Oaks Designer Resource Guide (Canada)

WALL CLASSIFICATIONS

FREESTANDING Freestanding walls are vertical architectural features finished on both sides. Typically they are small sitting walls (less than 600mm (2’) high), but they have also been used as divider walls (see page 27) and even security features.

GRAVITY Simple (single depth) Gravity walls depend on the mass of the individual wall units dry- stacked on top of one another to hold back the earth behind the wall. Due to the limited mass, these are typically restricted to low retaining walls.

For batter, alignment and installation options, go to page 52 of the Products section. GEOGRID Geogrid (soil) Reinforced walls include multiple layers of geogrid reinforcement sandwiched between the wall units and extending back into the compacted reinforced soil zone. They are used when the limitations of a conventional Gravity wall are exceeded.

MULTI DEPTH GRAVITY Multi Depth Gravity walls use products of at least two different depths to increase the overall mass of the wall. (Note: there must be a connection between the rows of wall units). See adjacent page for more information.

STABILIZED BACKFILL The Stabilized Backfill system is a unique solution commonly used when lot lines, rock outcroppings or other obstructions limit the amount of excavation that can be done, or to provide enhanced stabilization for fences situated close to the back of the wall. See adjacent page for more information.

CALL BEFORE YOU BUILD – WHAT ARE THE LOCAL RULES FOR RETAINING WALLS? Retaining walls are engineered structures that require a site-specific design prepared by a Professional Engineer certified in the jurisdiction where the wall is being constructed. For example: 1. The Ontario Building Code (OBC) requires a site-specific design for retaining walls exposed over 1m (3’) that are adjacent to; public property; access to a building; private property allowing public access such as a person’s front yard for mail delivery to the front door. 2. Some local municipalities in Ontario have expanded Building Code requirements to include any retaining wall over 1m (3’), including those on private property. 3. The CSLA Canadian Landscape Standards recommends that any wall over 1.2m (4’) or one that may be exposed to heavy or dynamic loading should be designed by a structural engineer. An evaluation of soil conditions by a geotechnical engineer may be required. Check with your local municipality before proceeding with your construction project. Consult with Oaks staff if you require a site-specific design package. (See Page 24 for guidance on how to initiate a site specific design through Oaks) GUARDS: The OBC also requires a guard at the open side of any wall that meets the above requirements, to prevent pedestrians from falling over the edge. Some municipalities have expanded this requirement to include any steps, ramps, exterior landings, porches, balconies, mezzanines, galleries, or raised walkways where: 1. There is a difference in elevation of more than 600mm (2’) between the walking surface and the adjacent surface. 2. The adjacent surface within 1.2m (4’) of the walking surface has a slope greater than 1:2. You will need to incorporate additional design loads into the retaining wall design to compensate for pedestrians pushing against the guards. (See Pages 31 to 34 for more information on pedestrian guards and fences)

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