What red flags should I watch for when hiring a spray foam contractor in Saint John?

Hiring a spray foam contractor in Saint John requires more due diligence than almost any other home improvement trade — a bad spray foam job is expensive to fix, potentially impossible to reverse, and can leave your home smelling like chemicals for months or worse.

Spray foam is one of the few insulation products where a poor installation is genuinely worse than no insulation at all. Here is what to watch for before you sign anything.

Red Flags Before the Job Starts

No proof of liability insurance or WorkSafeNB coverage is the first thing to check. Spray foam involves hazardous chemicals (isocyanates) that require proper handling, respiratory protection, and disposal. Any contractor who hesitates to provide a current certificate of insurance should be removed from your list immediately. Ask specifically for general liability coverage (minimum $2 million for residential work) and confirm WorkSafeNB coverage for their crew.

Unusually low quotes are a serious warning sign in the spray foam trade. If one contractor quotes $2.50 per square foot for closed-cell foam while two others are quoting $4.50-$6.00, the low bidder is almost certainly cutting corners — using off-ratio material, under-applying thickness, using a lower-quality foam system, or skipping proper surface preparation. Spray foam is not a commodity where the cheapest price wins. The material cost alone is significant, and proper equipment (heated, proportioned spray rigs) is expensive to maintain.

Vague or verbal-only quotes with no written breakdown of foam type (open-cell vs. closed-cell), installed thickness, and R-value targets are a red flag. A professional contractor will specify exactly what product they are installing, at what thickness, and what R-value you will achieve. If they cannot or will not put this in writing, walk away.

No questions about your existing assembly is another warning sign. A knowledgeable spray foam contractor will ask about your vapour barrier situation, existing insulation, ventilation, and what the space is used for before quoting. A contractor who just measures the square footage and gives you a number without understanding the building assembly does not understand building science well enough to be trusted with spray foam.

Red Flags During and After the Job

Persistent chemical odour lasting more than 72 hours after application is a serious indicator of off-ratio foam — meaning the two components (A-side isocyanate and B-side polyol) were not mixed at the correct ratio. Off-ratio foam does not cure properly, can remain chemically active, and has caused homeowners to be displaced from their homes for weeks or months. Properly installed spray foam should be odour-free within 24-48 hours of application.

Visible shrinkage, cracking, or pulling away from framing within weeks of installation means the foam was applied incorrectly — wrong temperature, wrong mixing ratio, or applied too thick in a single pass. Closed-cell foam must be applied in lifts no thicker than 2 inches at a time to prevent exothermic heat buildup during curing. A contractor who applies 4-5 inches in a single pass is taking a shortcut that causes cracking and delamination.

Uneven texture, fisheyes, or a bubbly surface on the cured foam suggests temperature or humidity problems during application. Spray foam cannot be applied to surfaces below 15 degrees Celsius or in high-humidity conditions without special equipment and materials. Saint John's coastal climate and damp basements make this particularly relevant — a contractor who sprays your cold rim joists in January without properly heating the substrate is gambling with your money.

No cleanup or overspray protection before the job starts is a sign of an inexperienced crew. Spray foam overspray is nearly impossible to remove from windows, electrical panels, pipes, and finished surfaces. Professional crews mask everything that should not be foamed before the guns start.

Questions to Ask Every Contractor

Ask what foam system they use and whether it is a two-component professional system or a two-component kit product. Ask how they verify mixing ratios and what their process is if something goes wrong. Ask for references from Saint John-area projects you can actually call. Ask whether they will provide a written warranty on their work and what it covers.

The Saint John market has a mix of experienced, well-equipped spray foam contractors and occasional operators who have purchased entry-level equipment and are learning on the job. The stakes are too high to be someone's learning experience — spray foam applied incorrectly to your rim joists, basement walls, or cathedral ceiling is not a project you can easily undo.

New Brunswick Insulation can match you with experienced spray foam contractors in the Saint John area at no cost. You can also browse the insulation contractor directory through the New Brunswick Construction Network at newbrunswickconstructionnetwork.com/directory?category=insulation to find and compare local professionals before you commit.