화장실방수공사 typically costs between 1,200,000 won and 2,500,000 won depending on the bathroom size and the extent of demolition required. This post outlines the pricing factors, preparation steps, material choices, and common failure points you need to evaluate before hiring a contractor. Understanding these technical variables prevents unexpected expenses and structural damage later.
How tile demolition and base preparation drive the pricing
The primary cost driver in any bathroom waterproofing project is the labor required to strip the old surface down to the structural concrete slab. If a contractor applies new layers over existing tiles without proper removal, the bonding fails within two to three years. The crew must remove all floor tiles, wall tiles up to a height of 30 centimeters, and the underlying mortar bed. Debris disposal fees usually add an extra 150,000 won to 300,000 won depending on building elevator access and local waste regulations.
After clearing the debris, workers inspect the bare concrete for hidden cracks around the floor drain and pipe penetrations. Any hollow spots or honeycombing in the concrete must be chipped out and patched with high-strength non-shrink grout. Skipping this preparation stage accounts for over 70 percent of recurrent leaks in multi-family residential buildings. The concrete surface must dry completely before any liquid membrane goes down.
Choosing between liquid mortar layers and modern membrane systems
Contractors generally offer two main application methods that differ in curing time, thickness, and elasticity. Traditional cementitious methods use a dense cement slurry that bonds rigidly with the concrete substrate. In contrast, applying a liquid elastomeric coating provides a seamless rubberized barrier that can bridge minor hairline cracks caused by structural settling. Homeowners often weigh these options based on budget constraints and the expected lifespan of the building.
| Item | Cementitious Method | Elastomeric Coating |
|---|---|---|
| Material Cost | Low | Moderate |
| Curing Time | 48 hours | 24 hours |
| Crack Bridging | Poor | Excellent |
| Expected Lifespan | 5 years | 10 years |
Step by step sequence of a standard wet room restoration
A proper installation follows a strict sequence that cannot be rushed without risking moisture penetration. Each layer requires specific drying intervals to achieve its maximum tensile strength.
- Strip existing tiles, fixtures, and deteriorated mortar down to the structural concrete slab.
- Apply a penetrating primer to seal concrete pores and improve adhesion for subsequent layers.
- Brush liquid waterproofing agent around pipe penetrations, wall corners, and floor drains as a primary reinforcement.
- Apply two full coats of elastomeric membrane across the entire floor and lower wall surfaces, allowing 12 hours of drying time between coats.
- Conduct a 48-hour water holding test by plugging the drain and filling the floor area to verify zero leakage before laying new tiles.
Common mistakes that cause premature membrane failure
Many failures occur because installers neglect the critical junction where the floor meets the wall. Water travels easily along these 90-degree corners if fabric reinforcement strips are omitted during the coating application. Another frequent error is tiling over a damp concrete bed, which traps moisture inside and causes the tile adhesive to lose bond strength. Finally, rushing the water holding test before the chemical curing process finishes can permanently weaken the waterproofing membrane.
Frequently asked questions about 화장실방수공사
How long does a standard bathroom waterproofing project take?
Most residential projects take between four to six days from initial demolition to final fixture reinstallation. This timeline includes demolition, concrete curing, membrane application, the 48-hour water test, and tile setting.
Can I waterproof over my old bathroom tiles to save money?
Applying new sealants directly over existing tiles is not recommended because it raises the floor height and fails to address degraded sub-floor mortar. True remediation requires full demolition to expose and repair the structural concrete.
Who is legally responsible for leak repairs in shared buildings?
Responsibility depends on whether the leak originates from private internal pipes or faulty shared drainage stacks. If the failure stems from a private bathroom waterproofing defect, the owner of that specific unit bears the repair costs.
Proper planning and strict adherence to curing times ensure that 화장실방수공사 remains durable for over a decade without structural leaks.