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Integrated Roof Insulation and Waterproofing Solution

◣ Physical Properties of Spray-Applied Rigid Polyurethane Foam for Roofing

Project	Performance Requirements			Experimental method
Project	Type I	Type II	Type III	Experimental method
Apparent density (kg/m³)	≥35	≥45	≥55	GB/T 6343
Thermal conductivity (at an average temperature of 25°C) [W/(m·K)]	≤0.024	≤0.024	≤0.024	GB/T 10294 GB/T 10295
Compression Performance (10% Strain) (kPa)	≥150	≥200	≥300	GB/T 8813
Water impermeability (no skin formation, 0.2 MPa, 30 min)	—	Impervious	Impervious	—
Dimensional Stability (70°C, 48 h) (%)	≤1.5	≤1.5	≤1.0	GB/T 8811
Closed-cell rate (%)	≥90	≥92	≥95	GB/T 10799
Water Absorption (V/V) (%)	≤3	≤2	≤1	GB/T 8810

◣ Process Overview

Sprayed rigid polyurethane foam is classified into three types based on its material properties and can be used for roofs and walls, respectively.

Type I: This material exhibits excellent thermal insulation performance and can be used as an insulating layer for roofs and exterior walls.

Type II: In addition to its excellent thermal insulation performance, this material also offers a certain degree of waterproofing. When the Type II spray‑applied rigid polyurethane foam is combined with crack‑resistant polymer‑modified cement mortar, the resulting insulation–waterproofing layer can serve as an independent waterproof barrier. A roof composite insulation–waterproofing system composed of Type II rigid polyurethane foam and crack‑resistant polymer‑modified cement mortar can simultaneously function as both a waterproofing layer and a protective layer. Thanks to their strong adhesion, along with the surface’s water resistance, crack resistance, durability against puncture and aging, and the elimination of the need for expansion joints, there is no requirement to apply an additional protective layer over the composite insulation–waterproofing system.

Type III: In addition to its excellent thermal insulation performance, this material also exhibits superior waterproofing properties, making it an integrated thermal‑insulation and waterproofing product. It can be used as a single waterproofing layer and is primarily applied to roofs, serving both as an insulation layer and a waterproofing layer. The rigid polyurethane foam roof insulation and waterproofing system formed by Type III spray‑applied rigid polyurethane foam must not be exposed directly. Since rigid polyurethane foam is susceptible to direct ultraviolet radiation, prolonged sun exposure can lead to aging and chalking, thereby reducing its service life; therefore, a protective coating must be applied to the surface.

If the roof is a green roof, a rigid protective layer shall be provided. For rigid polyurethane foam protective layers, a 40-mm-thick fine aggregate concrete screed is typically used.

Polyurea Waterproofing Solutions

None!