| If you’re a homeowner suffering from drainage issues, you may have already encountered the option of installing a French drain. French drains are a great option to help manage water drainage issues for homeowners. At Isbir Construction & Landscape Corp., we specialize in EXTERIOR French drain installation services for Pittsburgh homeowners. Let’s look at some of the different types of exterior French drains. |
Hi my name is Mike Isbir and I’m the owner of Isbir construction and landscape located in Elizabeth Pennsylvania just south of Pittsburgh.
Our company specializes in exterior drainage solutions. Our goal is to keep water from getting into your house, building or foundation rather than pumping it out once it is in. So today we’re going to talk about groundwater and exterior French drains.
Groundwater is water that is not visible from the surface of the ground that runs under our feet in between the layers of soil and moves fairly slowly. Groundwater is often referred to as a high water table, a natural spring, or a wet weather spring. Groundwater is typically controlled by collecting it in an underground French drain. French drains consist of a column of gravel with a perforated pipe at the bottom to remove the water from the column of gravel.
There are two basic types of Exterior French drains. Let’s take a look at each one:
The first type of French drain that most people think about when they hear the term “French drain”, is what we call a deep foundation French drain. This typically means that there is a column of gravel from below the building’s basement to the top of the foundation which in round numbers is typically 8 or 10 feet deep.
A Deep Foundation French Drain involves a tar or other waterproofing membrane that is applied to the foundation to permanently seal the foundation so that no water can penetrate it. Then there is a perforated pipe below the basement floor at the bottom of the column of gravel. The system is designed to prevent water from getting into a building or home by sealing the foundation at the bottom to provide an outlet for the water to escape into the French drain and out from around the foundation
The second type of French drain that most people aren’t as aware of is a shallow French drain. This is a French drain that is typically installed in the middle of a lawn or other landscaped area to keep that area dry if it’s plagued by a natural spring or persistent groundwater. You can also use a shallow French drain to collect water so that it doesn’t ever make its way toward your home or building’s foundation in the first place. Shallow French drains are typically 12 to 24 inches deep and on average about 16 inches wide.
Shallow French drains most of the time are 20 feet or more away from the building. We will often grade the ground so that it gradually slopes towards these shallow French drains to allow them to collect water quicker from a swampy or low-lying area.
With the shallow French drain we often choose leave a decorative river gravel exposed at the surface of the French drain to allow excess surface water to get into the French drain in addition to collecting any unwanted groundwater.
I should also be clear that the exposed gravel on a shallow French drain is designed for residual surface water only and not for high volumes of fast-moving surface water. High volumes of surface water would require a specific surface water drainage solution, not a ground water solution. if you have more questions on this please watch our video about surface water or check out our blog for more drainage related tips!
To sum it all up, external French drains come in two types: deep around the foundation, and shallow at a lawn or landscape area. It is important to use the correct one for your specific groundwater problem. Isbir construction proudly provides both as well as a comprehensive suite of drainage solutions and leverages civil engineering degrees, experienced staff and excellent customer service practices to keep Pittsburgh yards and basements dry.
For more information please call 412-751-4539 or fill out a form on our website to get started on your French drain project!
Watch our latest videos on a variety of subjects from groundwater to drainage! Gain new knowledge and insight on the topics that impact you.