Log Cabin Bases
Poured to manufacturer spec.
150mm C28/35 with A142 mesh, the spec every reputable log cabin manufacturer asks for. Delivered ready-to-pour, warranty-valid paperwork with every ticket.
The Mix You Need
C28/35 Reinforced Slab
- Mix grade
- C28/35
- Slump
- 75mm
- Aggregate
- 20mm
- Recommended depth
- 125-150mm
- Reinforcement
- A142 mesh recommended
- Sub-base
- 150mm Type 1 MOT
Volume Guide
How much concrete for your cabin?
Volumes assume 150mm depth. Always go to your manufacturer's specified footprint + 100mm on each side.
Small cabin (3×3m)
3.0m × 3.0m
150mm depth
Medium cabin (4×4m)
4.0m × 4.0m
150mm depth
Large cabin (5×5m)
5.0m × 5.0m
150mm depth
Twin-room cabin (6×4m)
6.0m × 4.0m
150mm depth
Why It Matters
Get this right and you won't redo it for 30 years
- Log cabins are heavy, solid timber walls, heavy roof systems, insulation and furniture can easily top 4 tonnes. The base must be rated for it.
- 150mm C28/35 with A142 mesh is the recognised spec for domestic log cabins and it costs less than re-laying a failed slab in 5 years.
- Cabins are sensitive to movement, even a 5mm differential settlement can cause logs to bind and doors to stick. A proper base prevents this.
- Most log cabin manufacturers require photographic evidence of the base to honour the warranty. Ready-mix with a delivery ticket gives you that paper trail.
Step by Step
How to prepare & pour
Check manufacturer's base spec
Every log cabin supplier publishes a base requirement. Go to the higher of theirs or ours, typically 150mm of C28/35 with A142 mesh. Larger cabins (30m²+) may need 175mm.
Excavate 300mm deep
Dig to 300mm below finished level (150mm sub-base + 150mm slab). Extend the excavation 100mm beyond the cabin footprint on every side.
Compact Type 1
150mm of Type 1 MOT in 50mm compacted layers. The top surface must be level and ring solid, shortcuts here translate to cracks in the slab.
DPM & formwork
1200-gauge DPM over the sub-base, 150mm overlap on joints. Formwork set to finished slab level. Check level with a 2m straightedge, not by eye.
A142 mesh on spacers
Lay A142 mesh on 50mm plastic spacers. Overlap sheets by 300mm and tie with wire. The mesh should sit in the lower third of the slab.
Pour & finish
Pour direct from the chute. Tamp to remove air pockets, screed to level with the straightedge, then float smooth. Cover with plastic for 24 hours if it's hot or frosty.
FAQ
Common questions
Is 100mm enough for a log cabin?
No. 150mm is the standard. Log cabins are 2-3× heavier than a shed of the same footprint. 100mm risks cracking under point loads (corner posts, stove bases) and voids the cabin warranty.
Do I need reinforcement mesh?
Yes, A142 is recommended for every log cabin over ~9m². It reduces crack propagation under cyclical loading (people, furniture, heating cycles) and gives the slab long-term integrity.
How long before installation?
14 days is ideal for a log cabin. Walk-on at 24 hours, structural at 7 days, fully cured at 28 days. Most suppliers book installation for 2 weeks after pour.
What mix for my log cabin base?
C28/35. This is a high-strength mix that'll handle the point loads from corner posts and the overall weight of a log cabin. Our shed base concrete page has the full spec.
How much concrete do I need?
Length × width × 0.15 for a 150mm slab. A 4×4m cabin base = 4 × 4 × 0.15 = 2.4m³. Order with 10% wastage, our calculator handles this automatically.
Can I pour the base myself?
The prep work (dig, sub-base, formwork, mesh) is DIY-able. The pour itself benefits from ready-mix, a log cabin base is 2-4m³ which is far more than you'd realistically mix by hand.
Ready to order?
Instant price in 60 seconds. Next-day delivery subject to availability. With volumetric, pay only for what's poured.