A building expansion joint refers to a structural joint set along an appropriate location in the direction of the construction joint of a building or structure to prevent structural cracks or damage due to changes in climate and temperature (heat expansion, cold contraction).
Expansion joints divide the building components above the foundation, such as walls, floors, and roofs (except wooden roofs), into two independent parts, so that buildings or structures can be horizontally expanded and contracted along the long direction.
What if a water leakage problem in the expansion joint and analyse how to deal with the leakage of roof expansion joints?
1. Case of roofing expansion joint:
2. The location of the project is the expansion joint on the top floor of the shop. The structure is a reinforced concrete floor with a waterproof layer, an insulation layer and a protective layer. However, the maintenance of many expansion joints on the roof was not in place and leakage occurred.
3. Reverse beams were not installed on both sides of the expansion joints of the original pouring floor, and some parts were lower than the floor, and the drainage outlets were higher. In rainy seasons, drainage was not smooth, causing rainwater to pour into the expansion joints, and full water caused serious water leakage from the lower part.
4. The original waterproof layer was polypropylene fibre and have used ointment with SBS membrane for several repairs before, but water seeped again after the repair. After investigation, the main problem was that the waterproofing was not done on the structural layer (the waterproofing was done directly on the protective layer).), resulting in repeated leakage;
Analysis of leaking
Analysis: According to the analysis of the site situation, the water-stop on both sides of the expansion joint is too low, which is lower than the existing protective layer, which leads to leakage. The previous repair was simply waterproofing on the structural layer and could not achieve the waterstop effect.
Measures: Excavate to the structural layer, plant steel bars and re-cast the waterstop (after the surface is roughened, heighten the existing waterstop and pour fine stone concrete), and then use polyurethane to brush three oils and two cloths.
1. Base surface cleaning until the structural layer;
2. Slotting beside the previous waterstop;
3. Place the waterstop,
4. Use the formwork to re-cast the fine stone concrete waterstop, which is higher than the existing protective layer.
5. Brush with polyurethane
6. Pave waterproofing membrane;
7. Use polyurethane for edge banding details;
8. Leveling and reducing to make slopes;
9. Steel plate covering.
1. After the completion of the leakage repair project, it has withstood the rainy inspection, and there is no more leakage in the room.
1. For waterproofing, it is necessary to find out the cause of the leakage first, and the design plan should be combined with waterproofing and flexible.
2. Waterproof maintenance must first understand the structure of the project, start with the structure, and look for the cause.
3. The construction process must be meticulous and thoughtful, not afraid of trouble, especially some nodes, must be strengthened.