Complete Bituminous Membrane Waterproofing Guide

2. Bituminous Membrane Types

   1.  Atactic Polypropylene (APP) Membrane

• Bitumen mixed with plastic.
• Strong resistance to heat and UV rays
• Ideal for roofs that are exposed
• Utilising the torch-on technique
  
  

2.  Styrene-Butadiene-Styrene, or SBS Membrane

• Bitumen that has been changed with rubber
• Excellent flexibility and resilience to cracking
• Suitable for regions that are prone to movement and colder climates
• Cold-applied or torch-on
  
  

3. Bituminous Membrane with Self-Adhesion

• Peel-and-stick style
• No need for a flame
• Safer in small areas

3. Application Areas

• Flat roofs, terraces
• podiums
• exterior basements
• retaining walls
• restrooms and wet areas
• foundations
• parking decks

4. Method of Stage-by-Stage Application

1. Preparing the Surface

• Dust, laitance, and loose particles must be removed.
• concrete surface must be dry and smooth.
• Fix uneven sections, honeycombs, and fissures.
  
  

2. Initial Application

• Use bituminous priming to increase adhesion.
• Let it cure for four to six hours.
  
  

3. Laying Membranes

• Properly position and roll out the membrane.
• Use a gas torch to warm the underside.
• To adhere to the surface, firmly press.
• Keep the end overlap at 100 mm and the side overlap at 75 mm.
  
  

4. Sealing joints

• Carefully heat and seal overlaps
• no air pockets or gaps permitted
  
  

5. Layer of Protection

• Use tile or paver blocks or protective screed (40–50 mm).
• If the membrane is exposed use a UV protection coat.

5. Advantages

• High tensile strength
• outstanding water resistance
• uniform thickness that is ready-made
• good crack-bridging ability
• suitability for high water pressure locations
• Durable (8–15 years)

6.  Drawbacks

• Needs professional personnel
• The torch-on approach poses a fire danger.
• It is not breathable
• Joints need to be precisely sealed.
• Once covered, repair work becomes challenging.

7.  Ideal For:

• Concrete roofs that are flat
• Basements that are externally waterproofed
• Regularly exposed areas to water
• Large, level surfaces