As part of a 2-part series of articles we are going to take a close look at one of the most overlooked spaces of your home – the sump pit. We’ll look at what a sump is, why you have it, and the catastrophic damage that can spring up from within…but we’re getting ahead of ourselves. This article is going to be all about the sump and its reason for existence.
You house is in a constant battle with water. Your structure wants to stay dry, and water wants to go to the lowest point. It’s water’s natural tendency to go where it is not, and architects and builders know it! Underneath and around many homes is an extraordinary mechanism that use water’s predictable behavior against it.
Behold – the Drain Tile!
Funny enough it does not look like a tile at all. Drain tile is corrugated pipe with pre-drilled holes in it. Often times it is made of a very durable materials such as clay, PVC, or some other plastic. Drain tiles have perforations because it is their job to collect water from the surrounding soil and channel it into the sump pit.
Before contractors pour foundations they create a network of drain tiles in the soil first. They cover the tiles with smooth rocks, and then pour the concrete over top of the rocks to create a level basement floor. Sometimes drain tiles sit on the outside edge of the foundation as well as under the basement. The network of pipes all empty into a sump pit.
When the soil underneath and around the foundation gets saturated with water the water wants to go where it is not (it’s in its nature remember)! The drain tiles are large porous spaces that offer little resistance to the water – it welcomes it! As the water seeps into the drain tiles it makes its way away from the concrete floors and side foundation walls. This is a very good thing!
Most concrete is porous. If you have ever been on a sidewalk as it begins to rain you know this because the concrete absorbs water and changes color. Concrete can even become waterlogged. When it does it becomes extra heavy and then seeps water. If the dirt around your foundation is saturated the water can saturate your wall and then continue to go where it is not – which is out the other side into your basement. If you have even seen a wet wall in a basement or in a structure this is the cause. Its just water being water.
To make matters even worse as you go further down in the ground the pressure compounds. Hydrostatic pressure builds as you go deeper. To simplify – the water along the bottom floor of a multi-level basement garage of the skyscraper will be pushing into the concrete with more pressure than the water along a residential home’s basement wall. More depth – more pressure – more effort and engineering needed to keep things dry.
Capturing the water is just the first part. Getting rid of the water is the second part. The sump is the collection station for ALL of the fluids the drain tiles collect. It pools (literally) in a basin, that sits below the level of the basement floor. Inside the basin (sump) is a pump that turns on when the water level exceeds a certain level. The sump pump forces the water up above ground level and into a discharge pipe that carries it away from your foundation.
In the next articles we’ll look at how sump pumps actually work, why the systems fail, why some homes don’t need them, the costs of a basement flood, and the future of sump pumps.