Budget for mold cleanup after a flooded Calgary basement?

Mould remediation in a flooded Calgary basement typically runs $1,800 to $6,000 for a medium-affected area (roughly 30 to 50 square feet of wall), and $3,000 to $15,000 or more if the damage covers a whole basement. Where your job falls depends on a few things worth understanding before you accept a quote.

The main cost drivers are how far the water spread and what materials got wet. Alberta's OHS bulletin notes mould can begin growing within 24 to 48 hours on a damp surface, so timing matters. Porous materials, drywall, carpet and ceiling tiles, typically require removal rather than cleaning, according to Alberta Health Services. That adds disposal and replacement costs. If the basement has a drop ceiling or vinyl flooring and your home was built before 1990, the Alberta OHS Code's asbestos provisions come into play before any cutting or pulling starts: the Alberta Asbestos Abatement Manual lists ceiling tiles and vinyl sheet flooring among materials that may contain asbestos in pre-1990 construction, and those need bulk sample testing before disturbance. Lab testing runs $65 to $145 per sample, with package pricing available for multiple samples.

On the mould side, Health Canada uses three size bands. Small is one to three patches each under one square metre; a healthy person can clean that with water and dish detergent, safety glasses, a disposable N95 respirator and household gloves. If the flood left more than a few small patches, you are in the medium or extensive bands, where CMHC says medium work is for qualified and trained maintenance staff, and large or extensive work calls for qualified and trained mould remediation contractors. There is no Alberta licence or notification requirement specific to mould remediation, and no City of Calgary permit for this work. Alberta Health Services advises against paying for air testing when mould is visible; it is usually not recommended and adds cost without changing what needs to happen.

A fair quote for a flooded basement should cover:

• Moisture readings and a written scope of work before anything is removed
• Containment of the work area and controlled drying
• Physical removal of affected porous materials, not just surface treatment
• Disposal of debris (the City has no specific rule for mould waste; ask the contractor how they will handle it)
• A post-remediation inspection, and whether an independent air quality test is included or quoted separately at $200 to $800

Ask whether the contractor carries liability insurance and has a WCB account in good standing; you can request a WCB clearance letter online to confirm. If any payment is made before the job is finished, the contractor is a prepaid contracting business and must be licensed with Service Alberta; a prepaid contract of $200 or more must be in writing with itemized prices, a completion date and your cancellation rights spelled out.

Once the job is done, keep the written scope, the contract and any report from the post-remediation check together.