4.7 stars | Trusted by 5,000+ DIYers Sealing Crawl Spaces & Basements
BEEST FullStop™ Basement & Crawl Space Spray Foam Kit
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4.7 stars | Trusted by 5,000+ DIYers Sealing Crawl Spaces & Basements
R-Value 8.24
240 sq. ft. per kit
Right-Sized for Targeted Jobs
BEEST FullStop™ Basement & Crawl Space Spray Foam Kit
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Seal rim joists, basement walls, and crawl spaces yourself — without overcommitting to a contractor
Kit includes everything to seal a crawl section in a few hours — no extra runs to the hardware store
Perfect for crawl spaces, rim joists, basement walls, and tight subfloor sections
Free Crawl Space & Rim Joist eBook
$19.99
FREE
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$29.99
FREE
1x Cleaner Cans
$19.99
FREE
Metal Foam Gun
$49.99
FREE
Safety Kit
$34.99
FREE
Estimated Delivery By:
1 Set of Free Gifts Per Order
10 Year Warranty
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American Owned
Product Details
Beest FullStop™ Spray Foam — Technical Specifications
Polyurethane-based, single-component spray foam.
Designed for high-density insulation and long-term thermal performance.
R-Value:
R-Value per Inch: 4.12
R-Value per 2": 8.24
High thermal resistance for consistent temperature control
Application & Coverage:
Recommended Spray Thickness: 2" (optimal for max R-Value).
Coverage (per 12 cans):
~240 sq. ft. at 1"
~120 sq. ft. at 2" (two 1" coats recommended).
Suitable for cavities, gaps, and uneven surfaces.
Cure & Expansion:
Full Cure Time: Approximately 6 hours
Expansion Rate: High — expands to fill and seal voids for an airtight, rigid structure
Adhesion & Substrate Compatibility:
Bonds effectively to wood, metal, concrete, drywall, and OSB
Engineered for both smooth and irregular surfaces
Operating & Application Conditions:
Recommended Application Temperature: 68–77°F (20–25°C)
Service Temperature Range: -40°F to +176°F
Maintains structural integrity across temperature variations
Appearance & Finish:
Cures to a hard, durable surface that can be trimmed or coated after curing.
Common Application Areas:
Rim Joists
Sill Plates
Crawl Space Walls
Block & Stem Walls
Sub-Floor Bays
Foundation Cracks
Air Sealing
Moisture Block
Pest Block
High R-Value
Air Sealing
Moisture Block
Pest Block
High R-Value
Air Sealing
Moisture Block
Pest Block
High R-Value
Air Sealing
Moisture Block
Pest Block
High R-Value
3 Reasons FullStop Stops Your AC From Working Overtime
Stop AC From Bleeding Out the Foundation
The rim joist is the largest hidden air leak in most homes. In summer it lets AC sink into the crawl while hot, humid outside air rushes back into the living space — forcing the system to run nonstop. Sealing it is the single highest-leverage fix for AC efficiency and indoor humidity below grade, and one kit handles a typical run.
Block Moisture and Pests Without a Separate Barrier
Closed-cell foam doesn't absorb water, won't grow mold, and won't attract rodents. One product replaces fiberglass + vapor barrier + caulk — and lasts decades below grade, exactly where every other material eventually fails.
Class A Fire Rated
Meets ASTM E84 with a flame spread index of 0 — the highest fire safety classification available. Code-approved for residential basements and crawl spaces, so it meets the standard inspectors require below grade.
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Professional-Grade Sealing for Basements & Crawl Spaces
Everything you need to seal a rim joist run, basement wall, or crawl section correctly — without overbuying or hiring out.
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Will this actually take strain off my AC and reduce humidity above grade?
Yes. The rim joist is the largest hidden air leak in most homes — in summer it lets AC sink into the crawl while hot, humid outside air rushes back into the house, forcing the system to run nonstop. Sealing it is the single highest-leverage fix for AC efficiency, indoor humidity, and pest control below grade.
Will the foam handle the moisture in a crawl space or basement?
Yes. BEEST FullStop™ acts as both a vapor and air barrier — closed-cell foam doesn't absorb water, won't grow mold, and won't degrade in a damp crawl space.
Is one kit too much for a small rim joist or section job?
It's right-sized. One kit covers ~240 sq. ft. at 1" — enough for a typical rim joist run or a small crawl section, with no contractor markup. Use only what you need; the rest stores for the next project.
Will it work in tight, awkward joist spaces?
Yes — that's where it's strongest. The foam expands to fill irregular gaps and bonds to wood, concrete, and block. Honest note: standard-height cans can be tight in shallow joist bays — short blasts and patience handle it.
How long will the seal last down there?
Decades. Once cured, the foam is rigid, moisture-resistant, and pest-resistant — a one-time fix for a problem that usually keeps coming back with batts or fiberglass.
Still Have Crawl Space Questions?
Send the perimeter measurement and a photo if you can — we'll size the kit so you don't overbuy.
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Where Owners Use FullStop Below Grade
Rim Joist
Sill Plate
Crawl Space Walls
Block Walls
Mud Sill
Sub-Floor Bays
HVAC Pass-Throughs
Plumbing Drops
Vent Penetrations
Sump Pit Edges
Stem Walls
Foundation Cracks
Pipe Wrap Boxes
Crawl Hatches
Knee Walls
Rim Joist
Sill Plate
Crawl Space Walls
Block Walls
Mud Sill
Sub-Floor Bays
HVAC Pass-Throughs
Plumbing Drops
Vent Penetrations
Sump Pit Edges
Stem Walls
Foundation Cracks
Pipe Wrap Boxes
Crawl Hatches
Knee Walls
Seal Your Basement Or Crawl Space In Three Simple Steps.
From rim joist to crawl space wall, BEEST FullStop™ creates a moisture- and air-tight seal exactly where you need it — no contractor, no overkill.
1
Prep the Section
Clear the area, dry the surface, and lightly mist for grip. Suit up with the included PPE before crawling in.
2
Spray the Target Area
Shake cans, attach the gun, and test the flow. Lay short, controlled passes along the rim joist or block wall. Two 1" coats reach 2" without waste.
3
Cure and Done
Allow ~6 hours to cure. Trim flush against joists or block. No follow-up, no callback, no contractor.
Targeted, Long-Lasting Sealing Where You Need It
High-performance foam designed to seal targeted leaks, block moisture, and lock out pests below grade.
94%
Noticed cooler, less humid main floors after sealing rim joists and crawl walls.
89%
Completed a crawl space or rim joist run without a pro.
91%
Reported less AC strain and lower indoor humidity after sealing the foundation.
87%
Would recommend BEEST FullStop for basements and crawl spaces.
Low Expansion Thermal Foam
Strong Below-Grade Seal
Moisture, Air & Pest Barrier
How FullStop Beats Fiberglass Down Below
High-performance foam that seals air, blocks moisture, and locks out pests — exactly where you need it.
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Performance
Energy Savings
Material Quality
Air Sealing
Moisture Protection
High-R-value thermal insulation (R-8.24 at 2")
Reduces AC strain and indoor humidity by sealing the foundation
Closed-cell, rigid, won't absorb water below grade
Seals rim joists, sill plates, and foundation cracks
Acts as vapor, moisture, & pest barrier
Fiberglass / Foam Board
Lower R-value per inch
Doesn't address rim-joist air leakage
Soaks up groundwater and grows mold
Lets moisture in, invites pests
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Why This Outperforms Fiberglass Below Grade
Remove the moisture issues, the settling, and the wasted material from a below-grade job.
Consistent Application
Maintains steady spray across awkward joist bays and block walls without losing pressure.
No Mid-Job Failures
Prevents the strap and pressure failures that are especially painful when you're already on your back in a crawl space.
Built for Repeat Use
Built for problem-solvers who'll come back for the next rim joist, crawl section, or cold-floor fix.
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Reinforced
Rigid Core
Helps Minimize Floor Squeaks & Drafts
All-in-One Below-Grade Sealing
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