TPO waterproofing membrane is a sheet waterproofing material made of TPO elastomer as the base material, flame retardant filler, weather-resistant pigment, antioxidant and light stabilizer, etc., through high-speed stirring, melt extrusion and calendering. In the early 1990s, it was used in roof waterproofing projects by mechanical fixing and paving. Because it has both the weather resistance of EPDM rubber and the weldability of plastic waterproofing membrane, the waterproof effect is reliable, so it has developed rapidly.

Mechanical fixing structure

Schematic diagram of mechanical fixing system

Construction process

TPO waterproofing membrane mechanical fixing system construction process: preliminary preparation → base treatment → laying vapor barrier layer → mechanical fixing insulation layer → mechanical fixing membrane → welding membrane → detail node processing.

Mechanical fixing system construction flow chart

1. Preliminary preparation

Before construction, the membrane and system supporting materials should be prepared in full according to the required varieties and specifications; and the quality should be inspected to meet the relevant standards. Do not destroy the original packaging of TPO membrane, and store it in a cool place and cover it with canvas.

2. Base treatment

The base must be flat, dry, clean, without hollows, sand, cracks, etc. Water, ice or snow must be removed to prevent moisture absorption in the new roof part and layer system. Before laying the roll material, remove debris and foreign matter on the base.

3. Laying the vapor barrier

The vapor barrier should be laid perpendicular to the corrugation direction of the corrugated steel plate. It should be flat, continuous and undamaged. The overlap width is 100mm and special tape is used for bonding.

4. Mechanically fix the insulation layer

The insulation layer should be laid continuously and tightly. There should be no gaps between adjacent insulation boards. When using double-layer insulation materials, they must be laid staggered and fixed with mechanical fasteners.

5. Mechanically fix the roll material

First, lay out the line. The laying direction of the roll material should be perpendicular to the corrugation direction of the corrugated steel plate. During construction, pre-laying should be carried out first. The naturally loose roll material should be arranged on the base according to the contour. It should be flat and straight without distortion. The overlap width is 120mm. Use fixings to fix the rolls, and install the fixings according to the designed fixing positions. The edge of the fixings should be 15~20mm away from the edge of the roll. The center spacing of the fixings is determined by the local wind speed, the type of structural base, the height of the building and the width of the roll. Under normal circumstances, the center spacing of the fixings is 150-450mm.

6. Welding rolls

Use an automatic hot air welding machine or a handheld hot air welding machine to weld TPO rolls with hot air. When the roof slope exceeds 1/13, it is inconvenient to use an automatic hot air welding machine. It is recommended to use a handheld hot air welding machine. Place adjacent rolls to form a 120mm overlap where the fixings are placed (along the length of the roll), and the hot air welding width is at least 40mm.

7. Detailed node processing

Roll closing: The TPO waterproof roll should be fixed with professional closing strips and closing screws at the closing, and sealed with sealing paste. Yin and Yang corner processing: Additional rolls are added by welding at the Yin and Yang corners. The additional rolls are folded and cut according to the shapes of each place and then welded. Prefabricated corner parts are preferred.