Many buildings suffer from flooding at certain times of year, especially in basements built below the level of the water table. To alleviate this particular problem, common in buildings situated on flood plains, architects usually include a sump pit in the floor. This collects the excess water, pumps it outside, and keeps the rest of the room dry.

In principle, this sump is a simple and effective solution, but the resulting standing water is often filthy, harboring dangerous microbes and providing a place for mosquitoes to multiply. The solution to this problem is easily solved, by installing a sump pump, which drains this water and ejects it into the sewage system.

Sump pumps come in many shapes and styles, and it can be difficult to pick the right sump pump for the job. If your basement floods periodically, hiring a sump pump, when required, is the cost effective solution. If flooding is a frequent and severe problem, buying a sump pump is the best choice; this guide will help you to find the best type for your needs.

The most important factor, when choosing from amongst the huge range of models, is the horsepower. You need to ensure that the motor has enough power to keep up with the inflow. Unless you need to raise the water a long way, or your flooding problem is particularly acute, a ½ horsepower (400W) motor provides more than enough power.

A sump pump should incorporate a floating valve, which will start the pump automatically when the water level rises above a certain point. This important feature ensures that the pump will kick into life, even if you are not at home, saving your property from serious damage. A couple of hours of floodwater is sufficient to damage walls and foundations permanently, so this automatic start is absolutely essential.

The capacity of the pump depends upon the amount of water moved and the vertical height needed. Capacity is measured by the amount of water moved per hour, and you should err on the side of caution. A ½ HP pump will happily raise water 25 feet vertically, and will move 2000 – 3000 gallons of water every hour, which is adequate for most situations.

However, this is not the only important factor, and you should check for the simple things that can make a huge difference to efficient operation. Ideally, the pump should incorporate a one-way valve, preventing the water from backing up. For a higher rate of pumping, the hose should be wide and robust; this, coupled with mesh over the intake, will prevent debris from entering and blocking the mechanism. If you decide to invest in an electrical pump, you should make sure that you have a back up generator, to provide uninterrupted service if the power supply fails.

Pedestal sump pumps are the most permanent type and, whilst ugly, are robust and reliable. Pedestal sump pumps consist of motor sitting on a pedestal, which is fixed to the floor of the sump pit. This keeps the motor safely out of harm’s way, and guarantees safe and uninterrupted operation. Pedestal sump pumps incorporate a floating ball valve, so check that this is robust and operates smoothly.

Pedestal sump pumps are inexpensive but are ugly and obtrusive, so are most commonly fitted in basements where flooding is a recurring problem. Pedestal sump pumps are extremely robust and easily maintained, so a good model will give many years of uncomplaining service.

Submerged sump pumps are waterproof and are fixed to the bottom of the sump pit, sucking water through the body of the motor. Submerged sump pumps are less obtrusive than pedestal sump pumps and are an excellent option if space is limited, or you want the pump to be unseen and quiet.

Submersible sump pumps safely operate for longer periods than the pedestal type, without burning out the motor, and are more efficient. The major disadvantages are the price and the durability; a leak in the casing will risk short-circuits and permanent damage, so buy a strong and robust model.

Portable sump pumps are the cheapest of the options and are perfect when flooding is an infrequent event. They can be stored away and deployed when necessary, although they can be underpowered when compared to the permanent types, and cannot run for long periods. The other danger is that they are not always fitted with a valve, so it is crucial to ensure that they are turned off before the sump empties. Allowing your portable sump pump to run dry will soon burn out the motor.

Sump pumps are essential for any basement that is at risk from flooding. The exact type of sump pump depends upon many factors, including the frequency of flooding, the volume of water and the available space. If you are unsure, your local supplier will be happy to help you select the best option from amongst the array of options.