How Well Is Waterproofing Done in a Pre-Sale Home Bathroom, and How Should It Be Inspected Before Handover?

The warranty period is the clearest basis for home buyers. Under Point 17, Paragraph 1 of the Ministry of the Interior's “Required and Prohibited Items in Pre-Sale Home Sales Standard Contracts,” the seller guarantees structural parts (foundations, beams and columns, load-bearing walls, floor slabs, roofs, stairs, retaining walls, etc.) for 15 years, and fixed building materials and equipment (doors and windows, plastering, floor tiles, etc.) for 1 year. A Ministry of the Interior letter dated May 21, ROC Year 98 (2009) further explains that leaks in structural parts are warranted for 15 years, and leaks in fixed building materials and equipment are warranted for 1 year.

If the seller adds a “leak warranty” (titled “waterproofing warranty” in the letter) to the contract, the warranty period may not be shorter than the period required by the standard for the structural or fixed building materials and equipment. Whether a leak warranty is 15 years or 1 year depends on which category the leaking part belongs to, so buyers can ask the developer to state this clearly in the contract before signing.

For the handover inspection, the consumer protection officer at the Taichung City Government Legal Affairs Bureau recommends checking that building materials and equipment match the building material and equipment schedule in the contract. Plumbing and pipes must be tested, with water pressure in the bathroom and kitchen turned to maximum, and the toilet should be tested for proper flushing and any leaks. The 158 Spatial Information Network of the Taichung City Government Land Administration Bureau also offers downloads of the pre-sale home standard contracts that developers have filed for record, where buyers can check building materials and equipment, handover deadlines, and warranty terms.

As for water tests, the figures given by developers are not entirely consistent. 100 Interior Design says that after the waterproof layer is finished and before floor tiles are laid, the bathroom, balcony, and other areas should be flooded to a maximum depth of 2 to 3 centimeters, with the drains sealed, and tested for 24 to 48 hours. It adds that most professional standards recommend at least 24 hours, and 48 hours is safer. The TWProbe Real Estate Observation Station states that the area should be filled to a depth of 3 to 5 centimeters and left to stand for 48 hours, that the waterproof layer in the shower area should reach a height of at least 180 centimeters, and that the washbasin area should be at least 100 centimeters. The process used by absco involves adding about 3 to 5 centimeters of water, recording the initial water level and taking photos, checking every 12 hours, and confirming at the end that the water level has not dropped noticeably and that there are no signs of leaks in the unit below or in neighboring walls.

These water test practices are developers' own claims that address the construction stage before tiling. They are not official requirements. The TWProbe Real Estate Observation Station also notes that flexible cement waterproofing coating should be applied in 2 to 3 layers in a crisscross pattern, with a total thickness of 1.2mm to 1.5mm, and should not be applied thickly in a single coat.