Outside
Yard Drainage and French Drains
Most water under a house started as rain on the roof or the yard. Yard drainage deals with it outside, before it reaches the foundation, and it is often the first thing to fix whatever else is planned.
Call (423) 555-0114Your call goes to an independent local waterproofing company.
Start at the roof
A roof sheds a great deal of water in a storm, and all of it lands within a few feet of the foundation unless something carries it away. Clean gutters and downspouts that discharge well out into the yard solve more wet crawl spaces than any other single change. Extensions can run on the surface or be buried and brought out lower on the lot.
Then the ground
Soil beside the house should fall away from the wall. Over the years beds get built up, soil settles next to the foundation and patios tilt, until the ground slopes the wrong way. Regrading means adding and shaping soil so rain runs off. The soil must stay below the siding and below any crawl space vents.
French drains, swales and catch basins
- What it isFrench drain: a trench with a perforated pipe in stone
- When it is usedTo intercept water moving through the soil, for example across the uphill side of a house.
- What it isSwale: a broad, shallow channel in the lawn
- When it is usedTo steer surface runoff around the house where there is room.
- What it isCatch basin: a grated box tied to a buried pipe
- When it is usedTo empty a low spot that ponds, such as the foot of a driveway.
- What it isDry well: a buried pit of stone
- When it is usedTo let water soak away where there is no lower ground to send it to.
Where the water ends up
Every drain needs an outlet, and the outlet is the part most often left vague. Ask to be shown on the ground where each pipe will end. It should finish on your lot, at a point that does not send water onto a neighbor or across a sidewalk.
Within Kingsport, the city looks after drainage in the public right-of-way and in public easements. Pipes and ditches on private lots are the owner's to maintain. If water reaching your yard comes from a street drain or a city ditch, the city's stormwater page gives 423-229-9454 as the number for drainage problems.
Before anyone digs
Trenching for a drain crosses the same ground as buried utility lines. Tennessee 811 must be notified ahead of time, and lines you own yourself, such as power to a shed or a sprinkler system, will not be marked by the utilities. Tell the company about any you know of.
Questions to ask
- Where does each pipe start and end? Can you mark it on the lawn?
- How will the pipe be kept from filling with silt and roots?
- Are there clean-outs, so a clog can be cleared without digging?
- Will the lawn be put back, and by whom?
If water still gets in after the yard is corrected, the next step is inside: crawl space repair or basement waterproofing.