Construction Performance Guidelines
CEILING IS UNEVEN
Within a room or space, where an isolated bulge or area of waviness appears in the ceiling and is not a structural problem, the variation shall not be greater than 12mm above or below the specified plane.
One-Year - Work and Materials.
An isolated bulge or area of waviness in the ceiling caused by normal shrinkage of materials due to drying after construction is excluded from the statutory warranty.
An isolated bulge or area of waviness in the ceiling greater than the acceptable performance shall be repaired.
Even when installed according to the Ontario Building Code, it is not unusual to see an isolated bulge or area of waviness in drywalled ceilings due to joint finishing. These conditions may appear more severe at night when artificial lighting washes across the ceiling.
An isolated bulge or area of waviness may also be caused by applying ceiling drywall over major structural components, such as beams, or possibly due to truss uplift. See section 9.5 Ceiling/Wall Joint Separation Commonly Referred to as "Truss Uplift".
To measure this type of variation, refer to appendix A4: Measuring Variation from the Specified Plane using a Plane of Reference.
This Article, as revised, applies to all conciliations after January 1, 2019.
- 9.2 CEILING TEXTURE IS UNEVENLY APPLIED
- 9.3 GYPSUM WALLBOARD CORNERS ARE UNEVEN
- 9.5 CEILING/WALL JOINT SEPARATION COMMONLY REFERRED TO AS “TRUSS UPLIFT”