ICC Certified
IBC & IRC Compliant
4.9/5 Rating
433 Verified Reviews
25-Year Warranty
Industry Leading
At Lowe's Nationwide
In-store & Online
150,000+ Builds
Across USA
Not Sure How Many TuffBlocks You Need?

Jerry & Sierra (Site Built Sheds)
“TuffBlocks have turned building the deck foundation - once one of the hardest, most labor-intensive parts - into a quick, easy process.”

Russell (Shedscape)
“TuffBlocks let us build perfectly level shed foundations on sloping yards - faster, cleaner, and more professional than concrete.”

Justin (DIY)
"Strong, easy to use, and helped save me tons of time and energy building the frame of our deck!"
verified customer reviews
What Builders & DIYers are Saying






Why thousands of builders replace concrete with TuffBlock every year.
| Feature | TuffBlock | Concrete Footings | Concrete Deck Blocks |
|---|---|---|---|
| Digging Required | No | Yes | No |
| Concrete Required | No | Yes | No |
| Build Same Day | ✔ | x | ✔ |
| Weight Per Unit | 1.5 lbs | Heavy | Heavy |
| Low Deck Height | ✔ | x | x |
| No Cutting Or Grinding | ✔ | x | x |
| Won't Crack Or Corrode | ✔ | x | x |
| 25-Year Warranty | ✔ | x | x |
Real-World Foundation Comparison
Based on a 12' x 12' Floating Deck
Concrete Footings
~1,400–2,000 lbs material handled
9–14 hours setup
(+ up to 24 hours curing time)
Concrete Blocks
~720 lbs handled
2.5–3 hours setup
TuffBlock
~27 lbs handled
45–70 minutes setup

*Compared to traditional concrete footings

One Foundation Block.
Every Build.
TuffBlock is a lightweight, load-rated composite deck block - engineered to replace concrete footings for any low-to-medium profile outdoor structure.
Place it on compacted ground. Level it. Build. Works on soil, gravel, turf, or pavers. Proven on 150,000+ builds across North America.
Download Installation Guide here.

Perfect for: Floating decks, low-profile builds, sheds, playhouses, platforms, walkways & more.
TuffBlock works on almost any surface including soil, gravel, turf, or pavers.

Ultra-low profile decks

Raised decks

Variable height decks

Intermediate footing decks
| Specification | Instant Foundation System |
|---|---|
| Dimensions | Total Height 4.5"; Height from slot 2", Length 11.81"; Width: 11.81" |
| Weight | 1.5lbs |
| Material | High strength closed loop recycled polyolefin material with an ultra-high UV rating |
| Load Rating | 1,700 lbs & break tested to 11,000 lbs |
| Stirrup Width | Suits 1.4"-1.6" or 1.4"-2" joists and bearers as well as 3.5"-4" posts |
| Warranty | 25-Year Warranty. Zero warranty claims to date. |
| Shipping | Free shipping across. No heavy lifting. No forklifts |
| ICC Certification | Tested to 2021 & 2018 IBC & IRC standards |
| Min Deck height | As low as 6" |


Engineered smart. Built tougher.

Jerry & Sierra (Site Built Sheds)
“TuffBlocks have turned building the deck foundation - once one of the hardest, most labor-intensive parts - into a quick, easy process.”

Russell (Shedscape)
“TuffBlocks let us build perfectly level shed foundations on sloping yards - faster, cleaner, and more professional than concrete.”

Justin (DIY)
"Strong, easy to use, and helped save me tons of time and energy building the frame of our deck!"
TUFFBLOCK CALCULATOR
how many Tuffblocks do I need?
Enter your dimensions - we'll calculate your packs.
✔ Based on 16" on-center spacing
✔ Calculation based on ground-level decks
Common Deck & Shed Sizes
| Deck Length (feet) | Deck Width (feet) | Deck Area (sq feet) | Estimated TuffBlocks |
|---|---|---|---|
| 8 | 12 | 96 | 24 |
| 20 | 10 | 200 | 42 |
| 20 | 12 | 240 | 42 |
| 30 | 10 | 300 | 60 |
| 20 | 16 | 320 | 56 |
| 35 | 10 | 350 | 72 |
We Had TuffBlocks Independently
Tested to Destruction.
How to Install TuffBlocks in 3 Simple Steps
1Prepare Your GROUND
Remove loose topsoil or vegetation. Compact the ground. Add crushed rock or paver base for extra stability.
2Place & Level TuffBlocks
Position blocks on your prepared surface. The wide base and smart geometry distribute load evenly.
3Build Your Frame & Deck
Install joists or posts into TuffBlock slots and begin building immediately. No waiting. No curing. Start today.
CODE COMPLIANCE: TuffBlock is suitable for decks that are not attached to your home, or structures less than 40" above grade.
ICC CERTIFIED
Inspector-Ready
Documentation
TuffBlock has been assessed by the International Code Council and is shown to be compliant with the following:
2021 & 2018 International Building Code (IBC)
2021 & 2018 International Residential Code (IRC)
California (LABC/LARC/CBC), Florida Building Code and more.
Always verify with your local authority.
Built for Real-World Conditions
Frost heave
Sits on compacted gravel, allowing natural ground movement without cracking like in-ground concrete footings.
Sinking
Wide base spreads load evenly. On compacted gravel, TuffBlocks create a stable, long-term foundation.
High Wind
Combine with earth anchors or in-ground footings at perimeter points for high-wind and storm-prone areas.
Sloped Ground
TuffBlocks can be leveled independently across your site, with posts cut to different lengths as needed.
25
Years Warranty
150K+
Builds Across North America
0
Warranty Claims
Decks, Sheds & More Built With TuffBlock
Click on any of the below to see real decks, sheds, stairs and more built using BuildTuff's TuffBlock foundation blocks.







- Won’t crack, chip or corrode like concrete
- UV-stabilized for long-term outdoor use
- Made from high-strength recycled polyolefin
- Ventilated underside prevents moisture build-up
- Designed to deter termites & protect lumber
- Works on uneven terrain, grass, soil, or concrete
Contractor & DIY Review
Site Built Sheds (Charlotte, NC)
Jerry from Site Built Sheds uses TuffBlocks on every job because they’re faster, lighter, and more reliable than concrete.
Justin & Jess DIY (Nashville, Tennessee)
“As a first-time DIYer, TuffBlocks were a game-changer. They made the whole deck project simple and straightforward.”
Built for the Jobsite
Forget hauling heavy blocks or waiting days for concrete to cure.
With TuffBlock, you can:
Cut install times in half — crews can frame the same day.
Keep overhead low — reduce transport costs and back-breaking labor.
Work anywhere — on uneven soil, turf, or pavers with a little leveling.
Deliver lasting builds — backed by a rock-solid 25-year warranty.
- Cut install times in half — crews can frame the same day.
- Keep overhead low — reduce transport costs and back-breaking labor.
- Work anywhere — on uneven soil, turf, or pavers with a little leveling.
- Deliver lasting builds — backed by a rock-solid 25-year warranty.
What others say
How to Build Easy With TuffBlocks
Drop

Place your TuffBlocks directly onto firm, level ground — grass, dirt, gravel, or even concrete. No need to dig holes or pour footings. Just space them where your posts or joists will go.
Level

Use a spirit level to make minor ground adjustments if needed. TuffBlocks work best on flat, stable surfaces — and minimal prep is all it takes. Tip: Use packers such as crusher dust underneath for extra stability and longevity.
Build

Drop in your 3.5" or 4" posts or 1½" - 2" Joists & Bearers — From here, just start building your deck, shed base, stairs, or even tiny home floor.

Frequently Asked Questions
Deck permit requirements vary by city and county, and most residential decks must meet local building code requirements.
In many areas, you will need a building permit for a deck if it:
-Is attached to your home and is more than 40" above grade.
-Exceeds a certain square footage.
-Includes stairs, railings, or a roof structure.
Some jurisdictions provide deck permit exemptions for small, freestanding or low-profile decks under a certain size. However, permit rules differ depending on your local building department. Even when us16ing deck blocks instead of concrete footings, your deck must still meet structural and safety requirements set by your local building inspector.
If you live in a wildfire-prone area, coastal zone, or high-wind region, additional deck-building code requirements may apply. Because deck permit requirements vary nationwide, always contact your local building department before starting your project to confirm permit and inspection requirements.
TuffBlocks have been engineered for structures up to 36" above ground. Having said this, many people have built structures higher than this using the composite foundation method (TuffBlocks in combination with concrete-in-ground footings). We recommend that you consult with a qualified builder or engineer regarding your project.
Yes, you can use TuffBlocks in high wind areas (Cyclones, Hurricanes, Storms etc), but we recommend checking in with your local building authority first. Some users choose to use earth anchors to help secure their structure, while others opt for an intermediary solution by combining TuffBlocks with in-ground concrete footings for additional stability.
TuffBlock uses a floating foundation system designed to let your structure move slightly with natural ground movement. This prevents the stress and cracking you often see in fixed, concrete-in-ground foundations.
The system was originally created for regions with extreme freeze–thaw cycles, where:The ground becomes too hard to dig, and Traditional fixed footings fail because they can’t flex with seasonal expansion and contraction.
By “floating” instead of being locked into the ground, TuffBlock keeps your deck or structure safer, more stable, and longer-lasting.
This is exactly where the Floating Foundation System was developed for areas in the north (USA) where freeze and thaw ground movement is a major issue for traditional "dig a hole and pour concrete" structures. So TuffBlock is a perfect solution for their application.
Yes, simply level the ground under each TuffBlock. Then level the structure above using extension posts supported by the pocket of the TuffBlock below. Refer to the installation guide for more detail. Alternatively, if the impenetrable surface is sloping at a severe angle, it may be worth considering using an alternative support/footing/foundation.
For most ground-level floating decks, TuffBlock support rows should be spaced no more than 60 inches (5 feet) apart center-to-center. For standard builds using 16-inch on-center joist spacing, place a TuffBlock at the start, middle, and end of each joist run.
Spacing may vary depending on joist size, lumber species, and total load. You may need additional blocks if your deck includes stairs, multiple tiers, or an irregular layout.For deck overhangs beyond the last support row, place a TuffBlock no more than 12 inches from the end of the build to maintain structural stability.
Use the TuffBlock calculator above to estimate how many blocks you need. Always check local building codes before starting your project.
Yes - TuffBlock is used on thousands of shed builds across the US every year. It works on soil, gravel, concrete, and sloped ground, and keeps your timber floor off the ground to prevent rot. For sizing, spacing, permits, and step-by-step instructions, see our complete shed foundation guide →
0:00 What is a floating foundation system?
0:31 How much weight can each TuffBlock support?
0:43 Are TuffBlocks UV resistant?
0:58 Can I use TuffBlocks on sloping ground?
1:14 Do I need council approval?
1:34 How do posts/joists sit in the TuffBlock and do they require fixing?
1:56 Can TuffBlocks be used on wet surfaces?
2:22 Can I use TuffBlocks on sand?
2:35 Will TuffBlocks sink into the ground?
3:08 Can I use TuffBlocks in high wind areas?
3:27 How many TuffBlocks will I need for my project?
3:57 What if I have ground movement in my area?
0:00 What is a floating foundation system?
0:31 How much weight can each TuffBlock support?
0:43 Are TuffBlocks UV resistant?
0:58 Can I use TuffBlocks on sloping ground?
1:14 Do I need council approval?
1:34 How do posts/joists sit in the TuffBlock and do they require fixing?
1:56 Can TuffBlocks be used on wet surfaces?
2:22 Can I use TuffBlocks on sand?
2:35 Will TuffBlocks sink into the ground?
3:08 Can I use TuffBlocks in high wind areas?
3:27 How many TuffBlocks will I need for my project?
3:57 What if I have ground movement in my area?
Please note. This FAQ video relates to both the TuffBlock and Evo-Crete Handi Block products. BuildTuff offers this information as a general guide only. You should rely only on relevant building codes and standard industry established construction methods in any construction project. For our Master FAQ, please click here.


