Renovation Lecture by Shoyan

Introduction

• Shoyan is a carpenter based in Japan.
• Current project: Renovating a Japanese-style room by replacing tatami mats with wooden flooring and renovating the engawa (veranda).
• Aim: Create a single room with more space by removing sliding screens (fusuma) and thresholds.

Common Renovation Practices in Japanese Rooms

• Common renovations include:
  • Plastering walls
  • Replacing ceilings
  • Replacing tatami mats.
• Trend: Decreasing number of tatami rooms.

Process of Renovation

1. Removing Floorboards

   • New floor will match the height of the threshold.
   • Inspect joists for rot and damage (no damage found in this case).

2. Old vs New Materials

   • Historical use of timber (non-square) instead of modern square sleepers and joists.
   • "Taiko" timber was previously used, providing durability even without a core.
   • Original wood was durable and not rotten.
   • Replaced loose wooden posts with plastic posts to prevent termite damage.

3. Old Wood Strength

   • Old wood (40-50 years) can show increased strength over time due to drying.
   • Concrete foundations also strengthen over time.

Building the Frame

• Used the same timber as the ceiling (nobuchi) to build the frame.
• Custom shims made for proper fit (2.5 mm thickness).
• Installed 30 mm Styrofoam insulation between joists for improved efficiency.

Engawa Area

• Original flooring not removed since it was undamaged.
• New floorboards installed over secured original flooring.

Floorboard Installation

• Strategy: Use 4-meter (13' 1 1/2") boards for most of the area.
• Staggered placement for sections where boards won’t reach (90 cm area).
• Sort boards by color: light sapwood vs. dark planks with knots.
  • Challenges noted with matching colors and ensuring fit with old pillars.

Challenges in Installation

• Installing the first floorboard is critical; deemed half the job.
• Process:
  1. Measure warp of the threshold.
  2. Temporarily place remaining boards for color balance.
  3. Scribe and adjust for height differences between engawa and joists.

Final Touches

• Caulk gaps between windows and floorboards to prevent water seepage.
• Protect baseboards and pillars with masking tape before oiling.
  • Use of "Gloss Clear Oil" for finishing, requires careful disposal of cloths due to flammability.
• Oil application process:
  • Generous application followed by wiping and polishing.
  • Importance of timing for the oil to prevent hardening.

Conclusion

• Successfully completed renovation by expanding the space and modernizing the flooring.
• Demonstrated techniques show adaptability in maintaining traditional structures while improving functionality.