How many cans will get you to the last wall?
Featuring Scott Schuyler
You're ready to order. Then one small question stops you: will the box get you to the last wall?
Picture the job halfway done. One wall covered. The next one started. You reach for another can, and the box is empty.
That's the moment you're trying to avoid when you ask, 'Is 12 cans enough?'
Fair question. You've measured the building. You've watched the video. You'd just like someone to give you a number that fits your project.
Let's walk through a 10x20 example. The first surprise comes before we count a single can.
The first number looks smaller than the job.
A 10x20 room is 200 sq ft. So it's easy to see a coverage figure near that number and think you're close.
Then you lift the tape measure off the floor.
With 8-foot walls, those four sides add up to 480 sq ft before openings. That's a 60-foot perimeter, multiplied by 8 feet of height.
Same room. Much more surface to spray. And we haven't included the ceiling or floor. This is a walls-only planning example.
The door and window give a little back.
Now the estimate starts looking more like your building.
There's no reason to count a door as a wall you're going to spray. In our example, a 3x7 door takes away 21 sq ft. A 3x4 window takes away another 12.
That brings the wall area down to 447 sq ft.
Your openings will be different. But this is the useful part of measuring: you can point to every surface in the total. It isn't just a number borrowed from somebody else's project.
Then comes the question that changes the order.
How thick are you planning to spray?
One can is rated for up to 20 sq ft at 1 inch. At 2 inches, that becomes 10 sq ft on paper. The same material is being spread twice as deep.
FullStop is rated R-4.12 per inch, or R-8.24 at 2 inches. The thickness you need depends on your building and its requirements.
So that choice has to come before the can count. Otherwise, a smaller order can look right simply because it's based on a thinner layer.
The wall isn't the only place foam gets used.
This is the detail that's easy to miss while you're looking at coverage numbers.
Your practice pass uses foam. So do the awkward little gaps. And the first section may take more while you're getting a feel for the gun.
Paul Bean brings this up in his published review. He recommends allowing extra for practice and the nooks that need filling.
For our estimate, we'll plan around 70% of rated yield. That's a planning allowance, not a guarantee. Difficult access and overhead work can use more.
Now the bigger box has a reason.
Back to those 447 sq ft of walls.
At 2 inches, rated coverage works out to 44.7 cans. Using our 70% planning yield brings that to about 63.9. Round up, and the estimate is 64 cans.
Two 36-packs would give this example 72 cans. A 12-can kit would leave a lot of wall unfinished.
That's why the pack size matters. It follows the job. These numbers are an illustration, not the measured can count for the room in the photo, and they include no ceiling or floor.
Your first section tells you something useful.
Once you start your own job, keep the tape measure nearby.
Note the area you've covered, the thickness and the cans used. You now have something better than a guess about how your application is going.
It's tempting to count stud bays from a video. But taller bays, wider gaps and deeper foam change how far a can goes. A finished-looking wall doesn't tell you its depth.
Checking early gives you a chance to adjust before you're looking at the last can and a wall still to go.
One more look at what's actually in the box.
Once the can count makes sense, it's easy to feel finished with the order.
Take one more look. Are you buying a kit with the gun and cleaner, or a refill pack? Does the offer include one accessory set per order? More cans don't always mean another set of equipment.
You'll also need masking supplies and a suitable respirator. Check the exact contents of the pack you've selected.
This is the quiet part of a smoother job: having what you need laid out before you begin.
Let's put your building in the calculation.
The 10x20 example has done its job. Now it can get out of the way.
Use your wall heights, your openings and your planned thickness in the project calculator. Add any other surfaces you're going to spray, and allow for practice.
If the total surprises you, call BEEST and talk it through. It's worth checking while the order is still a plan.
Then choose the pack combination that gets you to the end of your job. That's the number you were looking for in the first place.
Use the project calculator Call BEEST
FullStop foam includes a 1-year limited warranty. Register within 30 days of purchase for a free extension to 10 years. The extension covers the foam; the gun has a 1-year limited warranty. Read the warranty terms.
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