How to Waterproof Mobile Prefab Toilets

Waterproofing mobile prefab toilets requires a comprehensive approach covering materials, construction, structure, joint treatment, and acceptance inspection. Specific measures are as follows:

I. Material Selection

Waterproof materials must possess weather resistance, flexibility, and anti-aging properties.

• Waterproof Coatings: Preferably use polyurethane, epoxy, or acrylate-based coatings that can form a continuous elastic membrane layer, adapting to slight deformations of the prefab structure.
• Waterproof Blankets/Membranes: Polymer, SBS, or APP waterproof blankets are suitable for base layer coverage; PVC, butyl rubber, or EPDM membranes offer strong corrosion resistance and are ideal for joint sealing.
• Waterproof Adhesives: Epoxy or polyurethane adhesives are used for crack repair, requiring high bonding strength and water pressure resistance.
• Auxiliary Materials: Sealing strips, weather-resistant adhesives, and water stops are used for joint sealing and must be compatible with the main materials.

II. Construction Key Points

1. Surface Layer Treatment

• Thoroughly clean the base layer, removing oil stains and dust, and level it with cement mortar, ensuring a slope of ≥2% for drainage.
• When covering with waterproof materials, the ground should extend 30-50cm up the wall to form a 'basin-style' waterproof layer.

2. Sealing Treatment

• For wall-floor junctions and pipe roots, adopt the 'one fabric, three coats' process: first apply waterproof coating, then reinforce with non-woven fabric, and apply two more coats of coating.
• Wrap drainage pipe connections with flexible waterproof cement, then with waterproof tape, and provide inspection ports for easy maintenance.

3. Leakage and Crack Treatment

• Micro-cracks should be filled with waterproof adhesive and then covered with a waterproof blanket; wide cracks require a V-shaped groove to be cut, filled with waterproof adhesive, or the damaged panel replaced.
• Regularly inspect the roof and walls for leakage points, using high-pressure grouting or local repairs as needed.

III. Structural Design

• Box Material: Choose high-strength galvanized steel or stainless steel, coated with anti-corrosion paint on the surface, and grind and paint welding joints smoothly.
• Waterproof Coating: Spray polyurea or silane impregnation coating on the outer layer of the box to form a dense waterproof layer.
• Anti-Backflow Design: Install a 10-15cm high waterproof threshold at the door frame and use inward-opening doors and windows to prevent rainwater intrusion.

IV. Key Joint Waterproofing Details

• Pipe Penetrations: Install stainless steel water stops, then fill gaps with flexible waterproof cement, wrap with PVC waterproof sleeves, and seal.
• Door and Window Frame Perimeters: Pre-embed waterproof gaskets, fill gaps with polyurethane foam adhesive, and seal the outer edges with silicone weather-resistant adhesive.
• Panel Joints: First fill with elastic sealant, then apply butyl rubber waterproof tape, and finally brush with polyurethane waterproof coating.

V. Quality Acceptance Standards

• Closed Water Test: Maintain a water depth of ≥20mm for 24 hours without leakage.
• Water Spray Test: Spray nodes with 0.3MPa pressure water for 30 minutes, checking for no wet traces on walls, floors, or joints.
• Document Verification: During acceptance, provide material certificates, construction records, and closed water/water spray test reports.

By implementing systematic waterproofing measures, the durability of mobile prefab toilets can be significantly enhanced, reducing long-term maintenance costs.