The Top 5 Spray Foam Mistakes — And How to Avoid Them
Spray foam insulation is a powerful solution—but only when applied correctly. Whether you’re just starting out or have years of experience, even seasoned pros can make costly mistakes that lead to callbacks, wasted materials, or job site delays.
At T4 Supply, we’ve worked with hundreds of contractors and seen it all. Here are the top 5 mistakes we see—and how you can avoid them every time.
❌ 1. Skipping Substrate Prep
The Mistake: Spraying directly onto dirty, damp, or oily surfaces.
The Fix:
Always check moisture levels and surface temp.
Use brushes, vacuums, or mechanical prep tools to clean thoroughly.
For metal, don’t forget primers or adhesion-promoting coatings when needed.
❌ 2. Incorrect Temperature or Pressure
The Mistake: Inconsistent pressure or cold material causes poor mix and off-ratio foam.
The Fix:
Pre-heat drums and maintain proper hose temps.
Confirm gun pressure and proportioner calibration.
Monitor job site and equipment temperatures constantly.
❌ 3. Improper Spray Technique
The Mistake: Overlapping passes incorrectly, spraying too fast or too thick in a single pass.
The Fix:
Use smooth, consistent motions.
Apply in multiple light passes (usually <2" each).
Maintain 12–18 inches distance from the surface.
❌ 4. Ignoring Safety & Ventilation
The Mistake: Working in enclosed spaces without airflow or protection.
The Fix:
Use full PPE (respirator, suit, gloves, goggles).
Set up fans or negative-air systems to ventilate.
Train your crew—not just on application, but safety too.
❌ 5. Using the Wrong Product for the Job
The Mistake: Spraying open-cell where closed-cell is required—or vice versa.
The Fix:
Know code requirements and building envelope needs.
Review climate zone guidelines.
Ask our team—we’ll help you choose the right foam or coating for the job.
🧠 Bonus Tip: Train and Re-Train
Even experienced crews need refreshers. When the rig is acting up or jobs feel off, step back and review fundamentals. Our support team offers tech guidance and product insight to help you course-correct fast.
📞 Need help troubleshooting or choosing the right foam? Contact T4 Supply.
🌐 Visit www.t4supply.com or call us directly to speak with a spray foam expert.
