Top 3 Flat Roof Drainage Solutions | Exeter Roofing

Flat roofs can be a blessing or a curse. Those who are lucky enough to live in hot countries can use them as locations for picnics, romantic dinners or simply to chill out under the stars. But for us, here in Britain, flat roofs can be known for dodgy drainage. But there’s always an answer! Check out our flat roof drainage solutions. Minimise the damage to your building and stop those pesky pools of water. You’ll be ditching the bucket in the middle of the living room in no time.

Interior Drainage Systems

It’s perhaps inaccurate to talk about ‘flat roofs’ since many are subtly sloped either towards the edge or towards an internal drainage system. These are drains connected to pipes which stop water from ‘ponding’ or ‘pooling’ in the centre of the roof and guide it directly into sewers.


  • Aesthetically pleasing and unobtrusive, interior drains are invisible and retain the exterior image of the property.
  • They can be designed into an architect’s plan for an extension, meaning less hassle when building a new section of the property.
  • They are stronger, longer lasting, and more robust than many guttering solutions.


  • Of all flat roof drainage solutions, these are the most expensive to install, and also to fix; if the internal pipes get blocked, they will need an expert.
  • Interior drainage systems use filters to select drained material. The best filters will allow smaller pieces of material through, in order to avoid filter-blocking. This means that large debris will build up over time, and will have to be periodically cleaned away.


Gutters guide excess water down the side of a building and deliver it to the drains. They also help to maintain the cladding on a building. Perhaps the most typical when it comes to flat roof drainage solutions, nonetheless it’s important to get good quality gutters fitted and installed for their optimum usage.


  • There are various materials available (steel, copper, vinyl etc.) which allow the gutters to more easily blend into the building’s individual style.
  • Best for small roofs as they are efficient at handling smaller amounts of water.
  • Cheaper option depending on the material chosen.
  • The pipers are unlikely to freeze (even in British weather!)


  • With heavy flows of water, these are less effective because they are more prone to clogging with debris.
  • You may have to test downspout size to find the optimum size to stop clogging, whilst allowing smaller particles through.
  • Ice buildup in cold weather can result in a blockage to these flat roof drainage solutions, causing water to pool in the middle of the roof. This can cause strain, especially if it turns to ice.


Scuppers are simple yet effective drainage aids, designed to feed the water through parapet walls, in order to more effectively flow down downspouts and gutters. Typically, they will operate in conjunction with a sloped roof, optimising collection of rainwater at the lowest points.


  • They are mid to low cost.
  • This form of flat roof drainage system is less a system, more of a well-designed accessory, though they can be used in the absence of gutters to simply pour the water away. They will need to be installed with a good gap between the wall and end of the scupper to avoid unsightly splashing.
  • Scuppers are a good backup solution to other systems when they become blocked.
  • They are useful for getting around (or through) parapet walls which stop water falling from a sloped roof.


  • Scuppers are flat roof drainage solutions that are more likely to ice up.
  • A smaller scupper can clog; it’s better to look for a wider one, especially if your roof has tree coverage.
  • Without a gutter system, they can cause splashing and erosion on the ground below.

Which is best for your roof?

The slope of a roof is a key aspect to consider. Without a slope, gutters and scuppers are needed to effectively gather the water. If not, there are more flat roof drainage solutions available to sloped roofed properties. It is possible to add a slope to a flat roof – check building regulations, as some can be 2% slope minimum.

Check out our roofing solutions or get in touch with us today for more information.

All roof work undertaken

Fully qualified for heritage tiling & repair

Fully qualified in traditional roofing works

Contact Us

Make an Enquiry