How to Prevent Basement Flooding

A flooded basement can be a very expensive problem to rectify. Not only is there the cost of hiring the machinery needed to pump the room dry, but there is also the potential damage to possessions and the foundations of the property too. Even if this is covered by home insurance, flooding is one of the most significant factors taken into account when placing a figure on annual premiums – so it really does make sense for those with basements in flood prone areas to do what they can to prevent flooding occurring in the first place.

The good news is that there are a number of standard ‘golden’ rules when it comes to preventing a basement from becoming prone to flooding, ranging from the very basic to the rather more technical. There are a number of stages to this, which we shall now outline below.

• Why do basements flood?

It must be remembered that water is drawn to the earth by gravity and that it will always take the path of least resistance. In layman’s terms – it will always go downhill, regardless if a house is in the way or not! Almost always this water will come from rainfall, but in extreme cases it can stem from streams or rivers breaking their banks during a flood, or even a burst underground water pipe.

• Examine the grounds around the property

The first thing that needs to be done is to take a careful walk around the property looking at what angle the ground is at when it makes contact with the walls. If the soil/grass is angled towards the property at a slope then this will need to be addressed because obviously it will channel any excess water directly at the walls. This is one of the most common reasons why basements flood – it can take years for the water to finally sink down and seep through the basement, but it is sure to eventually occur.

When it rains, look to see where puddles form – if water is starting to mass around the bottom of a downslope, then preventative action will need to be taken sooner or later. Also, in heavy rainfall, take a look at the gutters (more on which shortly) and see if they are overflowing close to the puddle.

The solution to this is usually to landscape the grounds so that they face away from the property. Other options in more extreme cases, or where landscaping may not be possible, are to install ground drains that will draw the water along the house to an angle where the water will naturally flow away from the property, but this is rarely the best method for total prevention.

• Examine the gutters

Most modern houses are built very much with ground drainage in mind, it tends to be more of an issue in older homes or those situated in areas prone to erratic flooding. Water breaking into the basement is far more commonly caused by an issue with the gutters. When they overflow, they deposit the excess water almost directly next to the foundation wall below – causing puddles that once more will seep into the ground next to the basement walls. There are three factors to consider here:

Blocked downspouts are a common cause for causing gutters to overflow as over time they have a tendency to become blocked by debris (leaves etc.). Also they are commonly very thin and struggle to manage large volumes of water in heavy rainfall. In turn this causes an overflow of water that will hit the walls and seep down towards the basement. This can be addressed by either regular maintenance or installing an oversized downspout.

Clogged downspouts occur when the downspout is at an angle rather than a straight vertical drop. The solution is either to install a strainer or replace/realign to a better position.

Poor gutter slopes will tend to eventually become shallow in the middle over time and limit the flow of water towards the downspout. This causes water to overflow – the solution is simply to correct the slope and clean out the debris.

• Blocked drains

A blocked drain will inevitably cause a large amount of water to form a puddle around it. The problem however is what the eye cannot see – beneath that puddle there will be much more water, the pressure of which will be forcing its way against the basement walls. This is a common cause for basement flooding, but fortunately one of the most straightforward to diagnose and address.

Almost always the cause for this blocking is an excess of sediment, leaves, twigs etc. that may only cause an overflow in more extreme rainfall. Even if this is the case, it should be addressed because the problem will only grow worse. Sometimes it is possible to ‘muck’ these out by hand, but if the problem goes too deep the service of a drain cleaning company will be needed to pressure hose the drain clear.

Keeping an eye on drainage around the property is essential in keeping a basement safe from flooding and damp. Remember to look down the drains, along at the lie at the land, and up at the guttering and any overflow pipe or pipes that you may have and it should be a straightforward task to identify any issues before they become too serious.