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These companies serve Saint-Constant from nearby bases in towns including Montreal, Laval and Sainte-Catherine.
24 companies listed · 6 open 24/7 · 19 open weekends · 21 rated 4.5+ · 5 show a licence
Data verified October 18, 2026
Listed for homeowners in and around Saint-Constant, QC, these 24 companies test for mould and indoor air problems. Listings show what each one states about sampling, lab work and the environmental tests it offers, plus ratings and quotes from public reviews.
The 24 companies on this page are rated from 4.2 to 5.0 across 3,401 reviews; 16 have 50 or more reviews and 21 are rated 4.5 or higher. When customers rate these companies on specific qualities, they most often praise professionalism (95%), quality (73%) and responsiveness (64%). The topics that come up most in reviews of the companies on this page are "efficient", "price" and "informative". 6 are open around the clock and 19 are open on weekends. 5 show a licence on their websites and 1 lists staff certifications (ASHI and InterNACHI). Domain records put 10 websites of the companies on this page at ten or more years old; the oldest dates from 2003. 6 offer emergency call-outs; 1 offers financing or payment plans; 1 gives free estimates and 1 lists coupons or special offers. We have a website on file for all 24 of the companies on this page; 16 publish a contact page; 13 list a public email and 2 take bookings online. We count these figures across the companies on this page; hours and prices change, so confirm the details with the company before you book.
Not when the first visit ends with a large removal quote attached. You have 24 companies on this page, so getting a second diagnosis is straightforward. Ask each one what it thinks the water source is. Two independent answers that match is the strongest signal you will get.
