiana downpour, and without gutters it lands right at the foundation line. Gutters that are missing, clogged, or undersized, and downspouts that dump at the corner of the slab, are among the first things a specialist should look at. Extending downspouts several feet out, or tying them into a buried line that discharges away from the house, is often the simplest fix on the list.

Grading

The ground around a house should slope away from it. Over the years, flower beds get built up, soil settles against the slab, and patios or walkways end up tilted toward the house. Regrading restores that fall so surface water runs off instead of soaking in at the foundation. Ask the specialist how much slope they are building in and how far out from the house it extends.

French drains and surface drains

Where grading alone cannot move the water — a low side yard, a neighbor’s runoff, a lot that sits lower than the street — a drain may be needed. A French drain is a trench with perforated pipe and gravel that collects water and carries it somewhere it can discharge. Surface drains and catch basins handle water that collects on top. Both need a real outlet; a drain that has nowhere to empty just moves the puddle.

Crawlspace moisture for pier-and-beam houses

On a raised house, water that pools in the crawlspace keeps the soil under the piers soft and keeps the framing damp. Over time that can mean settling piers and rotted sills and beams — the exact problems pier-and-beam repair exists to fix. Moisture work under a raised house can include correcting where water enters, a ground vapor barrier, and improving ventilation. Which of those fits depends on the house, so ask the specialist to explain the choice.

Why drainage gets its own line on the quote

A good foundation quote separates the work into lines you can read and compare. Drainage is one of them — not a footnote inside the structural repair. Every foundation quote should itemize these four lines separately:

1. 1Evaluation findingsWhat was measured and found — elevation readings, crack locations, construction type, likely cause.
2. 2Drainage / moisture correctionGutters, grading, downspouts, or crawlspace moisture work that addresses why the soil is moving.
3. 3Structural repairPiers, shims, or sill and beam replacement — with counts, locations, and depths stated.
4. 4Finish / cosmeticDrywall, brick, trim, and door adjustments after the house moves — priced on its own line.

Keeping drainage separate does two things for you. It shows whether the specialist actually addressed the cause, and it lets you compare bids fairly. One quote may include regrading and a French drain; another may leave them out and come in lower. Without separate lines, those two bids look like a price difference when they are really a scope difference.

Published ranges for drainage correction run $1,500 to $6,000. If a drainage line falls well outside that, ask what it includes. The full table is on the foundation repair cost page.

The common failure: fixing the structure, not the water

A house can be piered and lifted, and if water keeps pooling at the same corner, the soil around the new piers keeps cycling and the unsupported parts of the foundation can keep moving. The repair gets blamed when the cause was never touched. The reverse also happens: a homeowner spends on gutters and grading for a house that has already settled and needs structural work. Neither half works well alone when the house needs both.

That is why the evaluation should answer two questions in writing: what is moving, and why it is moving. If a quote only answers the first one, ask about the second.

What to check around your house before an evaluation

• Where do the downspouts empty after a heavy rain? Walk the house during or right after one.
• Does water stand against the slab or under a raised house for a day or more?
• Are flower beds or soil built up above the edge of the slab?
• Do patios, walks, or driveways slope toward the house?
• Is the crawlspace damp, musty, or holding water?
• Are there large trees close to the foundation?

Photos of what you find help whoever does the evaluation. If you see standing water under the house, that is worth calling about — the FAQ covers what happens after you call.

Questions to ask the specialist

• What is causing the movement, and how does this quote address it?
• Where will the water go after your drainage work — what is the discharge point?
• Is the drainage work priced as its own line?
• Should drainage happen before, after, or alongside the structural repair, and why?
• For a raised house: what is the plan for crawlspace moisture?

Drainage jobs on their own commonly land between $1,500 and $6,000 in published ranges, which makes them one of the smaller lines on most foundation quotes — and one of the most important.