There are approximately 5.88 million houses in Taiwan that are over 30 years old, accounting for more than half of the total housing stock. As the government promotes the "Old Houses Life Extension Functional Renovation Project", the need for repairs of old houses has gradually attracted attention. However, in addition to improving the appearance and interior decoration, renovation of old houses also poses water leakage problems. The problem is a project that homeowners cannot ignore, from cracks in the exterior walls, aging of the roof waterproofing layer, to leaking bathroom pipes. If the source of the leakage is not found before construction, even if it is re-decorated, you may still face wall cancer, peeling paint, or even repeated dismantling and repairs after moving in.
The government has promoted a three-year life extension policy for old houses and compiled a special budget of 5 billion yuan to provide indoor and outdoor repair subsidies for apartments with 4 to 6 floors over 30 years old (inclusive) and residential buildings with roofs below 6 floors. The projects include building facade repairs, roof waterproofing and insulation, and public pipeline updates, etc., making waterproofing and repair projects for old houses an important project to improve the living environment.
Chen Hongming, founder and architect of LiLeju, said that the common locations of leaks in old houses are mainly the exterior walls, roofs and bathrooms. Exterior walls are affected by the sun, rain and temperature changes for a long time, and are prone to problems such as coating aging, damage to tile gaps, and failure of window frame caulking. When rainwater penetrates along cracks or joints, it may cause indoor wall moisture, wall cancer and peeling paint. If concrete peeling or exposed steel bars have occurred, the damage to the building should be further inspected.
Common problems on roofs and terraces include aging of the waterproof layer, blockage of the water head, and poor edge closing at the junction of the parapet. Even if the waterproof layer is not obviously damaged, if the drainage slope is insufficient and water accumulates for a long time, the risk of leakage may increase. Before construction, the original waterproof layer, drainage holes, and wall junctions should be inspected. If necessary, the failed waterproof layer should be removed and reinstalled.
As for bathroom leakage, in addition to damage to the waterproof layer of the floor, it may also come from the junction of the wall and the floor, poor sealing around the drainage pipe, or damage to the water supply and drainage pipeline. If you only re-fill the gaps in the tiles or apply silicone without finding the actual location of the leak, the problem often cannot be solved. Therefore, the waterproofing construction and water test inspection should be completed before the bathroom is renovated.
There are also different considerations in selecting waterproof materials. Common waterproof materials can be divided into water-based and oil-based. Water-based includes acrylic waterproof paint, EVA resin and elastic cement, while oil-based includes systems such as polyurethane waterproof coating (PU) and polyurea. Various materials vary in elongation, tensile strength, weather resistance and applicable base surface. The selection should be based on the construction location and environmental conditions, and cannot be judged purely by price or coating thickness.
Take the bathroom and toilet project as an example. Before construction, the base surface should be treated and the drainage slope should be confirmed to avoid water accumulation on the floor. Then waterproof materials should be applied in layers according to product specifications. Wall-floor junctions, pipeline penetrations, water heads and thresholds must also be strengthened. After the waterproof layer is completed, it must be fully maintained according to material requirements, and then a water test should be conducted to confirm that there is no leakage before proceeding to subsequent processes such as tiling.
Chen Hongming reminded that the renovation of old houses should not just deal with the visible walls and decorations. The waterproofing project should be confirmed one by one from the cause of leakage, base surface treatment, material selection to construction inspection. In particular, the reasons for water seepage in the roof, exterior walls and bathrooms are different, and corresponding construction methods should be adopted. Before entrusting the construction, the owner should also confirm the project project, acceptance method and warranty conditions to avoid discovering that the leakage problem has not been solved after the surface renovation is completed.
