You should find the correct French drain distance from house to install it effectively. If not, it may damage the basement causing additional issues. French drains function best when installed at a correct distance, at the proper slope, to direct water away from the house. Here’s everything you need to know about installing a French drain around the house.
What is a French Drain?
A French drain appears similar to a drainage ditch which can be easily identified with the exposed end of the pipe with a downward slope. It allows water to pass through it easily without pooling like in normal trenches. A French drain contains a perforated pipe through which water can enter the drain and is also lined with gravel and filter cloths.
How to Find the Right Distance From Home?
To find the correct distance, first, check where surface water pools naturally during heavy rain. It is important to locate the French drains in areas prone to flooding as their task is to carry water away from home. You should also consider the gutters when installing an exterior French drain. Draining too close to the house is also not a good idea as the water might damage the foundation causing long-term structural problems. Install the French drain at the correct distance from the foundation of your house. Do not install the French drain in a straight line from the foundation. It will pool water near the foundation, causing erosion.
How Close to the House Should a French Drain Be?
The best distance to install a French drain is about 3 – 4 feet away from the house. Having the French drain at this distance makes the French drain effective without causing any damage to the house. Measure this distance around the house including the porch and basement and use spray paint to mark where the drain should be. Always direct the water away from your home, starting from a higher elevation. Make sure to have a suitable distance even if you are installing a French drain between houses.
The Process of Installation
- Check for underground utility lines and pipes and find a suitable distance from home.
- Once you measure the distance and mark it precisely, you can start the installation.
- You can dig the trench with a shovel or even use suitable machinery. The recommended depth for a French drain is around 18 – 24 inches.
- Make sure to have a downward slope of 1% for the water to flow well. Flat drains will pool the water and eventually flood causing additional trouble.
- Lay a water-permeable filter fabric over the trench to keep the dirt and tree roots away from the drain.
- Add gravel or landscaping stone along the bottom of the trench. This is the bedding for the drainage piping.
- Install an inlet grate where water collects the most and secure the necessary fittings to extend from this point to the outlet point.
- If you need a curved drain, you can use a flexible drainage hose.
- For a more durable system, you can also use a PVC pipe with holes drilled every 6 inches.
- Lay the pipeline in the trench over the crushed stones and have the holes of the pipe pointed downwards.
- Pour some water into the inlet grate to test the flow of the drain.
- Cover the pipe with gravel but do not cross over the ground level. Wrap excess filter fabric over the stones and another layer.
- Finally, you can fill the trench with topsoil and cover it completely.
When Shouldn’t You Install a French Drain System?
Installing a French drain is not the solution to every drainage problem. They can only remove water away from your home to a spot that will not damage your property. So, it should have the necessary environment to carry the water along a trench. French drains cannot be installed in swampy yards that collect a lot of water. In that case, you can consider a different option such as installing a rain garden or a catch basin.
Frequently Asked Questions
Why Do French Drains Fail?
French drains may become clogged over time as soil and clay granules slip into the trench through landscape fabric. They gradually build up inside the pipe and reduce the ability to drain water. Despite using a filter fabric, roots from shrubs, and trees around can still invade the French drain.
How Much Does It Cost to Put in a French Drain?
Interior French drains are more expensive than exterior drains since they require more labor. Installing an interior French drain includes excavating through a concrete floor. The average cost to install a French drain at home will be between $5,000 and $13,500. Most basements require a French drain of length 100 – 150 feet. An exterior French drain costs about $10 – $50 per linear foot while an internal drain costs $40 – $100 per linear foot.
Which is Better Interior or Exterior French Drain?
Both interior and exterior French drains are effective drainage mechanisms to protect your basement against flooding and water damage. In addition to the difficulty of installing, exterior French drains are hard to service and maintain. Although the installation process of interior drains requires more labor, the maintenance is fairly easier as they do not get interfered with by soil or roots.
Do You Need a Sump Pump if You Have French Drains?
It depends on the amount of water in your basement and surroundings. If there is excess water in the basement, you might have to consider having both a sump pump and a French drain to remove water from your home. The two solutions have different mechanisms for draining out the water. A French drain directs the water to the sump pump pit where it will then pump the water out of the home. This is a much quicker draining method than any of these would do alone.
Can French Drains Be Covered With Grass?
You can use grass to cover the French drain since grass doesn’t require as much water as streamside plants. It will be safe since the roots of grass do not go too deep as to invade the French drain.
Installing a French drain is not a difficult task if you know all the details beforehand including the French drain distance from house. You can install it on your property to drain out the water as necessary to keep your lawn and basement dry. If you are living in a region with frequent rain and storms, this will be a perfect investment for your home. In addition to this, there are several other water discharge options depending on the nature of your land.