Apt.1 1F Japanese Room: Floor Repair Pt.2

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u270fufe0f Originally published: 2021-10-27 / ud83dudd04 Updated: May 8, 2026

2026 Update u2014 Japanese Room Floor Repair (Tatami u2192 Cushioned Flooring)

With the walls and ceiling done, it was finally time to tackle the floor. Removing the tatami and laying cushioned vinyl flooring (CF) is the finishing touch on converting a traditional Japanese room into a Western-style one.

Tatami Removal & Subfloor Inspection

Pulling out the tatami is straightforward, but checking the subfloor underneath is critical:

1. Lift and remove each tatami mat (a 6-mat room has 6u20138 mats)
2. Inspect the joists (structural floor framing) beneath
3. Any rotted or soft joists must be replaced
4. Adding rigid foam insulation (Styrofoam boards, etc.) under the floor dramatically cuts cold-floor issues
5. Squeaky or springy sections need joist reinforcement

In older apartments, you sometimes find the joists exposed right under the tatami with no sheathing at all. If the joists are in bad shape, repair them before laying CF.

Choosing the Right Cushioned Flooring (CF)

For rental renovation, look for:

• Thickness: 2.3mm or more (thinner sheets telegraph subfloor imperfections)
• Pattern: wood grain and stone grain are popular; for a Japanese room conversion, wood grain works well
• Features: antibacterial and stain-resistant versions are ideal for rentals
• Durability: residential grade is fine; commercial grade offers extra longevity

Budget guide: roughly u00a5500u2013u00a51,000 per meter at the home center. A 6-mat room (approx. 10mu00b2) comes to u00a55,000u2013u00a510,000 for materials.

CF Installation u2014 Step by Step

1. Clean the subfloor and check for high spots (patch joist-level bumps with compound)
2. Measure the room and cut the CF a bit oversized (+10u201320cm on each edge)
3. Dry-fit the CF and confirm position
4. Lay CF double-sided tape (or use dedicated CF adhesive for full-bond installation)
5. Press the CF down from the center outward, pushing out any air
6. Trim edges at walls and around columns with a floor knife and utility knife
7. Roll with a seam roller for full adhesion

The trickiest part for beginners is the wall-edge cuts. Press a floor straightedge firmly against the wall and run the utility knife along it u2014 that’s how you get a clean straight line.

Sill & Lintel Patching

The wooden frame components of the Japanese room sliding doors matter too:

• Shikii (sill/threshold): the horizontal timber at floor level with the sliding door groove
• Kamoi (lintel/head track): the matching timber above

Old sills and lintels are often scratched and dirty. Simply filling the scratches with compound and painting over them makes a noticeable difference. If the sliding door sticks, applying a sill-glide tape to the track fixes it.

The Floor Repair Completes the Conversion to a Western Room

Once the tatami-to-CF swap is done, the Japanese room becomes a proper Western-style room. What I noticed after completing this:

• Prospective tenants started saying “this feels like a livable space” much more often
• The room became especially popular with younger single tenants and couples
• The number of enquiries increased compared to when the tatami was still in
• Even with a u00a55,000u2013u00a510,000 rent increase, applications still came in

Floor + walls + ceiling u2014 once all three are done, a dated Japanese room becomes a modern Western-style space. Apt.1’s large-scale DIY renovation was gradually coming together.

ud83cudfe2 For Anyone Considering Apartment Investment & Renovation

Cost-effectiveness is everything in apartment renovation. DIY-ing the work yourself can slash costs dramatically.

• Marutoku Shop | Renovation materials & lumber online u00bb

Hi, it’s DIY Dad! After removing the tatami, the next step would normally be laying the CF underlayment u2014 but for this job I outsourced the underlayment to a contractor.

u2191 CF underlayment installed by contractor

u2191 CF underlayment

From here, I lay the cushioned flooring myself. For tool and material details see “DIY Dad’s Tools & Materials Vol.2: Cushioned Flooring Installation.”

I’m using a wood-grain CF. Here’s the process: cut the CF a few centimeters larger than the room on each side, then fold half of it back. Apply CF adhesive to the exposed subfloor, wait for the open time, then fold the CF back down and press it into place. Roll from the near edge outward to push out any air. Then fold back the other half, apply adhesive to that section, and trim the edges to fit the room shape precisely.

I’ll admit u2014 I barely took any progress photos for this step. My bad.

u2191 Cushioned flooring u2014 finished

That’s all for today. See you next time!

ud83dudd27 DIY Dad’s Recommended Tool

A cordless electric driver set that boosts efficiency for all DIY tasks. Compact and easy to handle u2014 works well for beginners and experienced DIYers alike.

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