The Best Drainage Solutions For Your Flat Roof

August 11, 2023

The Best Drainage Solutions For Your Flat Roof

Having drainage for your flat roof is essential. Compared to sloped roofs, flat roofs need efficient drainage to ensure water doesn’t build up over time. Excess water buildup has the potential to destroy your existing roof and cause serious damage to your home. When ponding begins to occur, it’s clear that your flat roof has too few drainage solutions.

Not only can water damage be harmful to the existing flat roof structure, but it can also cause leaks within your home, eventually destroying your interior and causing an array of other tedious problems. Without an adequate flat roof drain in place, your home won’t be protected.

Generally, having a flat roof installed isn’t a big risk to take. In comparison to more traditional roof types, flat roofs come with a higher chance of flooding, but if they’re installed correctly by professional roofing contractors, there should be the right amount of drainage to ensure no issues occur. To find out more about the best drainage solutions for your flat roof, continue reading.


Why Does Drainage Matter?

Drainage helps to prevent water from pooling on your flat roof, as well as eliminating any chances of moisture or unwanted debris from building up. Over time, a flooded flat roof will cause you hassle – often resulting in having to pay costly figures to fix your entire roof structure or any other additional damage to your home.

Typically, flat roofs have a built-in drainage system that ensures water can flow away freely over long periods. Additional debris can be hard to manage, especially if you’re unable to keep on top of flat roof maintenance. Having a drainage system helps in many ways – it’s vital to make sure a reliable, long-lasting drainage solution is put in place during your flat roof project.


Types of Drainage Solutions for Your Flat Roof

There are plenty of drainage systems that you can put in place to ensure your flat roof can remove water most efficiently. From internal drains, scuppers and gutters to name a few, there’s a plethora of options to choose from; it’s all about finding what works best for your roof structure. Let’s take a look at some choices to consider in greater detail.


Internal Drains

Internal drains are installed underneath your flat roof, connecting to the pipes within the initial structure. Typically positioned in central areas, internal drains drain water directly into the sewer. Having internal drains installed comes with many advantageous benefits; they’re applied in convenient positions that ensure water doesn’t begin to pool.

By installing a custom filter, you’ll be able to prevent frequent clogging within the pipes. This way, reoccurring issues with the installation of the internal drain will refrain from happening. You won’t need to worry about gutters or downspouts; however, your roof will need to be cleaned regularly to prevent blockages.



Scuppers are used on railed rooftops. They allow the water to drain off freely; made with simple openings through the perimeter curbs of the walls, scuppers transfer water from the roof into the gutter.

You can extend the scupper to make water flow directly off the building and away from the exterior surface. Roughly four to six inches in height, scuppers aren’t huge openings, but big enough to get rid of water on your flat roof.


Gutters and Downspouts

The most common drainage type, gutters are primarily used across the globe on an array of homes and commercial buildings. Both gutters and downspouts work together to make an effective solution to remove excess water from your roof.

However, gutters and downspouts are commonly known for clogging up and becoming filled with leaves and unwanted debris. It’s important to ensure your gutters are clean; this way, rainwater can drain away easily.


Long-Term Effects of Ponding on a Flat Roof

Without effective drainage, your roof will deteriorate and fail to perform as it should. It’s important to ensure that necessary drainage is put in place whilst your roof structure is being built. Not providing enough drainage comes with a variety of issues that can prove to be costly and time-consuming to fix.

In the worst-case scenario, a new roof will have to be built if your initial structure is heavily damaged. Ponding or standing water is ultimately when the water on your roof collects together and doesn’t drain properly. Typically, if no water can drain efficiently within 48 hours, it’s more than likely that it’ll stay even longer.

If for any reason your flat roof begins to pool but you don’t know why, there are a few vital things you can do. If you’re aware that you have a poor drainage system, then it’s time to consider having new solutions put in place. If you do have drainage, be sure to check for blockages.

Additionally, you can also check the pitching of the roof to see if it’s been applied correctly; weak membranes and caulking issues can be key suspects to flooding. Long-term effects of pooling can cause more leaks, a sagging roof, overall deterioration, moss build-up, algae, plant growth and a weaker membrane, which causes more issues in the long run.


Roofing Solutions at Restec

Here at Restec, we’ve been providing specialist products for numerous years. Our solutions are sold across the market, proving to be strongly favoured by those working within the roofing industry. If you’ve recently been subject to having to deal with a flat roof with poor drainage and pooling issues, it might be time to have effective drainage installed and a fresh waterproof membrane applied.

Our extensive range of liquid waterproof solutions can be found across our site, as well as in various merchant stores up and down the country. Our flagship product, Flexitec 2020, is a multi-surface flexible GRP roofing system that has revolutionised the liquid roofing industry. Another firm favourite, GRPROOF 1010, is used by contractors in a plethora of locations, proving to be the ideal system for flat roof projects.

We understand the difficulties that come with flooded flat roofs; having a reliable, waterproof membrane applied offers longevity and reassurance that your roof is protected. For more information or to speak directly with a member of our team, feel free to contact us here. We look forward to hearing from you soon.

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