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Use of milled (unstamped) lumber

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Note: changed May 7, 2021, to reflect revisions to provincial regulation (2021-02).

In our part of New Brunswick, portable saw mills have produced quality materials for decades. But use of milled lumber in Code-compliant construction runs into the challenge presented by a clause in the Code [] that requires structural lumber to be identified by a grade stamp. Despite this conflict, it is possible to use milled lumber, in some cases quite easily, and in some cases, depending on where you live and what you want to build.

Small camps, accessory structures exempt

In unincorporated areas of New Brunswick, the province allows for accessory buildings and small dwellings of 604 square feet or less, to be constructed without having to meet Code.
An accessory building is something like a barn, storage shed, greenhouse, or storage garages) that are not used for any occupancy – that is, they are not used for business or commercial purposes that isn’t related to the land use, like an auto repair facility or coffee shop.

Structures that are 2,100 square feet or greater in total floor area or with a truss span greater than 32 feet cannot be considered accessory buildings, and must meet the National Building Code of Canada, which is what requires stamped lumber.

Milled lumber in Code-compliant buildings

Despite the restrictions of clause demanding use of stamped lumber in Code-compliant construction, it is possible to use milled lumber in buildings that must meet Code. (This means all construction or renovation of buildings subject to a building permit.)

Have the lumber graded

Part of the challenge with milled lumber is that it is not stamped as having been graded for use in Code-compliant construction. However, the key requirement of the Code is that the lumber has been visually graded (as noted by clause of the Code) by an individual qualified and licensed to grade lumber. Those wishing to use milled lumber for a Code-compliant building have the option of hiring a grader to grade the lumber. In this case, any lumber that is not suitable will be marked as defective – usually, this means identifying structural defects such as large knots and so on. Our office will accept a document outlining that the lumber has been graded as an acceptable alternative to using factory-stamped (graded) material.

Engineer approval

The other alternative is to have material certified as structurally suitable for the intended task by a certified structural engineer qualified to work in the province of New Brunswick. This is usually used in situations where classic rough-hewn or open timber post-and-beam construction is desired.


Many older homes in the region were built with milled lumber, with true 2x4 studs. In situations where renovations are taking place, it is inconvenient and troublesome to shim out a nominal 2x4 (1 1/2” x 3 1/2”). In situations where walls are non load-bearing, we have no issue with use of milled lumber as part of renovations of existing milled-lumber structures under our jurisdiction.

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