The waterproof renovation of the 7600㎡ factory building uses Haobang TPO self-adhesive waterproof membrane

Project Overview

Jiaolong Warehouse Roofing, located in Yancheng City, Jiangsu Province, is a wholly owned property of Jiangsu Jiaolong Industrial Investment Co., Ltd. The main structure of the factory building is an all-steel structure, with a roof constructed of 760-section corrugated steel sheeting. The building, covering 7,600 square meters, experienced leakage during its operation. Tianda Materials arrived on site in early April 2024 to begin construction.

1) Laying

Determine the placement of the first roll based on the profiled steel sheeting on-site. Since the width of the butyl self-adhesive TPO waterproofing roll is 2000mm, calculations indicate that after the first roll is laid along the first trough edge of the corrugated steel sheet, the long-side overlap of the second roll can remain within the trough plane of the second steel sheet. This method ensures that the long-side overlap of the rolls remains within the trough plane of the second steel sheet. This maximizes the utilization of the automatic hot air welder, reduces manual welding, and improves construction efficiency.

After determining the placement of the first roll, unroll it and lay it flat on the base surface to relieve stress generated during rewinding and minimize wrinkling caused by post-application shrinkage. Based on on-site construction conditions, the roll should be laid parallel to the long side of the corrugated steel sheeting, with the long-side overlap remaining within the trough plane as much as possible. Rewind the coil along its long edge, remove the release film on the back of one side, and apply the coil along the crests and troughs, ensuring it adheres fully to the corrugated steel sheet to avoid hollowing or loose adhesion. The overlapping short edges of two adjacent coils should be staggered by at least 300mm.

2) Compaction: Use a roller to compact the sheet material during application to ensure the butyl adhesive layer is fully adhered to the corrugated steel sheet. After the sheet material is compacted over the entire surface, use a dedicated tool to compact the inner corners on both sides of the trough to prevent hollowing.

3) Welding

All long-side overlaps of the butyl self-adhesive TPO membrane are welded using a hot-air welder, with the overlap width between the two membranes being 80mm. Before hot-air welding, a test weld is performed to adjust the welding temperature and speed. After the test weld, the membrane is cut into small pieces and peeled for testing. If cohesive failure between the membranes is observed, formal welding can begin. Before welding, the weld seam must be kept clean and free of contamination. If the weld has been exposed for an extended period, it should be cleaned with a clean cloth and a special cleaning solvent (xylene or vinyl acetate). Wait until the solvent has evaporated before hot-air welding.

4) Major Detail Joint Treatment

① Ridge Joint Treatment

First, apply self-adhesive TPO sheeting to the ridge. Then, weld a 200mm wide homogeneous TPO sheet to the self-adhesive TPO sheet at the ridge. Cut the wave crests, and finally repair and weld with homogeneous TPO sheeting.

② Skylight Joint Treatment

The entire skylight facade is wrapped with homogeneous TPO sheeting, secured at the top with a sealing strip, and sealed with silicone weatherproof sealant. The downward fold of the sheeting is welded to the main sheeting.

③ Gutter Joint Treatment

TPO sheeting is applied to the gutter bottom and facade. The facade sheeting is welded upward to the main surface. The wave crest cuts are repaired and welded with homogeneous TPO sheeting.

④ Downspout Node Treatment: Weld the homogeneous TPO membrane into a cylindrical shape and place it inside the downspout. Seal the bottom with silicone sealant and hot-air weld the upturned portion to the waterproof layer at the bottom of the gutter.

The success of every construction project is inseparable from the dedicated efforts of a strong team. Over the years, Haobang Waterproofing has helped numerous construction projects achieve honors through its commitment and dedication. In the future, Haobang Waterproofing will continue to work with clients to create more high-quality green buildings.