How to Drain Water from a Flat Roof

A flat roof is quite a common architectural style. However, it may not always be considered a practical choice, especially for homes in the UK, where the precipitation can be quite high throughout the year. Water on the roof can collect, and start to add weight that it's not used to and that needs to be drained properly and automatically.
 

If the water remains, especially after heavy rainfall, the weight may start to affect the structural integrity of the roof, which means, that over time, the roof itself may need to be completely replaced, if it’s not properly maintained and drained after every rainfall. 

The cost of a roof is going to be much higher than the cost of installing a proper drainage system, or for those people that want to have a more manual setup. 

Clean out those drains

If your flat roof is not properly draining, the first place to check is the sophisticated draining system. Keep in mind that these can sometimes be built into the roof, so it’s important to know where the access points are. 

All that nature and debris that comes with rainfall starts to stay in your drainage pipes. These pipes need to be flushed out on a consistent basis (a few times a year) to keep the pipes clear of debris. 

There is a lot of specialised equipment that can be rented or purchased to handle this cleaning, and it's important to note that care needs to be taken with flushing equipment as if it's done incorrectly, it could damage the piping and drainage system. 

Check for pooling and cracks

If there are some areas of the roof that the water starts to make a little pond, then those places need some extra care and maintenance. Here you may need to install some roof crickets around some common problem areas such as vents or chimneys. A roof cricket is an additional slanted piece that goes around these common problem areas to help with pushing away the water. 

Another thing to consider if it's random spots on the flat roof where the ponding is happening is replacing that part of the roof. That means you may need to re-pitch some of it. Sometimes the rainwater can cause parts of the flat roof to lower (hence the pond forming) and they basically need to be reset and rebuffed out to ensure proper water drainage. 

The final piece that may need to be replaced is the membrane of the roof. This is that final sealant that closes up the roof and provides that waterproof protective sealant. These can crack over time in random parts of the flat roof and need to be maintained or even completely replaced. These are usually sealed with a high heat source so be prepared for that specialised equipment again.

Consider a professional

The aforementioned items are the least complex issues to consider with flat roofs and proper drainage. These don’t mention issues with the drainage system itself which are complex due to the structure of the roof. 

By using a professional roofer to handle the maintenance and semi-annual roof checkups, you can end up saving thousands of pounds, simply because the roofer can easily spot issues that are preventable and cheaper to fix than replacing whole sections of the roof. 



Roofing contractors will also have all the professional equipment on hand to properly drain roofs or fix sections as needed and are professionally trained to use the equipment, without causing additional damage to the roof. They are also properly insured in case something goes wrong, helping reduce the costs in the long term.