ud83dudcda Wood Deck Build Log u2014 14 of 45
u2190 Structural Design Pt.2: Deck Board Fastening u00b7 Series Index u00b7 Structural Design Pt.4: Finalizing Materials u2192
→ See the complete Wood Deck DIY Guide
2026 Note from DIY Dad: Structural Design Overview
ud83duded2 RECOMMENDED PRODUCTS
Pressure-Treated Deck Lumber
Pressure-treated lumber is the baseline u2014 skip it and you’ll be rebuilding in 5 years.
Once the materials were chosen, the next step is structural design — deciding what structure to build, how the roof interfaces with the building, and what to do about railings.
Basic Structure of a Wood Deck
ud83duded2 RECOMMENDED PRODUCTS
Deck Stains & Waterproof Sealers
Stain every 2u20133 years. It’s the single cheapest way to double deck lifespan.
- Footing (束石): placed on the ground as a foundation
- Post (束柱): stands on the footing
- Beam (大引き): laid across the posts along the long axis
- Floor joist (根太): laid across the beams, supporting the decking
- Decking board: surface material fastened to the joists
I chose a free-standing roof structure and a fence-style railing using the same decking board material for a consistent look.
Originally published: 2017-05-29. Continuing the roof material investigation — I looked at attaching polycarbonate corrugated roofing to Super Light 700 purlins using a pipe bolt set:
↑ Pipe bolt set
Assembly concept sketch:
↑ Pipe bolt assembly concept
No structural issues — but one concern. Corrugated roofing has no structural strength of its own; all strength must come from the substrate. That means the substrate pitch must be tight — typically around 500 mm:
↑ Substrate pitch for corrugated roofing
That means a large number of Super Light 700 members. The whole point of Super Light 700 is that its high strength lets you use fewer members — increasing the count defeats the purpose. On top of that, the pipe bolt sets also need to be at a tight pitch — about every 5 corrugation ridges:
↑ Pipe bolt pitch
I would need roughly 450 pipe bolts. At ¥288 for a pack of 10: 450/10 × 288 = ¥12,960. That is too expensive. Corrugated roofing and Super Light 700 are a poor combination.
ud83dudcda Wood Deck Build Log u2014 14 of 45
u2190 Structural Design Pt.2: Deck Board Fastening u00b7 Series Index u00b7 Structural Design Pt.4: Finalizing Materials u2192
DIY Renovation Quote Review Manual
How to read, compare, and negotiate contractor quotes. This manual saved me u00a5800,000 on a single renovation project.
ud83cudfe0 More from DIY Father
15 years of landlord experience u00b7 3 apartment buildings u00b7 DIY renovations that saved millions of yen. Browse all articles at diytosan.com
