The bathroom is one of the areas in a rental property that deteriorates most easily. In particular, leaving caulking (sealing) deterioration unaddressed can lead to water leaks and structural corrosion, causing repair costs to rise substantially. This article explains how to protect asset value through regular maintenance.
Why is bathroom caulking repair important?
Caulking refers to the sealing material applied to joints between different building materials, such as between the bathtub and wall, between the wall and floor, and in tile joints. It plays an important role in ensuring waterproofing.
Caulking typically lasts 5 to 10 years, and when it deteriorates, the following problems can occur.
- Water leaks: Water enters through gaps and can cause leakage damage to the floor below
- Mold growth: Mold can spread in deteriorated gaps and become a cause of health issues
- Structural corrosion: Prolonged leakage can rot wood and make large-scale repairs necessary
How can you identify caulking deterioration?
If you see the following symptoms, the caulking needs to be replaced.
- Cracks: Fine cracks appear on the surface of the caulking
- Separation: The caulking is peeling away from the wall or bathtub
- Discoloration and black mold: Mold has penetrated into the caulking itself
- Hardening: It has lost elasticity and feels hard even when pressed with a finger
- Shrinkage: The caulking has contracted and gaps have formed
What are the cost and process for caulking replacement work?
| Work Item | Estimated Cost | Time Required |
|---|---|---|
| Bathroom caulking replacement (full set) | JPY 20,000 to 50,000 | 2 to 3 hours |
| Around the kitchen sink | JPY 10,000 to 30,000 | 1 to 2 hours |
| Around the washbasin | JPY 10,000 to 20,000 | 1 hour |
| Around the toilet | JPY 8,000 to 15,000 | 30 minutes to 1 hour |
What is the maintenance checklist for the entire bathroom?
- Check the condition of the caulking (once a year)
- Clean the drain and test drainage (at move-out and before move-in)
- Clean the ventilation fan filter and check operation (once every six months)
- Remove water scale from the mirror and fixtures and check operation
- Check the bathtub for cracks and discoloration
- Check tile joints for cracks and lifting
Bathroom maintenance FAQ
Q1. Who pays for caulking replacement?
Age-related caulking deterioration is the owner's responsibility. However, if repairs are required because of improper use by a tenant, for example if mold was left untreated and the damage worsened, the cost may be charged to the tenant.
Q2. When is it generally time to replace a unit bath?
A unit bath typically has a service life of 15 to 20 years. If deterioration reaches a level that cannot be addressed by caulking replacement alone, such as cracks in the tub or bulging walls, it is time to consider replacing the entire unit bath.
Q3. How much does bathroom cleaning cost at move-out?
House cleaning for a bathroom typically costs JPY 15,000 to 30,000 per unit. Additional charges apply if mold removal or limescale polishing is required. Regular maintenance can help keep cleaning costs under control.
