What is the cost per square foot for complete subfloor replacement in a New Brunswick home built before 1960?

Subfloor replacement in pre-1960 New Brunswick homes typically costs $8-$15 per square foot for complete removal and installation of new plywood or OSB subflooring. This wide range reflects the complexity of working with older construction methods and the structural unknowns common in homes from this era.

Pre-1960 homes in New Brunswick present unique challenges that drive up subfloor replacement costs compared to modern construction. Most homes from this period were built with 1x6 or 1x8 board subflooring laid diagonally over 2x8 or 2x10 floor joists spaced 16-24 inches on center. These board subfloors have often developed gaps, warping, and rot after 60+ years of Maritime humidity cycles, especially in areas near bathrooms, kitchens, and exterior walls where moisture infiltration is common.

The replacement process involves several cost components that add up quickly. Removal of old board subflooring runs $2-$4 per square foot, depending on whether the boards are nailed or screwed and how much they've deteriorated. Many contractors discover additional issues once the old subfloor is removed — floor joist repairs or sistering can add $15-$25 per linear foot for damaged joists, and bridging or blocking installation to meet modern standards adds $3-$5 per square foot. The new subfloor material itself — typically 3/4-inch tongue-and-groove plywood or OSB — costs $2-$4 per square foot, with installation adding another $3-$6 per square foot.

Coastal New Brunswick homes often require additional moisture mitigation during subfloor replacement. Homes in Saint John, Shediac, Bathurst, and other coastal communities frequently show signs of salt air corrosion on metal fasteners and elevated moisture in the floor assembly. This may require upgrading to stainless steel or galvanized fasteners and installing vapor barriers or moisture management systems, adding $1-$3 per square foot to the project cost.

Practical considerations for budgeting include the reality that subfloor replacement often uncovers other issues requiring attention. Knob-and-tube wiring, outdated plumbing, or inadequate insulation discovered during the work can add thousands to the project scope. Plan for 10-20% contingency costs beyond the base subfloor replacement estimate. The work also requires temporary living arrangements since entire rooms become uninhabitable during the 3-7 day replacement process.

This is definitively professional work requiring structural assessment, proper joist evaluation, and knowledge of building code requirements for subfloor attachment and spacing. Attempting DIY subfloor replacement in a pre-1960 home risks compromising the structural integrity of the floor system and creating safety hazards. The specialized tools required — circular saws, reciprocating saws, pneumatic nailers, and pry bars — combined with the physical demands of removing and installing heavy plywood sheets make this a job for experienced contractors.

Get multiple quotes from contractors experienced with heritage home renovation, as pricing can vary 30-40% between contractors familiar with older construction methods versus those who primarily work on modern homes.