I’m Kayla, and yes, I actually used DIY spray foam. Twice now. (If you’re curious how someone else tackled a similar project, this breakdown of what they learned and would do again is a helpful read.) I live in a drafty 1950s house in Michigan, where January wind sneaks under the sill and laughs at socks. I got tired of the cold crawl in our basement and the weird chill in the kid’s playroom. So I rolled the dice on DIY foam. Gloves, suit, big green tanks—the whole thing.
Let me explain what went right, what went sideways, and what I’d do if you’re thinking about it too.
Why I Tried It
- The basement rim joists were leaking air. You could feel it on your hands.
- Fiberglass helped a bit, but it got damp and sad.
- Hiring a pro was pricey for a small job. My quote was over $2,000 for the rim joists and an attic hatch. My budget said “nope.”
National averages suggest DIY kits will run about $1.00–$2.25 per square foot (see the current numbers at HomeGuide), which helped me decide to give it a shot.
So I tried two kits on two projects:
- Froth-Pak 210 for the basement rim joists.
- Foam It Green 602 for the garage ceiling over the playroom.
- I also used a few cans of Great Stuff Pro around the attic hatch and gaps.
Different sizes, same basic idea—mix two parts and spray. It grows. It hardens. It seals.
What I Used (and How I Prepped)
- Closed-cell spray foam kit (Froth-Pak 210)
- Closed-cell spray foam kit (Foam It Green 602)
- Great Stuff Pro cans for small cracks
- Half-mask respirator with organic vapor cartridges
- Goggles, Tyvek suit, nitrile gloves, boot covers
- Box fans and a cheap temp gun
- Drop cloths, painter’s tape, plastic sheeting, and cardboard
I warmed the tanks to about 75°F. That part matters. Cold tanks make weird foam. I set them near a space heater for an hour (not too close), and once I even set the hoses in a bucket of warm water. Seemed odd, but it helped.
First Job: Basement Rim Joists (Win)
The rim joists were my test run. I taped plastic around the laundry area and moved the cat’s litter box upstairs. I’m not kidding—the smell on day one is real.
With Froth-Pak 210, I did short, even passes. Sweep. Pause. Sweep. You keep the gun moving like you’re frosting a cake you’re not allowed to ruin. I aimed for thin layers, about half an inch per pass. Closed-cell grows fast and gets hard.
I hit:
- All rim joist bays
- Pipe and wire gaps
- Sill plate edges
It took me two hours, plus cleanup. By that night, the basement felt less sneaky. The cold draft was gone. The dehumidifier didn’t run as much either. R-value kicked in, but the air seal did the heavy lifting.
Second Job: Garage Ceiling Over the Playroom (Mixed)
I used Foam It Green 602 for the bigger area. Another DIY sprayer shared what actually happened during their garage ceiling adventure, and I wish I’d read it first. Here’s where I blew it:
- I sprayed too thick in a few spots. It got spongy. I had to scrape and redo.
- I didn’t mask every single brace. The overspray got on a metal bracket and, well, it’s still there.
- One nozzle clogged because I paused too long. Foam cured in the tip, and I lost time swapping it.
Still, the room above warmed up by a few degrees. Fewer cold spots. It felt less “my feet are ice” and more “I can sit here with a blanket.”
Quick Wins I Didn’t Expect
- The attic hatch. I used Great Stuff Pro around the frame and weatherstrip on the lid. Huge improvement for a small spend.
- The band joist near the kitchen smelled better. Weird, right? Turns out tiny gaps were pulling in musty crawl air. Foam sealed it off.
- The furnace didn’t run as long during the night. You can hear the difference.
Mistakes I Made (So You Don’t)
- Foam thickness: More is not better. Thin passes work. Let it cure between layers.
- Temperature: Cold tanks make crumbly foam. Warm them. Warm the room if you can.
- Stopping mid-spray: If you pause, change the mixing tip. I didn’t once. It cured in the nozzle. Lost about 10 minutes and a chunk of material.
- Mask everything: Floor, brackets, the washer, the water meter—whatever is in range. Overspray travels like gossip.
- Smell care: Vent the area with two fans. One blowing in, one out. The smell faded after about 24 hours for me. Day two felt normal.
If you want a play-by-play of how it actually went for another weekend warrior, that recap shows plenty of the same hiccups I hit.
Safety Stuff I Actually Used
- Respirator with fresh cartridges
- Goggles (foam dust flakes off when you trim)
- Full suit and gloves
- Long socks or taped ankles (foam finds skin)
- Work light (you need to see shadows to hit gaps)
I also kept acetone on hand. If foam is wet, acetone wipes it off tools fast. If it dries, it’s forever. Ask the tiny dot on my wedding ring.
Cost: What I Paid vs. Quotes I Got
- Froth-Pak 210: About $400 at the time I bought it
- Foam It Green 602: Just under $900 during a sale
- Great Stuff Pro cans: Around $12–$18 each
- Gear (mask, suit, misc.): Around $120 total
Rough math put me near $1,500 for all projects, gear included. My pro quotes for the same areas ran between $2,800 and $3,600. If you’re still wondering whether spray foam is actually cheaper to tackle yourself, this in-depth comparison breaks down the numbers line by line.
For big attics or roof decks, a pro can be worth it. For small jobs like rim joists, DIY made sense for me.
Open-Cell vs. Closed-Cell (Plain Talk)
- Closed-cell: Hard, strong, water resistant, higher R per inch, acts as a vapor retarder. Good for rim joists and small, cold, leaky spots.
- Open-cell: Softer, cheaper per inch, great for sound, not a vapor barrier. Good for interior walls and sound control.
I used closed-cell both times. Michigan winters, you know?
Code, Heat, and “Do Not Foam Here” Notes
- Keep foam away from hot flues, chimneys, and recessed lights that aren’t rated.
- Some areas need a fire barrier or intumescent coating over foam. Check your local code.
- Don’t bury junction boxes. Mark them, keep access.
- If you feel unsure, call your local inspector. They saved me from foaming near a vent pipe that ran hot.
Little Things That Helped A Lot
- Practice spray on cardboard first. You’ll see how fast it grows.
- Keep the gun 12–18 inches away for even coats.
- Number your bays and work in a loop so you don’t miss one.
- Sharp handsaw for trimming cured foam.
- Box fan in the window. Tape the gaps so air actually moves.
Real Results at Home
- Basement: Warmed up, less musty, no more cold ankle draft by the washer.
- Garage ceiling over playroom: Fewer cold corners, heat runs less, still not perfect because of the door leaks—but better.
- Attic hatch: Night-and-day change from a tiny job.
- Bills: I’m not claiming miracles. But my winter gas bill dropped about 8–10% compared to a similar cold stretch last year. Close enough for me.
What I Didn’t Like
- The smell on day one. Headache city if you skip the mask.
- The mess. Foam sticks to everything. It laughs at scrubbing.
- Coverage claims felt… optimistic. I lost about 10–15% to waste, tips, and my learning curve.
- It’s loud when you’re moving around in gear. My dog hated the fans.
Would I Do It Again?
Yes—for rim joists, attic hatches, and small zones. For a full roof deck or a giant attic? I’d likely hire a crew. It’s a lot to manage, and they spray cleaner and faster than I can. If you’d rather skip the gear and get professional help, grab a quick estimate from the pros at Service Center Team and see how the cost stacks up against DIY.
Who Should Try DIY Spray Foam
- You have small, leaky areas: