TARION: Don’t let Your Landscaping Plans Dampen Your Spirits or Your Basement
By Lucas on Jun 28, 2013
By Tarion:
Summer is here and with all the time spent enjoying the great outdoors, you might find yourself thinking about how to make your yard as beautiful as your new home. Before you dig in, there are a few things you should consider when planning landscaping or building additional structures around your house.
When constructing your new home, the builder has taken care to ensure that water will not accumulate at or near the foundation. Any landscaping that alters this grade could lead to poor surface drainage, ponding, flooding, basement dampness, or foundation settlement – all of which could result in damage that may not be covered by your new home warranty.
When planning to add flower beds, a pool, a deck, a second driveway, or any new structure around your home, take care not to alter your property’s drainage patterns. The Ontario Building Code requires that a building should be located or graded so that water will not accumulate at or near the building or adversely affect adjacent properties and that exterior foundation walls should be extended a minimum of 150 mm above the finished ground level.
Lot grading requirements vary from municipality to municipality, so before making changes to what your builder has put in place, check with your local building department to understand the requirements that apply to your home. In general, the following guidelines should be followed:
The top of your foundation should be above grade a minimum of 150 mm for masonry cladding and 200 mm for wood cladding.
Grade the lot so that the land slopes away from your house for at least 1.8 metres around the foundation.
Do not change the elevation around the lot perimeter.
Extend downspouts so water flows away from the house and does not collect next to the basement walls and windows. No matter how much the elbow joint of the downward drain spout disrupts your flower beds, don’t take it off or water will drain from the roof straight down into your foundation.
Ensure surface drainage is directed away from window wells and exterior stairwells.
Swales (depressions in grading between tract properties that are intended to manage water run-off) should be located within the limits of the lot and have a maximum depth of 150 mm and a side slope of 3 to 1.
Don’t cover up weeping holes (small openings located near the base of masonry structures). These allow water inside a building to move outside and evaporate. Raising the grade above weeping holes could not only allow water to back up and weaken your foundation, but may also allow insects and small animals to enter the building.
Understanding this information before you start landscaping will save you time, money, and frustration. It may also help keep your basement dry and your warranty in place.
If you have any questions about how grading or drainage issues could affect your warranty, call Tarion at 1-877-9TARION or find us on Facebook.
