My house is located on the top floor. Every time it rains, the ceiling in one of the rooms starts to leak. In severe cases, even water drips down. I searched online for several waterproofing contractors to have them inspect the roof. Some said the roof’s waterproofing was defective and needed to be completely renovated; others said it was a condensation phenomenon caused by moisture in the air, unrelated to waterproofing. Who is telling the truth? Is there a more scientifically sound method of determining this?
A: Our company has been engaged in waterproofing for 40 years, and we encounter at least one or two similar disputes every year. Sometimes it’s a public official (helping people assess the damage), sometimes it’s the customer (we handle the waterproofing of the roof), and clients often argue with us face-to-face. In any case, it’s very difficult to convince them. In fact, based on years of experience, whether the leak is caused by water or condensation can be easily determined just by looking at the appearance of the “water droplets.”
- If it is caused by water impermeability, the water droplets usually have a whitish tinge because they pass through the steel reinforcement and concrete from the roof.(Contains a small amount of carbonate)Or reddish in color(Add some iron oxide)While the water droplets are usually clear and transparent and spread out in a regular pattern.
- If it is caused by water impermeability, the water droplets usually pass through the steel reinforcement and concrete from the roof.PHThe value is alkaline, while the water in the condensation is acidic.PHThe value is usually neutral—this can be checked using a litmus test.
- If it is caused by water seepage, the ceiling paint will become more and more wet with each scrape; conversely, the more the water seeps in, the drier it becomes.
- When there is condensation water on the ceiling, temporarily block the roof drainage holes and collect the water. Test the water for several hours; then observe the ceiling from inside and make a judgment. At this time, if you use a fan to blow on the area where the ceiling beads are located,1 In an hour, if there is condensation, the more you blow, the drier it will get; conversely, if there is a leak, it is impossible.
- In the previous test, the fastest method is to dry the roof after it gets waterlogged by using a gas-powered fan to blow air from the ceiling inside the house. If there is condensation, it will dry immediately; otherwise, if there is a leak, it will not be possible to dry it.
- The main reasons for the formation of condensation water are excessive indoor humidity, poor ventilation, or temperature differences between indoors and outdoors.(Just like taking a soda bottle out of the refrigerator, after a few minutes the water bubbles will appear on the outside of the bottle as well.)The resulting situation is that the houses built on slopes often have no ventilation in the rooms or windows, rarely being inhabited, or the doors and windows are rarely opened or closed, and the relative humidity in the climate is relatively high.(Especially the southwest wind.)It is easy to see condensation water when it is raining.
- Is there any waterproof material that can improve the above phenomenon? The answer is no; this kind of physical phenomenon in this climate can only be solved through physical means.(Things like installing a dehumidifier, opening the windows to allow air circulation…)Improvement is impossible for any chemical material; usually, the more water that condenses, the more it adheres to the material with low pore surface area, and the smoother the surface is, the easier it is to cause condensation.
- Since the quality of waterproof manufacturers in the market is uneven, if disputes regarding water leakage or condensation cannot be resolved through mutual persuasion, it is best to entrust the task to a professional waterproofing organization.(Such as the Taiwan Construction Waterproof Technology Association(AbbreviationWTA)To verify the information, please do not blindly believe erroneous messages and add to your own troubles.