How we researched this guide
We compared RV leveling blocks and home-gym floor levelling, checked maker spec sheets and manuals, and read owner reports and independent roundups before writing a word. Nothing here is based on hands-on testing by us, and no specification is printed unless a maker document, a maker listing, or a named independent source states it.
Where a figure could not be confirmed against a maker source, we left it out and said so, rather than guessing. The honest finding first: RV leveling blocks are not gym equipment. This guide explains what they are, why they do not transfer to a home gym, and what actually levels a gym floor.
The 30-second answer
RV leveling blocks do not belong under gym equipment. They are interlocking plastic blocks and drive-on ramps made to level a recreational vehicle by lifting its tyres — Camco FasTen blocks add one inch per block and stack to a 4.5-inch limit, and the Andersen Camper Leveler works only by driving a tyre onto a curved ramp. A home gym floor is levelled with self-levelling compound, plywood wedge platforms, or steel shims under rack feet — never with RV blocks, which no maker rates for that use.
What leveling blocks actually are
Leveling blocks are RV products. Camco FasTen blocks are interlocking 8.5 by 8.5 inch plastic blocks, one inch thick each, sold in 10-packs, and Camco rates them for single wheels, double wheels, hydraulic jacks, tongue jacks, stabiliser jacks, fifth-wheel jacks and tandem axles. The stack limit Camco states through retailer summaries is 4.5 inches high. Tri-Lynx Lynx Levelers are the same idea — interlocking blocks rated to 40,000 lb with a 10-year warranty, for RV tyres only.
The Andersen Hitches Camper Leveler 3604 is different in form but the same in purpose: a curved drive-on ramp. You drive the tyre onto it until the RV is level, then chock it. It is rated to 30,000 lb and lifts up to 4 inches, for tyres up to about 31 inches. The mechanism needs a tyre. There is no tyre under a power rack or a treadmill, so the mechanism cannot transfer to gym equipment at all.
No maker document we found rates or recommends any of these blocks for gym use — not under a rack, not under a treadmill, not under flooring. That absence is the whole story of this guide.
Why RV blocks do not work under gym equipment
Point loading
A rack foot concentrates hundreds of pounds onto a few square inches. RV blocks are rated for a tyre spreading load across a wide contact patch, not for a small steel foot pressing down on one spot. No maker publishes a point-load rating for them, and using them that way would be an unevidenced safety claim.
Dynamic load
A loaded barbell dropped onto a rack, or a lifter moving under load, creates dynamic forces no RV block is rated for. A block that cracks or slips under a rack is a serious injury risk, and no maker endorses the use.
The Andersen ramp cannot work at all
The Camper Leveler only functions when a tyre is driven onto its curved surface. Static gym equipment has no tyre and no drive-on motion, so the product is physically inapplicable.
Stability and slip
Interlocking RV blocks are designed to sit on flat ground under a tyre. Under a rack foot they can shift, tilt, or compress unevenly, and there is no published test of their behaviour under gym loads.
What actually levels a home gym floor
| Method | How it works | Best for |
|---|---|---|
| Self-levelling compound | Cement underlayment poured over the slab | Whole garage floor, 1/4 to 1.5 in per lift |
| Plywood wedge platform | Staggered thin plywood under a lifting platform | Compensating a slope under a platform |
| Steel shims | Thin steel plates under rack feet | Small height differences at rack feet |
| Rubber gym mats | Thick mats over the slab | Comfort and protection, not levelling |
| Timber firring | Tapered timber strips under a built floor | Garden rooms and garage conversions |
Self-levelling compound
Garage slabs are usually pitched 1/8 to 1/4 inch per foot for drainage, which is enough slope to matter under a lifting platform. EngineerFix’s guide to levelling a garage floor for a home gym prescribes diagnosing the slope first, then pouring self-levelling underlayment in lifts of 1/4 inch to 1.5 inches, rated over 4,000 psi for heavy equipment. This is the correct fix for a whole-floor slope, and it is the only method that gives a genuinely flat surface under the whole gym.
Compound work is messy and needs the floor clear, the slab primed, and the pour done in one pass. It is also permanent. For a rented garage, it is usually not an option — which is why the plywood platform below exists.
Plywood wedge platforms
TwoRepCave’s guide to a sloped garage gym floor prescribes staggered thin-plywood wedges under a lifting platform, compensating a drop of about 2 inches over 8 feet. The platform itself is built flat on top of the wedges, so the bar and the lifter stand on a level surface even though the slab below is not.
This is the practical answer for most home gyms: build the platform level, not the floor. It is reversible, it costs little, and it does not need landlord permission.
Steel shims under rack feet
For small differences — a rack foot that rocks because the slab dips under one corner — steel shims under the rack feet are the standard fix. TwoRepCave describes 7 by 5 inch steel shims, 1/4 inch or 5/64 inch thick, under rack feet. Shims are cheap, precise, and removable, and they do not compress under load the way plastic blocks can.
Check the rack is level with a spirit level across the uprights after shimming, and re-check after the first heavy session. A rack that rocks under load is a rack that needs re-shimming, not more weight on it.
What rubber mats do — and do not do
Rubber gym mats protect the floor and deaden dropped weights, but they do not level anything. A mat over a sloped slab is still sloped. Mats are a finishing layer over a level platform or a levelled floor, not a levelling method.
Safety essentials
Safety essentials
- Never place a rack on an unlevel surface and hope the weight holds it still.
- Check the rack is level with a spirit level before every heavy session.
- Do not use plastic RV blocks, foam, or stacked cardboard under rack feet.
- Bolt the rack to the platform or floor where the maker allows it.
- Keep the lifting area clear of loose shims and offcuts.
- If the floor slope is more than 2 inches over 8 feet, level the floor or the platform — do not shim the difference.
Troubleshooting
| Symptom | Cause | Fix |
|---|---|---|
| Rack rocks | Slab dips under one foot | Steel shims under the low foot |
| Bar rolls on the platform | Platform not level | Re-level wedges under the platform |
| Floor feels uneven | Slab pitched for drainage | Self-levelling compound or a wedge platform |
| Mats bunch up | Mats over a slope | Level the surface first, then lay mats |
| Rack feet sink | Soft or damaged floor | Spread the load with a plywood platform |
Who should NOT buy RV leveling blocks for a gym
Everyone building a home gym. RV leveling blocks are for RV tyres and jacks. They are not gym equipment, and no maker rates them for gym use.
Renters looking for a quick fix. A plywood wedge platform is the renter-friendly answer. RV blocks are not a shortcut to it.
Final verdict
Do not buy RV leveling blocks for a home gym. Level the floor with self-levelling compound, build a level plywood platform, or shim the rack feet with steel. The blocks belong under an RV, and that is where they should stay.
Frequently asked questions
Can I use RV leveling blocks under a power rack?
No. No maker rates RV leveling blocks for gym equipment, and a rack foot point-loads the block in a way no tyre does. Use steel shims under rack feet instead.
What are leveling blocks for?
Levelling a recreational vehicle by lifting its tyres or jacks. Camco FasTen blocks add one inch per block up to a 4.5-inch stack, and the Andersen Camper Leveler is a drive-on ramp for tyres up to about 31 inches.
How do I level a sloped garage floor for a home gym?
Diagnose the slope, then either pour self-levelling compound in lifts of 1/4 inch to 1.5 inches, or build a plywood wedge platform that is level on top. Steel shims fix small differences at rack feet.
How much slope does a garage floor have?
Garage slabs are usually pitched 1/8 to 1/4 inch per foot for drainage. That is enough to matter under a lifting platform.
Do rubber gym mats level a floor?
No. Mats protect the floor and deaden dropped weights, but a mat over a sloped slab is still sloped. Level first, then lay mats.
What size steel shims go under a rack?
Guides describe 7 by 5 inch steel shims, 1/4 inch or 5/64 inch thick, under rack feet. Check level with a spirit level after shimming.
Can I use the Andersen Camper Leveler in a gym?
No. It only works by driving a tyre onto a curved ramp. Static gym equipment has no tyre, so the mechanism cannot work.
Is a plywood platform better than levelling the whole floor?
For most home gyms, yes. A wedge platform is cheaper, reversible, and does not need the floor cleared or primed. Levelling compound is the better answer only when the whole floor must be flat.
Sources & changelog
Sources
- EngineerFix — How to Level a Garage Floor for a Home Gym
- TwoRepCave — How to Deal with a Sloped Garage Gym Floor
- Amazon — Camco FasTen Leveling Blocks 44510
- Amazon — Andersen Hitches Camper Leveler 3604
- RV Expertise — RV Leveling Blocks
- Screwfix Community — Garage Floor Leveling for Home Gym
Changelog — November 5, 2026: guide first published.
By Leo, Founder, WinchInsider
Leo founded WinchInsider to give working owners straight, research-based buying guides — maker specs first, owner reports second, and no claim we cannot source.