Introduction
In concrete formwork systems, the choice between H20 timber beams and solid timber beams is critical for project cost, speed, and quality. While both have been used for decades, modern construction increasingly favors H20 beams for slab and wall formwork.
In this guide, Linyi Solland International Trade Co., Ltd. compares these two beam types so you can choose the right one for your project.
What Is an H20 Timber Beam?
The H20 timber beam is an engineered wood I-beam designed specifically for concrete formwork. It consists of:
- Top and bottom flanges: Solid wood (typically spruce or pine), finger-jointed and glued
- Web: 24mm–27mm plywood (poplar or birch)
- End protection: Plastic or metal end caps
- Surface: Yellow or clear phenolic coating
Standard dimensions:
- Depth: 200mm (8 inches)
- Width: 80mm (3.15 inches)
- Length: 1.95m–5.9m (custom lengths available)
- Weight: 4.5–5.5 kg/m
Standard designation: H20 in EN 13377 (European standard for formwork beams)
What Is a Solid Timber Beam?
A solid timber beam is a traditional solid wood beam cut from a single piece of softwood (typically pine, spruce, or fir).
Standard dimensions:
- Cross-section: 80mm × 200mm, 100mm × 200mm, 120mm × 240mm
- Length: 2m–6m
- Weight: 8–15 kg/m (heavier than H20)
No standardized designation — varies by region and supplier.
H20 vs Solid Timber Beam: Quick Comparison
| Feature | H20 Timber Beam | Solid Timber Beam |
|---|---|---|
| Type | Engineered I-beam | Solid sawn wood |
| Weight (per meter) | 4.5–5.5 kg/m | 8–15 kg/m |
| Bending strength | 5.0 kN·m | 3.5–4.5 kN·m |
| Shear strength | 11.0 kN | 8–10 kN |
| Stiffness (EI) | 450 kN·m² | 350–400 kN·m² |
| Reuse cycles | 30–50+ | 8–15 |
| Deflection | Lower | Higher |
| Standardization | EN 13377 | None |
| Cost (per meter) | $4–$8 | $3–$6 |
| Cost per use cycle | $0.10–$0.20 | $0.30–$0.50 |
| Quality consistency | High | Variable |
| Length options | Custom up to 12m | Limited |
| Best for | Modern slab formwork | Simple residential |
Detailed Performance Comparison
1. Strength and Load Capacity
H20 beams are engineered for higher load capacity with lower weight:
- Bending moment: 5.0 kN·m (vs 3.5–4.5 kN·m for solid)
- Shear force: 11 kN (vs 8–10 kN for solid)
- Stiffness: 450 kN·m² (vs 350–400 kN·m² for solid)
For a typical slab formwork with 2.5m primary beam span, H20 beams can support 50% more load than comparable solid timber beams.
2. Weight Savings
H20 beams are 40–60% lighter than solid timber beams:
- H20 beam: 4.5–5.5 kg/m
- Solid timber beam (80×200mm): ~11 kg/m
This weight savings translates to:
- ✅ Faster installation — workers handle lighter beams
- ✅ Lower labor cost — fewer workers needed
- ✅ Easier transportation — more meters per container
- ✅ Reduced structural load — less weight on shores
3. Reuse Cycles
This is where H20 beams dramatically outperform solid timber:
| Beam Type | Typical Reuse Cycles | With Proper Care |
|---|---|---|
| H20 beam | 30–50 cycles | 50–80 cycles |
| Solid timber beam | 8–15 cycles | 15–25 cycles |
H20 beams last 3–5x longer because:
- Plywood web doesn't crack along grain
- Finger-jointed flanges resist splitting
- Phenolic coating protects against moisture
- Standardized quality control
4. Deflection and Concrete Finish
Because H20 beams have higher stiffness, they deflect less under load:
- H20 deflection (typical slab): 5–8mm
- Solid timber deflection (typical slab): 10–15mm
Less deflection means better concrete finish — fewer cracks, smoother surface, less remedial work.
5. Cost Analysis
Initial Cost
| Beam Type | Cost per meter | Cost per 5.9m beam |
|---|---|---|
| H20 beam | $4–$8 | $24–$47 |
| Solid timber beam (80×200mm) | $3–$6 | $18–$35 |
H20 beams cost 30%–50% more upfront.
Total Cost of Ownership
For a 1,000 m² slab project requiring 200 beams × 5.9m:
| Cost Item | H20 Beam | Solid Timber Beam |
|---|---|---|
| Initial purchase | $5,600 | $4,000 |
| Reuse cycles | 30 | 10 |
| Replacement cost (over 30 cycles) | $0 | $8,000 |
| Labor cost (faster install) | $4,000 | $6,000 |
| Concrete finish repair | $1,000 | $3,000 |
| Total over 30 cycles | $10,600 | $21,000 |
H20 beams save 50% over the project's lifetime.
6. Standardization and Quality
H20 beams are manufactured to EN 13377 (European standard for formwork beams) with strict quality control:
- ✅ Bending strength tested on every batch
- ✅ Shear strength tested
- ✅ Glue bond tested (boil test)
- ✅ Dimensional accuracy ±2mm
- ✅ Tracked from raw material to finished beam
Solid timber beams have no standardized quality control:
- ⚠️ Variable wood quality (knots, grain, moisture)
- ⚠️ Dimensions vary by ±5–10mm
- ⚠️ Strength varies by tree species
- ⚠️ No batch testing
For commercial projects requiring engineered formwork, H20 is the only choice.
7. Custom Lengths
H20 beams can be custom-cut to any length up to 12 meters without sacrificing strength (thanks to plywood web).
Solid timber beams are limited by sawn timber length (typically 6m max) and any joints drastically reduce strength.
For long-span slabs, beams, or irregular shapes, H20 is the only practical option.
