Wall production and repair - 2

While painting or wallpapering walls is a familiar DIY task around the world, this article focuses on traditional wall finishing methods unique to Japanese architecture.

A Note Before You Start

Did you buy your house, or are you renting it? If you're renting, be sure to check your lease and get your landlord’s permission before redecorating. In Japan, making changes like repainting or re-wallpapering without approval is often considered a breach of contract. Even if the end result looks better than before, tenants may still be charged a restoration fee―or even lose their deposit.

Some rental contracts are so strict that even putting a thumbtack in the wall can lead to deductions from your deposit. Because of this, many renters in Japan use removable interior solutions, like temporary walls built in front of the existing ones. You’ll often find DIY kits and brackets specifically made for this purpose using standard 2x4 lumber. It may sound like a joke, but it’s a real and common solution.

In Japan today, interest in renovating older homes is growing. Renters face strict restrictions, and rising housing prices combined with stagnant wages have made building a new home difficult. Some people take out 50-year loans, committing to debt well into old age just to afford a newly built house.

Renovating an older home can be a more realistic―and creative―option. Although older properties may have concerns around earthquake resistance and long-term durability, they offer the freedom to create a living space that reflects your own style.

While many professional renovations try to make old homes look brand new, this article explores DIY methods that preserve the unique beauty of traditional Japanese clay walls.

Older Japanese homes often feature a variety of wall finishes. Below are some of the most common materials and how to work with them:

Clay Wall (Tsuchi-kabe)

Made from clay soil mixed with hemp or straw, these walls are sometimes left bare in attics, storehouses, or servant quarters to reduce construction costs. In older times, bare clay walls were seen as cheap or unfinished. However, today they are considered a luxury feature due to the time and skill required to create them.

You can clean and re-coat clay walls with new finishing materials if they are in good condition. They often have cracks, which are fine if you’re using a thick finish like plaster. But if you plan to paint them, you'll need to fill the cracks first.

Leaving clay walls bare gives a natural look but comes with downsides: they’re fragile and prone to shedding dust. You can apply a special sealer to improve durability, but this cancels out the clay's natural ability to control humidity.

Plaster (Shikkui)

Plaster is a traditional finish used for both interior and exterior walls. Western-style plaster is mixed with sand, marble powder, and applied thickly for strength. Japanese plaster, in contrast, is made from slaked lime mixed with seaweed glue and plant fibers, and is applied in a thinner coat.

While originally popular for its water resistance, plaster is now mostly used indoors. It can be tinted in colors like black, red, or indigo. If the existing plaster is in good shape, you may be able to coat over it. However, if it’s peeling or damaged, it’s best to remove the old layer before reapplying.

Juraku Wall (Juraku-kabe)

Dating back to the 1580s, Juraku walls are made with a special sandy clay that gives them a rougher texture than standard clay walls. Once considered a refined material for tea rooms and high-end buildings, true Juraku clay is now hard to find. Most modern “Juraku-style” walls use clay or sand mixed with resin to replicate the look.

Sand Wall (Suna-kabe)

Introduced in the 1950s, sand walls are made by hardening crushed shell or sand with glue. They offer a texture similar to Juraku walls and are still used in Japanese-style rooms.

However, they’re fragile and crumble easily. Many people dislike them because old sand walls often shed sand with a simple touch. In humid areas, they can also mold, as moisture tends to stay on the surface. When renovating, you can either remove the sand wall completely or seal it and apply a new finish on top.

Fiber Wall (Seni-kabe or Wata-kabe)

Also popularized in the 1950s, fiber walls are made by mixing plant or chemical fibers, paper, wood powder, and glue. Softer and warmer in appearance than plaster, they were widely used due to low cost and easy application. A shiny version with cotton known as “cotton wall (Wata-kabe)” is often found in older homes.

Though still sold today and suitable for DIY projects, fiber walls have poor durability. Many peel easily due to age and dried-out glue. Like sand walls, they also carry an “old-fashioned” image that some people find unappealing.

Fiber walls can be removed by lightly spraying with water. Special products using absorbent polymers can also help. Once removed, you can apply plaster or another finish, or seal the existing fiber wall and apply a new material on top.

Wallpaper

Wallpaper became popular in Japan in the 1960s. In many older homes, wallpaper has been applied directly over clay walls sealed during previous renovations.

To wallpaper over a clay wall, you must smooth and harden the surface with a sealer―this is time-consuming and often ruins the natural feel of a Japanese-style room. If you want to go from wallpaper back to plaster or clay, it can be difficult to remove due to the hardened sealer. Wetting the wallpaper and letting it sit briefly can sometimes help, but risks damaging the clay underneath.

Diatomaceous Earth (Keisoudo)

A more recent trend, diatomaceous earth is made from fossilized plankton. It’s praised for its ability to regulate humidity, deodorize, insulate heat, and resist fire. It’s also easy to apply as a DIY project.

However, applying it over sealed clay walls doesn’t give you much added benefit. It’s also not water-resistant like plaster, so it may stain or grow mold in humid areas. While great for beginners, it’s hard to get a clean, professional-looking finish.