Installing French drains can help with these problems. They are a safe and reliable way to move water away from your foundation and out of your yard. If you live in the greater Twin Cities, Landscape Guys can install a French drain that earns its keep.
Parts of a French drain that’s effective at handling water
This type of drain isn’t named after the country, but rather after Henry Flagg French, a American and assistant US Treasury Secretary. In 1859 he published a book about farm drainage, which popularized what came to be known as the French drain.
There are several design variations of French drains, but their core design is a trench that’s lined with fabric and filled with gravel, with a perforated pipe placed near the bottom of the gravel. Water flows easily into the gravel and then seeps into the pipe, which carries it away to a designated discharge area. Sometimes the gravel is covered with permeable tiles, to protect it and add visual interest.
A trench with gravel and a pipe may sound simple, and in many ways it is. But in order to function right, the people who build it need to take many critical factors into account.
Trench size and location. If the trench is too small it won’t catch enough water; too big and it’s unnecessary labor and takes up more space than needed. If located in the wrong place, the drain won’t catch water correctly. If the trench is dug without proper planning, it can destroy underground pipes and cables. Trenches are also a lot of work to dig without professional equipment.
Slope or pitch. The drain needs to be graded with a slope that effectively carries away water. If it’s too flat, water will sit in the drain. It’s the same as with gutters (including underground downspouts).
Pipe size. Most French drain pipes are 4” PVC or similar smooth-bore pipe, but a larger pipe may be required to handle serious water. Corrugated flex tubing is an option in most cases.
Perforation size and location. It’s counterintuitive and a very common mistake, but the holes are supposed to go on the BOTTOM of the drain pipe. If the holes are too small the pipe won’t fill up with water easily and discharge it easily.
Fabric liner. The liner prevents sediment and small particles from entering the drain and clogging the gravel or perforated pipe, while still allowing water to pass through. If the liner’s weave is too tight, it can create a barrier that prevents water from entering the drain. On the other hand, if the liner weave is too loose, it can allow fine soil to enter the drain system and slowly clog it. Cheap liners degrade quickly underground. If the fabric liner does not offer any form of root resistance, tree and plant roots may grow into the drain system in search of water. This can cause blockages and potential damage to the structure of the drain.
Gravel size. Gravel is one of the most important components of a French drain. It needs to be the right size for water to percolate through it reliably, without clogging. Gravel that is too big or too small makes clogs more likely.
Discharge point. The drain needs to bring water somewhere well below grade to be discharged. A badly placed discharge point can lead to erosion, water flowing back toward your home, pooling in new locations on your property, conflict with neighbors, or code violations and fines.
Get your French drain
French drains are great if you’re a homeowner looking to protect your foundations from water damage. A motivated homeowner can install a perfectly functional French drain, but it takes a lot of work and research to do right, and possibly pulling permits (e.g. a trench permit). Some landscapers do very good work installing French drains, while others slap them in and hope you don’t notice any problems until it’s too late to ask for a redo or a refund.
We’ve installed French drains on large and small properties throughout the Twin Cities area. We’ll look at your property, budget, and goals, and help you decide if a French drain is right for your needs, or if you’re better off with a different or additional drainage method. Contact Landscape Guys for a consultation and to take the first step towards a safer, drier home and property.