Understanding Wood Types for Rental Property Repairs in Japan
Wood purchasing in Japan can be confusing if you learned DIY from American or European resources. The sizing conventions are different, the wood species are different, and the lumber yards often assume you already know what you’re looking for. After years of buying the wrong materials for repair jobs, I’ve put together a practical guide for landlords working in Japan.
Japanese Lumber Sizing: What the Numbers Mean
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In Japan, dimensional lumber is sold in metric sizes, but many common sizes trace back to traditional Japanese measurements. The most important sizes to know:
- 1×4 equivalent (u30efu30f3u30d0u30a4u30d5u30a9u30fc / 1u00d74): 19mm u00d7 89mm in Japan. This is one of the most useful sizes for landlord repairs u2014 shelving, simple framing additions, baseboard replacement, and general carpentry. Sold at every Cainz and Konan in lengths from 1.8m to 3.6m. SPF (spruce-pine-fir) is the standard species, running u00a5400u2013u00a5700 per 1.8m length.
- 2×4 equivalent (u30c4u30fcu30d0u30a4u30d5u30a9u30fc / 2u00d74): 38mm u00d7 89mm. Used in platform frame construction (2u00d74 construction is common in Japanese apartments built since the 1980s). For landlord repairs, you’ll use this for blocking, simple wall framing additions, and structural repairs.
- Kokusan lumber (u56fdu7523u6750): Domestic Japanese species. Cedar (sugi, u6749) and cypress (hinoki, u6a9c) are the most common. Sugi is softer and cheaper (u00a5300u2013u00a5600 per meter for 105mm square stock); hinoki is harder, more fragrant, and used in higher-quality applications. Both are widely available at lumber sections of larger Konan and Cainz stores.
Sheet Goods: Plywood, MDF, and Particleboard
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Sheet goods u2014 sold in 910mm u00d7 1820mm (3u00d76 shaku, abbreviated as u4e09u516du5224) or 1220mm u00d7 2430mm sizes u2014 are the workhorses of rental property repair. Understanding which one to use for which application saves money and avoids callbacks.
- Structural plywood (u69cbu9020u7528u5408u677f): Made from alternating wood veneers glued with the grain perpendicular. Strong, moisture-resistant (rated for exterior use), and dimensionally stable. Use for subfloor repairs, wall sheathing, and any structural application. Available in 9mm, 12mm, and 24mm thicknesses. A 12mm sheet runs u00a52,000u2013u00a53,000 at Cainz.
- Lauan plywood (u30e9u30efu30f3u5408u677f): Made from Southeast Asian hardwood, lauan is smooth-surfaced and paintable. Good for interior wall panels, drawer bottoms, and decorative applications. Not suitable for outdoor or high-moisture environments. A 5.5mm sheet costs u00a51,500u2013u00a52,500.
- MDF (u4e2du5bc6u5ea6u7e4au7dadu677f): Medium-density fiberboard is made from compressed wood fiber. Extremely smooth surface, machines beautifully, and accepts paint evenly. The downside: it swells dramatically when exposed to water and is heavy. Use it for interior shelving, door panels, and furniture repairs where moisture isn’t a concern. A 9mm sheet runs u00a51,800u2013u00a52,800.
- Particleboard (u30d1u30fcu30c6u30a3u30afu30ebu30dcu30fcu30c9): The cheapest sheet good, used in budget furniture and subfloor applications. Heavy, not durable in moisture, and hard to fasten securely with screws near edges. I use it only when replacing existing particleboard components and budget is the primary concern.
Hardwoods vs. Softwoods in Japanese Rentals
Most Japanese residential construction uses softwoods for framing and interior trim. Hardwoods appear in flooring, countertops, and decorative elements. Understanding this division helps you buy the right material for each repair.
- Softwoods (u91ddu8449u6a39): Cedar (sugi), cypress (hinoki), pine (matsu), and imported SPF fall here. Used for framing, trim, shelving, and general carpentry. Easy to work with hand and power tools, readily accepts paint and stain.
- Hardwoods (u5e83u8449u6a39): Oak (nara), cherry (sakura), walnut (kurumi), and teak appear in flooring and furniture. When replacing flooring sections, matching the hardness and grain pattern of the existing floor is important u2014 harder woods resist foot traffic better but are harder to cut and finish.
Where to Buy and What to Expect to Pay
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For standard dimensional lumber and sheet goods, Cainz and Konan are the easiest options u2014 wide selection, competitive pricing, and most locations have a cutting service that reduces planks and sheets to your dimensions for a small fee (typically u00a550u2013u00a5100 per cut). This is worth using if you don’t have a proper cutting area at your property.
For premium domestic lumber (hinoki, nara hardwood flooring, etc.), specialized lumber yards (u6750u6728u5c4b) carry better stock and can help you match existing flooring grain and color. These aren’t as accessible as big-box stores, but the staff knowledge is invaluable when you’re trying to match 30-year-old cedar trim. MonotaRO is a good source for hardware fasteners and specialty items, but not for bulk lumber.
Learning the material differences early saves real money. Buying MDF for a bathroom repair, or standard plywood where you needed structural-grade, leads to failures that cost more to fix than the original repair.
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15 years of landlord experience u00b7 3 apartment buildings u00b7 DIY renovations that saved millions of yen. Browse all articles at diytosan.com
