What Thickness Should a Concrete Shed Slab Be?
A concrete shed slab should be 100mm (4 inches) thick for standard garden sheds and light storage applications. However, thickness requirements increase based on your intended use.
Standard Shed Slabs:
- 100mm thickness: Garden sheds, storage units, light equipment
- SL72 mesh reinforcement minimum
- Suitable for foot traffic and standard storage
Heavy-Duty Shed Slabs:
- 125-150mm thickness: Workshops with machinery, vehicle storage, garages
- Increased reinforcement (SL82 or N12 rebar)
- Necessary for cars, trailers, and heavy equipment
Thickened Edge Requirements:
- Edge beams are typically 200-250mm deep
- Provides structural support and prevents edge cracking
- Required for all shed slabs in Hobart
All shed slabs must be constructed on a properly compacted crushed rock base (100-150mm depth) and comply with Australian Standard AS 2870 for residential slabs and footings. The right thickness depends on what you’re storing and how you’re using the space – not every shed needs a heavy-duty slab, but cutting thickness on a garage or workshop will cost you more in repairs down the track.
Types of Shed Slabs We Install Across Hobart
Our Shed Slab Construction Process
Site Assessment and Ground Preparation: Free on-site measurement throughout Greater Hobart. Slope analysis for hilly terrain, site clearing, excavation to the required depth, and underground service identification before we start.
Base Layer and Drainage Installation: 100-150mm crushed rock mechanically compacted to 95% density. Agricultural pipe installation around the perimeter handles Hobart’s 600mm+ annual rainfall and prevents ground moisture problems.
Formwork, Reinforcement and Vapour Barrier: Laser-levelled timber or steel boxing with SL72 mesh (or SL82/N12 rebar for heavy-duty). 200-micron polyethylene vapour barrier and 200-250mm deep thickened edge beams for structural support.
Concrete Pouring and Finishing: N25 or N32 grade concrete with screed levelling to ±5mm tolerance. Choice of broom texture, smooth trowel, or plain finish with integrated falls for drainage.
Project Timeline: Site preparation and formwork: 2 days. Concrete pour and finishing: 1 day. Curing period: 3-7 days before shed installation. Total timeframe: 3-5 days plus curing, weather dependent.
Hobart Site Challenges and Council Requirements
Managing Sloped Terrain and Difficult Access: Cut and fill earthworks for level placement on hills. Retaining wall integration where needed. Concrete pump usage for narrow side access.
Drainage Solutions for Hobart’s High Rainfall: Integration with existing drainage systems designed for 600mm+ annual rainfall.
Clay and Reactive Soil Management: Proper base preparation for expansive clay soils common in Hobart. Adequate slab thickness and reinforcement for soil movement resistance.
Hobart City Council Regulations: Sheds under 10m² are typically exempt from planning permits. Setback requirements: 900mm from side boundaries, 4.5m from front. Heritage area considerations in Battery Point and Salamanca, if applicable.
Building Standards Compliance: Tasmanian Building Standards requirements and WorkSafe Tasmania site safety compliance are documented with every project.
Why a Quality Shed Slab Foundation Is Essential
Protection from Tasmania’s Climate: Moisture barrier prevents groundwater ingress in high-rainfall conditions. Elevation above ground level for drainage.
Level Surface for Easy Shed Assembly: Professional slab tolerances of ±5mm over 3 meters mean proper door and window alignment. Prevents structural stress and warping.
Long-Term Structural Stability: Prevents differential settlement and cracking. Distributes shed loads evenly with anchoring points for wind resistance.
Moisture and Pest Protection: Keeps stored items dry in Tasmania’s high humidity. Prevents rust on tools and machinery.
Vehicle and Equipment Functionality: Smooth surface for easy maneuvering of cars, trailers, and machinery. Load-bearing capacity for heavy equipment.
Shed Slab Costs and Investment Value in Hobart
Pricing Factors for Your Shed Slab: Slab size from 3m x 3m to 6m x 9m, site preparation requirements, access considerations, thickness specifications, reinforcement upgrades, and finishing choices all affect your final price.
Site-Specific Cost Variables: Level sites require minimal preparation with lower costs. Sloped sites need cut and fill earthworks. Difficult access may require concrete pump hire.
What’s Included in Our Shed Slab Price: Complete site assessment, all excavation and ground preparation, crushed rock base and compaction, formwork and reinforcement, vapour barrier, concrete supply and placement, professional finishing, and compliance documentation.
Long-Term Value and Return on Investment: One-time investment with 40+ year lifespan protects shed structure from moisture damage and movement.
Transparent Quoting Process: Free on-site quotes throughout Greater Hobart with detailed cost breakdowns. No hidden fees or surprise charges.
Frequently Asked Questions About Shed Slabs in Hobart
We recommend waiting 3-7 days before installing your shed, depending on weather conditions. The concrete reaches about 70% strength in 7 days, which is enough for shed installation. However, full curing takes 28 days. We’ll give you the exact timeline based on the season and forecast when we complete your pour.
Sheds under 10m² floor area typically don’t require a planning permit in Hobart. However, you still need to meet setback requirements – 900mm from side boundaries and 4.5m from the front boundary. Heritage areas like Battery Point and Salamanca have additional restrictions. We’ll check your specific property during our site assessment and let you know what’s required.
Yes, we handle sloped sites all the time across Hobart – it’s one of our specialties, given the terrain in areas like Mount Nelson and Sandy Bay. We do cut and fill earthworks to create a level base, and sometimes integrate retaining walls if the slope is significant. The steeper the site, the more preparation work is involved, but we’ve completed shed slabs on some very challenging Hobart properties.
Shed slabs are generally simpler and less expensive than house slabs. They’re typically 100-150mm thick compared to house slabs that often need to be thicker with more complex reinforcement. Shed slabs don’t require the same level of insulation, plumbing integration, or internal beams that house slabs need. However, they still need proper base preparation, drainage, and reinforcement to perform correctly for decades.
A basic 3m x 3m garden shed slab typically starts around $1,500-$2,500, while a 6m x 9m double garage slab runs $6,000-$10,000+. The final cost depends on your site conditions, access, thickness requirements, and finish choices. Level sites with good access cost less than sloped properties that need earthworks and concrete pumping. We provide detailed quotes after assessing your specific property.
Some minor hairline cracks are normal in concrete as it cures and adjusts to seasonal temperature changes. However, structural cracking shouldn’t happen if the slab is properly constructed. We prevent cracking by using proper base preparation, adequate reinforcement, correct concrete grade, and appropriate thickness for your application. Our shed slabs are built to last 40+ years without significant cracking or structural issues.
Ready for a Professional Shed Slab in Hobart?
Get a free, no-obligation quote for your shed slab project. We’ll assess your site, discuss your requirements, and provide transparent pricing for your specific needs. Serving all Greater Hobart areas, including Sandy Bay, Mount Nelson, Battery Point, Kingston, Glenorchy, Clarence, and surrounding suburbs.
Contact Concrete Power Hobart Today:
Phone: 0361706070
Email: info@concretehobart.com.au
Business Hours: Monday-Friday, 7 am-5 pm
