Use of milled (unstamped) lumber
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 [188.8.131.52(1)] 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.
Development permit structures exempt
In unincorporated areas of New Brunswick, the province allows for accessory buildings to be constructed with nothing more than a Development Permit.
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.
As long as the truss/rafter span is less than 32 feet, and the total usable area is less than 2,100 square feet, these buildings do not have to meet the requirements of the National Building Code, meaning that the lumber used in this construction does not have to be stamped – so milled lumber is acceptable in those structures.
The same development permit structure allows small buildings indented for residential occupancy – tiny homes or camps – to be built with a development permit, as long as the total area is less than 625 square feet. In these cases, these structures can also be constructed with milled lumber, as they do not have to meet Code.
Municipal accessory buildings
The Southwest New Brunswick Service Commission has worked with its municipal partners to streamline building regulations. As a result, the municipalities of Harvey, McAdam, Saint Andrews and St. George now allow small accessory buildings (sheds and garages) of up to 600 square feet to be built as development permit structures that do not have to meet Code. In these situations, these buildings can also be constructed with milled lumber.
Milled lumber in Code-compliant buildings
Despite the restrictions of clause 184.108.40.206(2) 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 220.127.116.11(2) 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.
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.