Hey folks, I'm Andy, co-founder of BEEST, and my family makes spray foam for people who build their own stuff.

Every fall the same message lands in my inbox.

“I built a shed. I love it. And I can't use it four months a year.”

Too hot to work in August. Too cold to feel your fingers in January. Tools rusting on the bench.

So here's what I tell every one of them.

Your shed isn't cold because it's small. It's cold because of what's between you and the weather.

Nothing.

Give me five minutes. I'll show you why, why nobody at the shed lot mentioned it, and how one weekend fixes it for good.

Why Everything You've Tried Hasn't Worked

If your shed is useless half the year, I'd bet you've tried most of this:

• Ran a space heater. It heats the air. The air leaves through the seams as fast as you make it.
• Put a fan in the window in August. Moves the hot air around. Doesn't make less of it.
• Stapled up foil bubble wrap. A thin shiny layer with a gap at every stud. The heat walks right past it.
• Bought a few cans of gap filler. One can did one corner.
• Priced a crew. They wanted a minimum charge for a 10x12 box, if they called back at all.

None of it worked. And here's the part nobody told you: none of it touches the root cause.

The Hidden Root Cause: Your Shed Has Skin, Not Walls

A house wall has layers. Siding, sheathing, insulation, drywall.

A shed wall has one. Siding nailed to studs. That's it.

At 2 pm in August the sun hits the siding. The siding gets hot. There's nothing between it and you, so the air inside heats up with it.

January works the same way in reverse. Every bit of heat you make goes straight out through that one thin layer.

Then there are the seams. Where the wall meets the floor. Where the rafters land on the top plate. Every one of them breathes.

That's the root cause. Not the size. Not the heater. Thin walls and open seams.

Why Nobody Told You This

The shed lot sells you the box. Nobody mentions the box isn't finished.

I'm not going to tell you foam crews are crooks. They're not. But a crew has a truck, a rig, payroll and insurance. They need jobs worth the drive.

A 10x12 shed is about 3 kits of foam at 1 inch. Most crews won't come out for that. The ones who do charge a minimum.

And the cans at the hardware store? Made for a door frame, not 490 square feet of wall and roof.

So the shed sits there. Usable in spring and fall. Tools rusting the rest of the year.

The Fix Is Simpler Than Anyone Let On

Thin walls and open seams are one problem. So the fix has to do two jobs at once.

Seal every seam. Insulate every bay. In one pass.

That's what spray foam does. It expands into the gaps, then it sets into a layer of insulation on the siding and the studs.

And that's why we built FullStop as a 12-can kit with a real metal gun, not a single can.

• 12 cans and a metal gun. A 10x12 shed is about 3 kits at 1 inch. Buy the pack that fits the job. No compressor. No rental.
• R-4.12 per inch. Two 1-inch passes get you R-8.24 at 2 inches.
• DualCore foam. A closed-cell outer skin with a flexible center. People ask us open or closed cell. It's a blend of both.
• Class A fire-rated. Cured FullStop tested ASTM E84 with a Flame Spread Index of 0.* Your local code still decides whether it needs an ignition or thermal barrier, so check with your inspector.
• Gloves, goggles and a coverall in the box. Plus a metal gun and cleaner. Bring your own respirator.
• Sticks to wood, metal, concrete and drywall. Metal shed? Fine. The surface just has to be dry and 41F or warmer.

How a Weekend Goes

Here's the job, start to finish.

1. Warm the cans to 68F. Leave them in the kitchen overnight. The shed surface and air need to be 41F or warmer.
2. Check that it's dry. Never spray wet wood or wet metal. Run any wiring first.
3. Suit up. Respirator, gloves, goggles, coverall. Every time.
4. Practice on cardboard. Five minutes with the gun and you've got it.
5. Spray each bay in a 1-inch pass. Seams first, then the field. Walls Saturday, roof Sunday. Overhead work uses more foam, so plan for it. Let each pass set. Second pass for 2 inches.
6. Air it out. Doors open, fans on. Give it 24 to 72 hours before you move the tools back in.

Keep flames, sparks and pilot lights away while you spray and until the vapors clear. Follow the instructions in the box.

How Many Kits Does a Shed Take?

This is the first question everyone asks. Here's the honest math.

One kit is 12 cans, rated 240 sq ft at 1 inch on paper. Real use runs about 70% of that. That's our estimate, not a lab test.

Measure every wall and the roof. Multiply height by length for each one and add them up. Then use this table.

Real use, rounded up. Overhead work uses more.

Don't buy one kit for a whole shed. We'd rather you plan right than run short halfway up a wall.

One buyer put it best: “Covers less than you think it will, plan ahead.”

A 12x24 is a big job. Get a crew quote too and compare. The kit shines on the sheds a crew won't drive out for.

Use the calculator →

What Happened in Other People's Sheds

“This stuff is amazingly easy to install. I received it quickly and I did my whole shed without any help.”

“I had no experience with spray foam prior to attempting insulating my 10x16 shed.”

“Surprised how easy this was. I had never used spray foam before this but it really was pretty simple after about 5 minutes.”

“Was nice to be able to speak with someone.”

FullStop customer reviews, Judge.me. Verbatim.

We asked our customers what changed after the job:

Customer-reported, individual experiences vary. Not a promise of savings from BEEST.

The Questions I Get Before People Buy

Will it stick to a metal shed?

Yes. Wood, metal, concrete and drywall. The surface has to be dry and 41F or warmer.

It looks thin. Does it really insulate?

One pass is about an inch at R-4.12. Two passes get you R-8.24 at 2 inches. Thin passes cure better than one thick one.

Is it flammable?

While you spray and before it cures, yes. Keep flames, sparks and pilot lights away until the vapors clear. Cured FullStop is Class A fire-rated (ASTM E84), Flame Spread Index 0.* Your local code decides whether it needs an ignition or thermal barrier.

Can I do it in stages?

Yes. Walls this month, roof when the budget allows. We sell can packs for refills so you don't buy a second gun.

I've never sprayed foam. Can I do this?

Plenty of our buyers had never touched foam before. Practice on cardboard, spray thin passes, let each one set, and you'll be fine.

Isn't it cheaper somewhere else?

The kit comes with a metal gun, cleaner, gloves, goggles, a coverall and video help. And a person who picks up the phone when you have a question halfway through the job.

Is this a real company?

We're BEEST, a family-owned company. Call us before you order and a real person answers: 1 (800) 540-4671.

Here's What I'd Do This Weekend

Go stand in your shed this afternoon. Put your hand flat on the wall.

Then do it before it gets too cold to spray. FullStop needs 41F or warmer, surface and air. In most of the country that window is closing.