Interior vs. Exterior Drainage Systems

Interior Systems

Drainage systems that are installed along the inside perimeter of your basement floor are called interior drainage systems. These keep your basement dry and safe from flooding or leaks in your foundation walls due to ground or surface water intrusion. They’re much easier and less invasive to install, taking about 1-2 days with no exterior excavation necessary.

Yellowstone Structural Solutions carries several types of interior drainage systems so we can find the right solution for your home’s specific needs. Whether you need a drain that won’t clog, discharge lines that won’t freeze, or a drain system that works with monolithic foundations, we have you covered.

Exterior Systems

Exterior drainage systems are installed around the outside of your home’s foundation. When heavy rains or standing water cause pooling around foundation walls, the pipe collects the water into a gravel-filled trench and carries it away from your home. 

The problem with exterior systems is that they require intrusive excavation around your home. This can include removing gardens, steps, and even porches, making it a more costly option. Plus, exterior drains are prone to clogging, freezing, and inadequate drainage. When a perimeter system fails, the only solution is to dig it up again and repair it. In addition to this, most properties lack the appropriate slope for a basement depth pipe to be able to drain to the exterior via gravity resulting in the need to bring the water back into the basement to be collected and pumped out via a sump pump. At Yellowstone, we always recommend our interior drainage systems as a superior solution.

Which System is Best?

The type of drainage system that your basement needs depends on a lot of different factors. It’s best to schedule a free consultation with one of our foundation experts so we can inspect your home, understand the potential problems that your foundation is prone to, and determine which system is the right fit for your home.

refurbished crawl space

Our Interior Drainage Solutions


The TrenchDrain Pipe System is uniquely designed with a grated opening to span doorways, hatchway entrances, and garage doors to collect flooding water and redirect it to your sump pump.

trench drain in foundation
thin floor basement drain


FlowGuard is an ideal option for concrete slab floors that are very thin. These can be installed in front of the foundation footing instead of on top of it, so it fits under the floor slab easily.


Award-winning patented below-floor drain that’s most popular with homeowners. The WaterGuard System has an anti-clog design and collects water from leaking foundation walls.

waterguard in foundation


DryTrak is a customized drainpipe system for homes with monolithic or thick concrete floors. They require zero jackhammering to install and collect water from foundation walls and floor joints.