Should hardwood floors be nail-down or floating in a Maritime climate home?

Both nail-down and floating installations can perform well in a Maritime climate home, but the right method depends on your subfloor type, product choice, and specific NB conditions. Nail-down is the gold standard for solid hardwood over wood subfloors, while floating is often the better approach for engineered hardwood — especially in homes where moisture management is a concern.

Nail-down installation mechanically fastens each plank to the wood subfloor using a pneumatic flooring nailer. This creates an extremely solid, rigid floor with no hollow sound underfoot and no movement between planks. For solid hardwood on a plywood or OSB subfloor above grade, nail-down is the preferred method across the industry and the one most NB installers recommend. The fasteners hold each board firmly in place, which helps manage the expansion and contraction forces that NB's 30-50% annual humidity swing creates. Nail-down requires a minimum 3/4-inch plywood or OSB subfloor — if your NB home has the older board-style subfloor common in pre-1970s construction, a 3/8-inch or 1/2-inch plywood overlay ($1.50-$3.00/sq ft) should be installed first to create a stable nailing surface.

Floating installation uses a click-lock or tongue-and-groove system where planks connect to each other but are not attached to the subfloor. The entire floor assembly sits on an underlayment and moves as a unit with humidity changes. This method works with engineered hardwood and is the only option for installation over concrete, which rules out nail-down. Floating is also the preferred method over radiant heat systems because it allows the floor to expand and contract freely without the constraint of fasteners.

For NB's Maritime climate, here is how to decide:

Choose nail-down when you are installing solid hardwood on a wood subfloor above grade, you have proper humidity control (humidifier in winter, dehumidifier or AC in summer), and you want the most solid feel underfoot. This is the traditional approach and it performs excellently in NB when humidity is maintained at 35-55% RH.

Choose floating when you are installing engineered hardwood over concrete, over radiant heat, or in a situation where moisture from below is a concern (ground-level slab, basement perimeter). Floating installations also make sense in rental properties or situations where you may want to remove the floor later. Always use an underlayment with an integrated vapour barrier when floating over concrete in NB — Maritime moisture vapour transmission through concrete is continuous.

Glue-down is the third option, most commonly used for engineered hardwood directly over concrete. A full-spread adhesive bonds the planks to the slab, creating a very solid floor with excellent sound performance. Glue-down is more labour-intensive and expensive ($1-$2/sq ft more than floating) but produces a premium result. It works well in NB when combined with proper concrete moisture testing.

Installation labour in New Brunswick runs $3-$6 per square foot for nail-down and $2-$5 per square foot for floating or glue-down. Regardless of method, proper expansion gaps (8-12mm at all walls and fixed objects) are essential in NB — our humidity swings make undersized gaps a recipe for buckling during summer expansion.

Hardwood installation of any type is a professional job. The tools, technique, and moisture management knowledge required are beyond typical DIY scope. Get matched with a qualified flooring installer for a free estimate through New Brunswick Flooring.

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Looking for experienced contractors? The New Brunswick Construction Network connects homeowners with qualified professionals:

• M&L Commercial and residential services
• Gionetterenovations
• First united design & construction inc.
• 3Tone Construction Ltd
• FRS Flooring Solutions