Replacing a single rotted stud in an Ottawa wall myself?

A single rotted stud is a structural repair, so the 2024 Ontario Building Code rules for framing apply, and the same permit and Code obligations apply whether you do the work yourself or hire someone.

Before you touch anything, check whether the stud is load-bearing. A stud in a load-bearing wall carries load from above; one in a partition wall does not. The repair approach differs, and if the wall is load-bearing, the floor, ceiling or roof above needs temporary support while the stud is out. How that support is set up is something to work out with a carpenter or designer before you start, not during.

The rot itself tells you something important. If it is confined to one stud, the cause may be a one-time water event that has since been fixed. If the plate, sheathing or adjacent framing is also soft, the repair is larger than one stud. Probe the top and bottom plates and the subfloor around the base of the stud before you plan the scope.

The 2024 Ontario Building Code (O. Reg. 163/24) covers how framing members are sized and connected, but we found no clause in Part 9 that specifies exactly how much rot must be removed or how a replacement stud is fastened into existing plates. Ask your carpenter how the repair is designed and whether a designer needs to be involved, particularly if the wall is load-bearing.

A few things worth checking before you proceed:

• If the house was built before 1960, Health Canada notes it probably contains lead-based paint; paint from any era may contain lead in smaller amounts. Do not sand or heat old paint. Test before you disturb the wall surface.
• If there is old plaster or putty around the area, Health Canada lists those as materials that may contain asbestos. Have them tested before you open the wall.
• The City of Ottawa lists structural repairs as permit work. Confirm with Building Code Services whether this repair requires a permit before work starts.

If you bring in a carpenter instead, ask who is responsible for the permit if one is required.

The most useful question to put to a carpenter before agreeing to anything: once the wall is open, how will you determine whether the damage goes beyond this one stud, and what happens to the price if it does?