The Best Drainage Solutions for Flat Roofs

Flat roofs offer a unique look for buildings and are used frequently in commercial construction. While they’re popular in commercial buildings, recent designs have led to an increase in flat roofs at residential homes. They have a number of benefits and are a great fit for simple, modern looks. In fact, flat roofs are more resistant to persistent environmental climates and can be used to increase your livable space. If you want to get the most out of a flat roof design, you can turn it into a unique, private living space!

Keeping Gutters and Drains Clean

The challenge comes with heavy rain, snow, sleet, and hail. It pounds down on all roofs, flat and slanted, but if you have a flat roof, it has nowhere to go. That’s why having a strong drainage solution in place is so important. When you don’t utilize the proper drainage solutions, water will quickly pool on your roof and put unnecessary stress on your building’s foundational support. This is because flat roofs, not surprisingly, lack the gravitational drainage help that slanted roofs have.

Over time, continual pooling water leads to annoying leaks, overall structural damage, a persistent accumulation of debris, costly deterioration, and eventually, necessary roof replacements. It’s easy to protect your roof from these problems, as long as you don’t wait until it’s too late. Instead, make sure you have an effective drainage solution in place today. Luckily, after reading about the best drainage solutions for flat roofs, you’ll be all set to ensure your roof is ready to brave the elements.


Most roofs, both flat and slanted, come equipped with a gutter system. It’s the most popular drainage system for the average roof. While one goal of gutters is to drain the water out and away from your home’s foundation for structural protection, they mainly work as a great solution for home’s or commercial buildings with flat roofs. Gutters collect the water that naturally falls off of your roof into open piping systems and leads the water off and away from your home or building. They’re by far the most cost effective drainage solution, but gutters do need to be regularly cleaned and maintained for the best results.

Since they’re easy to install and can be attached to most roofing systems, both finished or not, a majority of home and building owners opt to install gutters over other systems. As long as you take care of them and regularly maintain your gutters throughout the year, you’ll reap the benefit of an effective drainage system for cheap. The only problem with flat roofs and gutters is that there is no gravitational pull for the water that lands in the center of the roof to be directed to the gutter system. There are ways to combat this, but they can get costly.

Remember, one of the easiest ways to ensure that your gutters stay clean and clear of any debris is to avoid allowing trees or bushes to hang over the top of your roof. If this is problematic, you’ll find yourself on a ladder cleaning out your gutters frequently throughout the year.

Interior Drains

Another type of drainage system that works extremely well is an interior drainage system. This works by placing drains across intervals near the middle of the roof that lead first inside then out through a series of gutters and pipes. The internal network is efficient at reducing the amount of pooling water that often accumulates near the center of the roof where most of the water collects on large, flat roofs. To prevent any debris from getting trapped inside, interior drainage systems are equipped with strainers. If you get this type of drainage system, you need to ensure that the strainers are working properly and nothing is getting through. Cleaning exterior gutters is time consuming, but easy when compared to cleaning interior drains. Luckily, this is effortlessly avoided if your strainers are in place and doing their job.

The best part about interior drains is the fact that they’re hidden from the outside view of your building. This creates a seamless aesthetically pleasing look that’s perfect for both homes and commercial buildings alike. The problem with interior drain systems is what happens when damage occurs. While they’re stronger and more protected, since they’re inside a building, if anything does happen, you’ll need to call a professional to come get things fixed.

If you’re interested in installing an interior drainage system for your building, just make sure you contact a professional to get an accurate estimate. Interior drains tend to be more expensive than other types of drainage systems, especially simple gutters. However, if you’re prepared to commit to an upfront investment, it’ll be well worth your while.


Another option for your flat roof’s drainage system is to install scuppers. Scuppers are similar to gutters in that they’re installed on the edge of your roof; however, the way they work is a bit different. Unlike gutters, which collect water and lead it out through a downspout, scuppers work to primarily expel water out and away from the roof. They’re smaller and don’t line the entire edging of your roof. They’re a bit longer and more strongly angled downwards so that gravity helps to push the water off of your roof with the momentum needed to keep walls and siding dry. This momentum also ensures that the foundation of your building isn’t exposed to excess amounts of water.

To get the most out of scuppers, it’s advised to pair them with a roofing system that helps to direct pooled water on flat roofs to them. This is best done using a tapered insulation system. It’s also possible to achieve the direction you need using a sloped structure, but that can add a lot of excess to your roof.

The only downside to using scuppers in the Midwest is snowfall. They aren’t very efficient in managing melting snow and ice and can be damaged if the weather is too severe. Otherwise, scuppers are one of the best options for flat roofs.

True Sloped Insulation

There is also the option to install true sloped insulation. The problem with this type of drainage system is the cost—it’s by far the most expensive option. If you already have a building with a flat roof, it’s not really worth it to install a true sloped insulation. However, if you’re building a new place of business or home and still want a flat roof, this is a viable option. True sloped insulation is installed underneath a roof and works to create a flat roof that utilizes gravity to expel water. The small slope that’s installed acts as a ramp to avoid any excessive pooling and to guide the water off of the surface.

Step Sloped Insulation

If you like the idea of true sloped insulation, but don’t want to spend thousands of dollars, you can opt for a step sloped insulation. The idea is the same: add a slight slant to your roof to get water off and away. However, step sloped insulation uses flat board insulation instead of the roof-board that true sloped uses. This is more cost effective because of how it’s installed.

If you’re interested in either insulation option, it’s advised that you contact a professional roofing company to come out for an inspection. Only the professionals will be able to give you the advice you need based on your roof’s specific parameters.

Calling in the Professionals

Regardless of the type of drainage system you decide to use for your flat roof, you’re best off calling in a professional for a professional opinion. A professional roofing contractor will be able to inspect your roof and give you a recommendation on what type of drainage is best for your roof—at home or on a commercial building. Just make sure you call a professional roofing company with experience, like Advocate Construction. When you decide to use a professional rather than attempting to do it yourself, you’ll save both time and money. Plus, you’ll rest easy knowing that the job was done right, the first time around. Advocate Construction professionals have a level of experience and expertise that only comes with years of hard work, persistence, and dedication. Hiring a professional contractor for all of your roofing drainage solutions will give you peace of mind and can help you avoid disastrous problems down the line.

If you’re on the market for highly skilled professionals then look no further than Advocate Construction. We’re a team of experienced contractors that work efficiently with every budget. All of the jobs are done with high levels of integrity, transparency, and with longevity in mind.

To contact an experienced team of specialists today, give us a call at (414) 386-3900. You can also reach out to our customer service hotline, 833-409-ROOF (7663) or visit us at