Last updated: December 26, 2025 at 11:28 AM
Due to age-related deterioration of the unit bath in my condominium, various parts such as the shower hook, door stopper, and towel rack were damaged, so I purchased various parts from Monotaro and Amazon and replaced them with new ones.
We also spent a whole day cleaning the limescale stains on the FRP surface, and repaired the cracks in the inspection openings, so the unit bath is now so beautiful that it's hard to believe it's a 42-year-old condominium.
On a separate note, the hinge of an old wardrobe broke due to metal fatigue, so I purchased parts from Monotaro to replace it.
As years pass, many things break beyond their useful life. In particular, the service life of unit baths and system kitchens is said to be approximately 20 years, so these equipment in your condominium have long since reached the end of their service life. However, it is likely to cost at least 1.3 million yen or more to replace the entire unit bath and system kitchen, so it is not possible to replace the entire unit due to the budget.
In 2025, we incurred expenses of over 600,000 yen for replacing the air conditioner at DAIKIN, converting all rooms to LED lights, and replacing the range hood, toilet bowl, and shower/toilet, so we decided to carry out partial repairs to the condominium facilities as a unit owner while keeping costs as low as possible.
By the way, the drainage system in our condominium seems to be the old-style under-slab piping system that was often used in older condominiums. In this method, the drain pipe penetrates the floor slab (concrete floor), passes through the attic of the floor below, and is connected to the drain standpipe.
The service life of drainage standpipes varies greatly depending on the material, with hard vinyl chloride pipes having a rough lifespan of 30 to 40 years, cast iron pipes having a lifespan of 25 to 40 years, steel pipes (SGP, etc.) having a lifespan of about 15 to 30 years, and stainless steel pipes (SUS) having a lifespan of 50 years or more.
Considering the age of the building, it appears that the drainage standpipes in this condominium are cast iron pipes, but regular inspections are important after 20 years of construction, and in many condominiums, large-scale repairs (updates/rehabilitation) are considered after 30 years of construction.
Currently, there have been several incidents of water leakage from the ceiling in our condominium, and investigations and repairs are being carried out at the expense of the management association (covered by non-life insurance). According to a report from an investigation company, a complete renovation has been proposed due to the general deterioration of the gray water pipes, and the construction cost will be high at 13 to 24 million yen, so the management association is still considering future measures.
table of contents
Repair of unit bath
Regarding the unit bath, we replaced the shower hook, shower hose, door stopper, and towel rack with new ones, and repaired the inspection door.
We also spent an entire day removing limescale stains from the FRP using cleaning tools and detergent (citric acid).
shower hook replacement
The material of the existing shower hooks is zinc die-casting, but due to aging, it was no surprise that they could be worn out over and over again. The old product has a 3-point fixation, but recently 2-point fixation has become mainstream, and no replacement product was found.
Therefore, I purchased the following SANEI shower hook ``Shower hanger'' and Kakudai's plate ``Shower hook stain hiding plate'' to hide the screw holes after removal from Monotaro (also sold on Amazon), and asked a professional to install them via Mitsumore. Since they are all made of metal, they look luxurious and have a long service life.
Shower hook parts list
Dirt hiding plate for shower hook
Manufacturer name/product number: Kakudai/358-112 or GAONA/GA-FW033
Sales price (tax included): ¥681
shower hanger
Manufacturer name/product number: SANEI (formerly Sanei Faucet Manufacturing)/PS30-25
Sales price (tax included): ¥1,868
shower hook specifications
Dirt hiding plate for shower hook
You can hide dirt on the wall or unused screw holes after removing the existing shower hook.
Luxurious stainless steel specifications.
<Specifications>
Material: Material stainless steel
shower hanger
<Specifications>
Screw fastening type (with screws)
Material: Zinc die-casting/Color: Plating/Installation method: Screw/Angle adjustment: ×
Installing the shower hook (before and after)
After waterproof caulking the hole where the old shower hook was removed, attach the hidden plate for the shower hook, and use a power drill to drill a hole in the top (reuse the existing bottom hole) to attach the shower hook.
The surface is made of FRP, but there are metal parts inside, so drilling holes requires careful consideration, so Mitsumoa decided to have a local professional do the work. The construction fee was 6,000 yen (+ 1,000 yen for parking).
door stopper replacement
The material of the old door stopper seems to be zinc die-casting, so it looked sturdy at first glance, but upon closer inspection, it was rusted and crumbling due to aging, so I decided to replace it with a new one.
This product was not available on Amazon, but fortunately, Monotaro had the exact same product on sale, ``RELIANCE Door Stopper Product Number R3019''.
door stopper parts
Manufacturer name/product number: RELIANCE/R3019
Sales price (tax included): ¥1,538
Door stopper specifications
The standard design is still used in hotels and residences nearly 40 years after its release.
A simple door stopper with surface mounting specifications.
<Specifications>
Color: Surface treatment chrome plating (main body)
Product dimensions: Length: 105 x Width: 40 (screw width 26) x Height: 25 mm (φ15)
Finish type: Zinc die-cast/Tip: Synthetic rubber (milky white)
Manufacturer name: RELIANCE
Product number: R3019
Installation type: Screw-in type (with mounting screws)
Installing the door stopper (before and after)
When removing the old door stopper, I managed to remove the top screw by injecting KURE 5-56, but the bottom screw does not turn at all and cannot be removed.
So, as a last resort, I tipped the door stopper bar downwards, but it broke easily and the main body came off, so I injected 5-56 again and turned the remaining parts with pliers, and succeeded in removing the screw!
Replacing the towel rack
The towel rack attached to the aluminum door was still in good condition, but the pipe was noticeably rusted, so I decided to replace it with a new one.
This product is "RELIANCE R722 Series Product Number R722-400" and was available from Amazon. Please note that Monotaro can only be purchased by businesses and is not sold to general consumers.
parts of towel rack
Manufacturer name/product number: RELIANCE/R722-400
Sales price (tax included): ¥2,442
Specifications of towel rack
Standard product used in hotels and residences.
This is a popular towel rack that can be used anywhere, even in the bathroom.
Bathroom availability: Yes
Material: Bracket/zinc die-cast, pipe/stainless steel
Finish/Color: Bracket/chrome plating, pipe/polishing
<Specifications>
Color: Chrome
Product dimensions: Length: 40 x Width: 47 (screw width 32) x Height: 58.5 mm (φ12.7)
Finish type: Chrome plated/polished
Manufacturer name: RELIANCE
Product number: R722-400
Installation type: Screw-in type (with mounting screws)
Installing the towel rack (before and after)
It was difficult to remove the old towel rack because the one screw on the bottom right couldn't turn, but after a lot of struggle, I was able to successfully remove it by injecting KURE 5-56.
Replacing the shower hose and installing the shower joint
As part of the small renovation of the shower room, we decided to replace the shower hose with a new one. I purchased "SANEI Shower Hose PS30-86TXA-W" from Amazon.
The faucet in the unit bath we are currently using is a KVK deck type 2-handle shower, but it can be attached to the mixer faucet using the included adapter.
In addition, since the shower head has an angle adjustment function, I did not think about the problem that the shower hook does not have an angle adjustment function, but after actually using it every day, I realized that it would be more convenient if the shower hook had an angle adjustment function.
As a solution to this problem, we installed a shower joint that allows you to freely change the angle of the shower head while hanging it on a hook.
The shower joint is installed between the shower head and shower hose. I also purchased "Kurika Shower Joint SJSW-1529" from Amazon.
shower hose parts
Manufacturer name/product number: SANEI/PS30-86TXA-W
Sales price (tax included): ¥1,727
Shower hose specifications
Made in Japan, this is a standard type shower hose with a length of 1.6m. The shower head mounting bracket is rotatable so the hose does not get twisted.
Comes with 5 types of adapters compatible with other manufacturers, so it can be installed with most manufacturers! *Please check the product image to see which manufacturers can be installed.
[Manufacturer that can be installed directly on the mixing faucet body]
SANEI, MYM, some LIXIL (INAX) products, Kakudai, TBC, YUKO, some MIZUTANI products, Noritz
[Manufacturers that can be installed with the included adapter]
TOTO (thick/thin hose), KVK, Gaster, LIXIL balance pot, Rinnai, some products of Osaka Gas
Warranty period: 1 year from purchase
⚠️ [When installing a shower head with a water stop function] If the water pressure is over 0.3 MPa, there is a risk of damage such as the hose fitting coming off due to sudden closure at the tip. We recommend using a pressure regulating valve (SANEI product number: PV710F).
<Specifications>
Material: Polyvinyl chloride (PVC)
Color: White
Product dimensions: 160 length x 2.6 width cm
Product weight: 0.4 kg
Maximum pressure: 108.77 lbs/in²
Outer diameter: 3 cm
Product length: 160 cm
Manufacturer: SANEI (former company name: Sanei Faucet Seisakusho)
shower joint parts
Manufacturer name/product number: Kurita/SJSW-1529
Sales price (tax included): ¥1,727
Shower joint specifications
A shower joint that allows you to change the direction and angle of the shower while hanging it on a hook.
Just attach it between the shower head and hose. Easy to install on your home shower head. You can use the shower at any angle without having to bend forward, so you can maintain a comfortable posture.
<Specifications>
Size: Approx. 4.1 x 4.1 x 6.1cm
Materials/Materials: [Main material] Polyacetal/Silicon
● Usable temperature: 1 to 60 degrees (please do not use at hot water temperatures over 60 degrees)
●The mounting screw size of this product is G1/2. Please check the screw size before purchasing as it may not be possible to install due to some special specifications or specification changes.
●This product is for bathroom shower use only. It cannot be installed on bathroom vanities or instant water heaters.
●It may not be possible to use extremely large or heavy items such as multi-functional shower heads.
●Installing this product may reduce the flow rate. Depending on the shower head, the flow rate may drop significantly.
Shower hose replacement (before and after)
(The built-in spring seems to be a part of the check valve.)
Installing the shower joint (before and after)
Repair of inspection port
Due to deterioration over time, cracks were already visible in some parts of the inspection port, so we waterproofed the front and back sides with caulking agent, pasted waterproof cushions, and reinstalled the inspection port. I also had a hard time getting the lower right screw for the inspection port to turn, but with the help of the 5-56 I managed to remove it.
Stubborn limescale had adhered to the inspection port and unit bath, so we used the following limescale removal tools and cleaning agent (citric acid) to remove the limescale that had adhered to the FRP. Furthermore, I caulked the top of the inspection port with bath caulk just to be sure.
By the way, since the "KYOWA" logo is engraved on the ventilation port of this unit bath, we believe that the manufacturer is Kyowa Seisakusho (KYOWA/NASTA), but this manufacturer has already stopped providing unit baths.
Therefore, there are currently no products on the market that are compatible with this inspection port, so as long as you continue to use this unit bath, you will have no choice but to continue using it carefully and repairing the inspection port along with the unit bath itself from time to time.
tool
Installation of inspection port (before and after)
2025.12.26 Added
DIY replacement of GOAL doorknob
As shown in the article below, I replaced the GOAL doorknob in the unit bath using DIY.
Replacing wardrobe hinges
Due to aging, the hinges of the old wardrobe broke. All three of the doors broke while I was opening and closing them, so I ordered angle hinges from Monotaro to replace them.
Production of this type of hinge has been discontinued in Japan, and we were unable to find parts of the exact same model, but we did find a compliant angle hinge in a different color, ``High Logic Angle Hinge 18×19 Part No. 17220''.
angle hinge parts
Manufacturer name/product number: High Logic/18×19 product number 17220
Sales price (tax included): ¥846
Angle hinge specifications
Material: Zinc die casting
Color: GB color
Nominal dimensions (mm): 18×19
AS ONE product number: 64-9700-93
Installation of angle hinge (before and after)
Reform history
For reference, the table below shows the history of renovation work carried out at my condominium over the past 24 years.
The total amount is 2,366,684 yen, which is 8,218 yen/month, so I think it's better than living in a rented house and paying high rent every month.
In addition, in the 2000s, work to replace water heaters and air conditioners (total cost of approximately 300,000 yen for 1 water heater and 3 air conditioners) occurred, but as the date of the work is unknown, it has been excluded from this list.
[Renovation construction implementation history…24 years]
| Year and month (Japanese calendar) | cost | Description |
|---|---|---|
| 850,500 yen | Renovation upon moving in: Replacement of wallpaper and flooring...Local construction company "Best Japan (Isehara)" | |
| July 2007 (2007) | 35,000 yen | Kitchen faucet replacement: TOTO kitchen single lever mixer faucet TKJ33U3R…Local plumber |
| March 2018 (2018) | 133,000 yen | Toilet/shower/toilet replacement…Local construction company “Asreform (Hiratsuka)” |
| October 2019 (The first year of Reiwa) | 80,000 yen | Water heater replacement…Kinriser |
| April 2020 (Reiwa 2nd year) | 110,000 yen | LED lighting in the living room: AIR PANEL (HH-CD0892A)/Japanese-style air conditioner replacement: Hitachi room air conditioner (RAS-KD22K)...K's Denki |
| June 2022 (Reiwa 4th year) | 19,000 yen | Applying UV film to the living room…Lifestyle Market “Glass Film Installation KTM” |
| November 2022 (Reiwa 4th year) | 402,700 yen | Renovation from a Japanese-style room to a Western-style room…Local construction company “Asreform (Hiratsuka)” |
| December 2024 (Reiwa 6th year) | 77,616 yen | Replaced window air conditioner with CORONA CWH-A1824R…Yahoo! Shopping |
| June 2025 (Reiwa 7th year) | 107,090 yen | Replacing the air conditioner in the Western room with DAIKIN S224ATCS...Kakaku.com (Mr. Air Conditioner) |
| August 2025 (Reiwa 7th year) | 93,580 yen | LED lighting in all rooms…Yamada Denki/Kakaku.com |
| September 2025 (Reiwa 7th year) | 70,161 yen | Replacement with door phone VL-SVD505S even outside...Kakaku.com (Construction Market) |
| November 2025 (Reiwa 7th year) | Replace the range hood, toilet bowl, and shower toilet with Noritz NFG6S25MSV & LIXIL Amage toilet bowl and New PASSO CW-EA22AQC...I can replace it. | |
| December 2025 (Reiwa 7th year) | 24,258 yen | Bathroom parts replacement (door stopper, shower hook, stain hiding plate for shower hook, towel rack, doorknob, etc.)...Monotaro & Amazon, installation by Mitsumore "Fujisawa Equipment" (7,000 yen) |
計 2,366,684円（8,218円）
