Accessory Dwelling Unit (Adu) Foundations
When considering an accessory dwelling unit (ADU) foundation, understanding the different types of solutions is a pivotal aspect.
Two of the most common foundation methods are slab-on-grade foundations and poured foundation walls.
Slab-On-Grade Foundations
Slab-on-grade foundations are comprised of a structural concrete "slab" which also serves as the first floor of the building.
The slab consists typically of a 4"-6" concrete slab with a thickened perimeter with rebar and welded wire mesh designed by an engineer according to building size.
Slab-on-grade foundations are monolithically poured, meaning all the concrete is poured and sets at one time.
Slab foundations are only achievable if the location of the structure is on level ground. Additional site grading may be needed to defer water from the building.
Poured Foundation Walls
Poured foundation walls are concrete walls poured on concrete footings. This is the standard method of foundations in Ontario. It offers the benefit of accommodating existing site grades, allowing for the elevation of the main floor, which helps prevent water and moisture issues.
Solutions That Fit Your Needs
Poured foundation walls for accessory dwelling units give the possibility of 3 types of basement options to best suit your needs.
