If waterproofing is not done properly, all renovations will be reimbursed! The Ultimate Guide to Whole-House Waterproofing: From Balcony to Bathroom to Exterior Walls

Waterproofing is the most worth investing in invisible armor in decoration

In humid and rainy Taipei, if the waterproofing project is done well, it will be sunny every day after moving in; if it is done sloppily, no matter how beautiful the decoration is, it may be destroyed by wall cancer and water damage. Many people think that waterproofing is just a matter of scrubbing the bathroom floor. In fact, true waterproofing is a "systematic project" that requires customized protection for different areas and materials in the home.

This budget buys peace of mind for the next ten or even decades. It is definitely one of the most non-negotiable items in decoration.

Different spaces require different waterproofing strategies

1. Bathroom waterproofing: the top priority
The bathroom is a "negative water pressure zone", and accumulated water will work its way into the gaps. The standard construction procedure should be:
(1) Dismantle to the structure, clean the base, and repair holes and cracks.
(2) Construct a "water-stop pier": Use non-shrinkage cement to make a small low wall at the edge of the threshold and shower area to prevent water from seeping from the ground floor.
(3) Strengthen pipe edges and yin and yang corners: Around all drainage pipes and at the corners of walls and floors, first use waterproofing materials or resin mortar to make arc corners and cover them with anti-cracking mesh. This is the weak point most prone to cracking and leakage.
(4) Fully coated with waterproof material: the wall should be at least 180 cm high in the shower area and 30 cm high in other areas. The ground needs to be completely covered. Apply at least two coats, cross-coating to ensure uniform thickness.
(5) Closed water test (stagnant water test): This is the ironclad rule for acceptance! Block all drainage holes on the ground, drain water to a depth of at least 3-5 cm, let it sit for 24-48 hours, and check for leaks on the ceilings of the residents downstairs. If the test is not passed, subsequent tiling must not be carried out.

2. Waterproofing of kitchens and working balconies
Although there is no water accumulation in the bathroom as often as in the bathroom, the risk of water splashing and pipeline leakage is high. The floor should be waterproofed throughout the room, and the walls should be 30-50 centimeters high behind the dishwasher, washing machine and around the sink. Don’t forget that the waterproofing layer must extend a little to the outside of the sill to form a complete wrap.

3. Waterproofing of exterior walls and window frames
Common water leakage in old houses in Taipei mostly comes from cracks in the exterior walls or aging window caulking. The radical cure needs to start outdoors: remove the old loose caulking and inject special low-modulus silicone (good elasticity, resistant to sunlight and rain). If the exterior wall tiles are peeling off or have large cracks, a professional leak detection team will need to perform high-pressure injection of foaming resin or apply a waterproof layer to the exterior wall. Waterproofing indoor walls can only treat the symptoms, and water vapor will still accumulate in the structure.

4. The roof and terrace are waterproof
The area is large and can directly withstand the test of sun, rain and temperature difference. In addition to coating waterproof materials, a layer of "waterproof blanket" or "insulation bricks" is often laid as a protective layer to prevent the waterproof layer from embrittlement due to ultraviolet rays. Whether the design of the drainage slope is smooth is the key.

Comparison of common waterproofing materials on the market

• Elastic cement (acrylic resin system): The most common household waterproofing material. The advantages are convenient construction, moderate price and certain flexibility. Suitable for bathrooms and balconies. When selecting, pay attention to values ​​such as "elasticity modulus" and "adhesion strength".
• PU waterproof material (polyurethane): It has excellent elasticity and can withstand slight thermal expansion and contraction of the structure. However, it is afraid of ultraviolet rays. When applied to roofs or terraces, a protective layer must be made on the surface. During construction, the requirements for environmental humidity and substrate dryness are relatively high.
• Penetrating crystalline waterproofing material: Special chemical formula can penetrate into the pores of concrete to produce crystals and block waterways. Suitable for negative water pressure moisture proofing on the inside of structures (such as basement walls), or as reinforcement for concrete structures.
• Waterproof blanket (asphalt series or polymer series): A rolling material like a blanket, laid on it. The waterproofing effect is reliable, but the joints need to be baked or glued, which requires high construction technology. It is mostly used on roofs or large projects.

What should you pay attention to during the acceptance of waterproofing projects?

1. Is the substrate flat, solid, and clean? Dust, oil, and loose cement will affect the adhesion.
2. Is the waterproof layer "continuous" and "complete"? Check whether the coating is in place on the corners, pipe edges, thresholds and other details. There should be no omissions or too thin coating.
3. The closed water test must be done! This is the only scientific method that can prove that waterproofing is effective. Either personally or by entrusting a designer to go to the residents’ homes downstairs to confirm.
4. Be careful when constructing the protective layer: When the tiling masters enter the site later, remind them to be careful when constructing on the waterproof layer to avoid shovels, ladders and other tools from puncturing the waterproof layer. Once damaged, it must be repaired immediately.

Remember one core concept: Waterproofing is a "system", not a "coating". From base treatment, detail enhancement, material selection to complete coverage, no care is taken in every aspect. Investing in a solid waterproofing project is buying the longest-lasting property insurance for your home.