Cellar Below Water Table

[TxBrew]

Is it possible to do a cellar or really a basement if the basement/cellar has a portion below the water table?

 

[Runningwolf]

I'm not an expert but my guess would be probably not. I'm not sure even a sump pump would keep up or it would cost a bundle keeping it going. Some folks will do a raised basement under there house where maybe 4-5 courses of blocks are above ground and the rest under ground.

 

[Dugger]

Anything is possible but this sounds like it would be very difficult and very expensive. A lot depends on your soil conditions and drainage possibilities but the hydrostatic pressure would be hard to overcome. It would be best to talk to a competent local contractor to see if any have been done in your area and explore the options.

 

[pjd]

Water always wins! You can count on that.

 

[grapeman]

That depends on what you consider the water table. If you mean the level that the water seeks out almost year round, then I would not try it under those conditions.If you mean the level the water is likely to rise to once a year or so, then yes it is possible and often done. When you do a deephole test, you can see the line considered the water table because the soil is a darker color there because the water moves clay, etc there and leaves that mark. With a good solid foundation of say 8 inches of poured concrete it is very much possible. You lay crushed stone under the foundation and floor at least 6 inches deep. Install a perimeter tile drain that comes to a sump hole or if possible a daylight drain (pipe exits out a sidehill so the water always drains away). You also need to apply a water proof material such as tar to the outside or even better install a waterproof membrane over the walls exterior. With those conditions, the basement will remain perfectly dry unless you have a once in a hundred year event such as Irene was last year here where the ground gets saturated and remains that way for weeks. The water would possibly leak through under those conditions.

Most houses around here are built on less than perfectly drained sites and these methods work very well. Even more expensive mthods such as Wade had installed a few years ago will work well also as a retrofit.While I am not a contractor, I have a degree in Soil Science and also do Residential Drafting of house plans and include such basements in the majority of new builds.

 

[Wade E]

Our house is basically under the water table on the front side as this whole town was built on swamp land but our yard is graded. The front is about 5' under ground and the back is a level walk out. Without proper drainage and a sump I literally had water springs shooting up through cracks in my floor and it would also seep through walls in a few spots. Spent $6500 after about 2 years of living with that! 2 house inspections and neither caught that.