Can you add a drainage system after your home is built?

Offering reliable landscaping services to homeowners in British Columbia since 2013

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Natasha Maerz

Owner/Office Manager

Surprisingly, many older homes in the Fraser Valley do not have any type of drainage system in their yards, or around the perimeter of their home.

Because of this, construction may have to be done with the home and landscaping already in place.

When a home is already built it can be a lot harder to add a drainage system due to structures that may already be in place, such as sidewalks, patios, plants, trees and flowers. This can cause the project to double in investment due to having to repair these structures.

So, how hard is it really to add a drainage system after a house is built in the Fraser Valley?

The site and how it is graded

Re-grading a site after finished landscaping has been installed is a big undertaking. Sometimes the entire area may not need to be re-graded,  but any area that is needing. grading will be like starting over. 

The process of re-grading a residential backyard involves stripping, trucking and disposal of the grass, excavating the soil to raise and lower areas as to form a downward slope away from all structures.

Perimeter And Downspout Drains

Adding a perimeter and downspout drain system requires excavating down to the bottom of your foundation, this is often in the range of 2-8 feet deep and 3-4 feet wide.

If you have a sidewalk or patio in place, the concrete or pavers may need to be taken out depending on where the drainage needs to get placed, and once the drainage is put in, will need to be replaced.

Unearthing this area requires the use of an excavator and requires digging all the way around your building. Large piles of soil the size of cars are placed away from the open area so workers in the trench are protected.

Temporarily placing this soil away from your home creates a wide working area that will affect grass, and any plants in the area. Special care can be taken in certain areas such as around decorative concrete, trees, and valuable areas. It’s important to note doing this is a major undertaking, and extensive landscaping will need to take place afterwards.

Any plants or trees that are around the area may need to be completely replaced or removed and replanted. Situated grass can be protected with plywood depending on how large the homeowner’s lot is, but sometimes the grass will need to be replaced with sod, or seeded.

Another thing to keep in mind is that machines need to be able to access the area to dig the trench and bring materials like soil and gravel in and out. If there is a fence panels may need to be taken down depending on how wide to the gate the backyard is.

All in all, it is possible to add a drainage system to a home after a home is built, but adding drainage before construction is finished will be less of an investment due to the remediation that needs to be done on homes that are completely finished.