How much does it cost to rip out old subfloor and start fresh in a Calgary renovation?

A complete subfloor tearout and replacement in Calgary runs approximately $6 to $12 per square foot total, including demolition, disposal, joist inspection and repair, and new subfloor installation — putting a typical full-home project (1,200 to 1,800 square feet) in the $7,200 to $21,600 range. The wide range reflects the enormous variability in what installers find once the old subfloor comes up — clean joists in good condition on the low end, and rot, mould, structural damage, or asbestos on the high end.

Demolition and removal of the existing subfloor costs $1 to $3 per square foot for labour, depending on the material and how it was fastened. Screwed-down plywood is the easiest to remove. Nailed-down plywood or OSB takes longer. Subfloors that have been glued and nailed (common in newer Calgary homes) are the most labour-intensive to tear out. If the existing subfloor has multiple layers — for example, an original plank subfloor with a plywood overlay added later — demolition costs increase. Old vinyl tile or adhesive on the subfloor surface may contain asbestos in homes built before 1985, which requires professional abatement before demolition can proceed ($8 to $15 per square foot for asbestos removal in Calgary).

Disposal costs in Calgary include bin rental and dump fees. A 12 to 20 cubic yard bin (appropriate for a full-home subfloor tearout) runs $350 to $700 in Calgary depending on size and the waste company. Subfloor material, old underlayment, and demolished finish flooring add up to significant volume and weight.

Joist inspection and repair is the critical step between tearout and reinstallation. Once the old subfloor is removed, you can see the full condition of the joists. In older Calgary neighbourhoods — Bankview, Bridgeland, Crescent Heights, Brentwood, homes from the 1940s through 1960s — joists may show signs of moisture damage, insect damage, notching for plumbing that has weakened them, or general deterioration. Sistering damaged joists (bolting a new joist alongside the damaged one) runs $100 to $300 per joist. Replacing severely damaged joists or adding additional support is more involved and may require a building permit and structural engineering input ($500 to $1,500 for an engineer's assessment).

New subfloor installation using 3/4-inch tongue-and-groove plywood costs $3 to $5 per square foot for materials and labour. This includes fitting the panels, screwing them to the joists at proper spacing, and ensuring the finished surface is flat within the tolerances required for your chosen flooring. Adding construction adhesive between the joists and the new plywood panels (about $0.20 per square foot extra) prevents future squeaking — highly recommended given Calgary's seasonal wood movement.

A realistic budget for common scenarios. A 1,000-square-foot main floor in a 1960s Calgary bungalow with original plywood subfloor in fair condition, no asbestos, and joists needing minor repairs: tearout $1,500 to $2,500, disposal $400 to $600, joist repair $500 to $1,500, new plywood $3,000 to $5,000, total $5,400 to $9,600. Add 10 to 15% contingency for surprises. The same project in a newer home (1990s or later) with clean conditions could come in closer to $5,000 to $7,000.

This is professional work — subfloor tearout and replacement involves structural assessment, proper fastening, and achieving the flatness tolerances that your finished flooring requires. Get matched with experienced flooring professionals through Calgary Floor Installers for a free assessment and accurate quote on your renovation.

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

• Bracha Concrete & Coatings Inc.
• BOND CONTRACTING & CONSTRUCTION INC
• Mike’s Restoration Service
• Alpine Exteriors siding and roofing
• Universal Slate International Inc.