Waterproofing of Mobile Prefab Toilets

The waterproofing design of mobile prefab toilets achieves efficient waterproofing through material selection, structural optimization, and waterproofing grade classification, as reflected in the following aspects:

1. Material Waterproofing Characteristics

The exterior wall materials of mobile prefab toilets are primarily metal panels (such as color-coated steel sheets) or plastic panels (such as PVC sheets). These materials inherently possess waterproof and corrosion-resistant properties. Metal panels are treated with galvanization or coatings on their surfaces to effectively resist rainwater erosion; plastic panels achieve airtightness through their polymer structure, preventing moisture penetration. Roofing materials typically include waterproof membranes or metal tiles, combined with sealing strips, to ensure no leakage risks at joints.

2. Structural Drainage Design

Adopting a sloped roof structure is a key waterproofing measure. The sloped design accelerates rainwater runoff, reduces the likelihood of water accumulation, and prevents long-term soaking that could lead to material aging or leakage. Some designs also incorporate gutters at the roof edges to channel rainwater into the ground drainage system, further minimizing leakage risks. Additionally, the junctions between the floor and walls are rounded to prevent water from backing up into the wall interiors.

3. Waterproofing Grade Classification and Construction Requirements

Mobile toilets are classified into four waterproofing grades, each corresponding to different usage scenarios and construction standards:

• Grade 1 (Splash-proof): Suitable for high-demand locations (such as airport and station restrooms). High-durability materials (such as SBS modified bitumen waterproof membranes) are required. During construction, the substrate must be flat, and joint sealing must be strict to ensure complete waterproofing.
• Grade 2 (Spray-proof): Used in ordinary public restrooms. The waterproof layer has a moderate thickness, with a focus on treating details such as pipe penetrations and junctions between floors and walls. A small amount of dampness is allowed, but no leakage.
• Grade 3 (Storm-proof): Intended for general temporary facilities. Waterstops or waterproof coatings are required to enhance anti-permeability. A small number of leakage points are allowed, but no continuous water flow or sand leakage.
• Grade 4 (Prolonged Storm-proof): Suitable for low-frequency usage scenarios such as construction sites. The waterproof layer has the thinnest thickness, with an emphasis on basic treatment (such as concrete leveling). A small amount of leakage is allowed, but the leakage rate must not exceed 2L/m²/d.

4. Construction and Maintenance Points

During the construction phase, strict control over material quality is essential to ensure that the thickness and overlap length of the waterproof layer meet standards. During use, regular inspections should be conducted to check for blockages in the sloped roof, aging of sealing strips, and timely cleaning of drainage pipes to extend the waterproofing lifespan. In high-humidity environments, ventilation equipment can be added to reduce condensation water erosion on the structure.