French drains, trench drains and weeping tiles
Move surface and groundwater away from your home with underground drainage systems.
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Who should take action
- Homeowners
- Landlords and property managers
- All homes with:
- basements, especially chronically damp basements
- poor exterior drainage, such as ground sloped toward the home
What it is
French drains
A French drain is a gravel-filled trench with a buried, porous pipe to drain water in your yard away from your home.
- The pipe is called a weeping pipe
- Holes allow water to flow in and out of the pipe, or 'weep'
- The pipe is typically covered by filter fabric to keep out debris
- Mainly used to manage surface water, but can also help manage groundwater
- Drains safely away from your foundation and ensures soil isn't constantly saturated
- Installed anywhere on the property just below the ground's surface
Trench drains
Also known as channel drains, these are narrow metal or plastic troughs fitted with grates to collect runoff from paved areas on your property.
- Installed near or on patios, walkways and driveways to collect and redirect excess surface water
Weeping tiles
Also known as weepers, drain tiles, perimeter drains, and foundation drains, these systems collect groundwater using a weeping pipe and direct it away from your home's foundation. The water may drain to your sump pump or directly to the municipal storm sewer system.
- Installed deep underground at the base of a home's foundation for groundwater drainage
- Reduces the water pressure pressing against your foundation
- Almost all newer homes (e.g., homes built in the last 50 years) have a weeping tile system
- If you're not sure whether you have one, consult a professional
- The presence of a sump pump or buried downspouts can indicate you have a weeping tile system
- Even if your home has a weeping tile system, it may not be operational since these systems can become clogged with soil over time
Benefits
Installing or upgrading drainage systems is a high impact action that can help prevent flooding of your home and property and save you money over the long term.
Heavy rain, snowmelt and groundwater can seep into your home's foundation, basement or crawlspace. Rising groundwater can also create pressure against the foundation, potentially causing structural damage.
While a correctly graded property is your first line of defence, these additional drainage measures can help:
- Protect your home's foundation, basement, and crawlspace
- Avoid erosion, waterlogging, and water pooling on your property
- This helps maintain the usability, health and aesthetics of your garden, patio, and other landscaping features
- Reduce the risk of leaks, cracks, and mould in your home
What's involved
Check with your local government about regulations such as permits or inspections required before installation.
Consult a professional before taking any of these actions to ensure they're right for your home, and to help with installation as needed.
French drains
- A professional can install these drains anytime the ground is not frozen
- Trenches are typically installed 20 to 30 cm (8 to 12 in.) below ground, and can be dug out manually or by using a trencher
- The weeping pipe will be placed in the trench along with gravel, dirt, and a waterproof filter fabric
- Installed with a slope to drain from a higher point to a lower point
Trench drains
- A professional will cut through any existing concrete or asphalt before creating the trench
- The excavation depth depends on the drain model and the existing property grading
- The trench grate or cover must be kept clear of debris for continued drainage
Weeping tiles
- A professional will install weeping tiles at the foot of your foundation
- Install at a depth of 1.8 to 2.5 m (6 to 8 ft.) below ground level
- Installing weeping tiles will require the use of excavation which typically includes the use of heavy machinery
- The weeping tile will be placed in a trench along with gravel around the perimeter of your home
- Weeping tiles are usually connected to the municipal storm sewer system by your property's storm lateral (pipe). When weeping tiles can't properly drain to the storm lateral with gravity drainage, you may have to install a sump pump in conjunction with your weepers
- If the foundation is not waterproofed or requires repairs, the professional may do so during weeping tile installation as the foundation is exposed
- They can also be installed inside the home, beneath the basement floor. However, managing water outside the home is most effective and may provide longer-term solutions
When to take action
French and trench drains
- If you can't achieve a desirable grade on your property, French and trench drains can improve drainage
- Driveways that slope down toward the home (reverse slope driveways) often benefit from trench drains as they help prevent water from pooling at the bottom of the driveway that could enter your garage or basement. It's important to note that trench drains will not prevent flood risks from severe rainfall
Weeping tiles
- Homes with damp basements or a history of basement flooding may benefit from replacing or installing weeping tiles
- Many homes are built with drainage systems, but changes may be needed. This depends on the age of your home and your property grading
Consider adding new drainage systems to your property if you are experiencing the following issues:
- Signs of drainage problems outside your home
- Pooling water on your driveway, patio or yard after rainfall or snowmelt
- Persistently soggy spots on your yard that limit plant growth
- Erosion of soil and plants in your yard
- Cracks in your foundation
- Signs of drainage problems inside your home
- Damp and musty smelling basements
- Cracks in your foundation, basement floor and walls
- Water leaks into the basement during heavy rainfall
- Mould and mildew in your basement
Be flood ready
Flood readiness requires regular upkeep just like any other home or property maintenance task. Make maintaining your drainage systems part of your maintenance checklists.
Seek support from a local professional, friend, family or neighbour if you're unable to complete this task on your own.
Related links
Other property drainage systems include: