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SikaShield® VB P42 S 3 mm

SikaShield® VB P42 S 3 mm

118 mil bituminous vapor barrier, torch-applied

SikaShield® VB P42 S 3 mm is a 118 mil thick APP modified bituminous roofing vapor control layer. It is reinforced with glass fiber to provide a barrier to the passage of vapor. The top surface is coated with a smooth surface, which ensures the bond of the overlying layer. The underside of the product has a burn-off film for easy torch application or a non-woven polypropylene fabric for cold or hot application.

  • It can be left exposed for up to 12 months
  • Vapor diffuser and waterproofing incorporated in the same membrane
  • High resistance to water vapor movement
  • Easy to install
  • Fully bonded
  • Good durability
 
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Usage

The Product is used as a vapor barrier for:
  • Flat and sloped roofs
  • High humidity roof spaces (+20 °C / 68 °F ≤ 80 % RH)
 

Advantages

  • It can be left exposed for up to 12 months
  • Vapor diffuser and waterproofing incorporated in the same membrane
  • High resistance to water vapor movement
  • Easy to install
  • Fully bonded
  • Good durability
 

Packaging

Roll width

39.4" (1.0 m)

Roll length

32.8 ft (10.0 m)

Product Details

Product Information

Chemical Base

APP-modified bitumen

Reinforcing Material

Glass Fiber

Shelf Life

36 months from date of production

Storage Conditions

The Product must be stored in original unopened and undamaged packaging in dry conditions and temperatures between 41°F (5°C) and 95°F (35°C). Store in a vertical position. Do not stack pallets of the rolls on top of each other, or under pallets of any other materials during transport or storage. Always refer to packaging.

Top surface

Sand

Bottom Surface

Polyethylene (PE) burn-off foil. The "SF" version features a non-won polypropylene fabric for cold/mop application

Thickness

118 mil (3 mm)

(ASTM D5147)
Technical Information

Tensile Strength

Longitudinal (MD)

52.8 lbf/in

Transversal (CMD)

23.3 lbf/in

Elongation

Longitudinal (MD)

3.3 %

Transversal (CMD)

3.2 %

Permeability to Water Vapor

0.377 ng/(Pa·s·m²)

0.007 Perms

(ASTM E96)

Low Temperature Bend

≤ 14°F (-10°C)

(ASTM D5147)

Application

Application Information

Ambient Air Temperature

Maximum

41°F (5°C)

Minimum

104°F (40°C)

Relative Air Humidity

Maximum

80 %

Substrate Temperature

Maximum

41°F (5°C)

Minimum

104°F (40°C)
Application steps

SUBSTRATE QUALITY

SYSTEM DESIGN

Consider the following when designing the system:

  • The supporting structure must be of sufficient structural strength to support all new and existing layers of the system build-up.

  • If used as a roof system, the complete system must be designed to withstand and be secured against wind uplift loadings.

       

SUBSTRATE CONDITION

The substrate surface must be uniform, firm, smooth and free of any sharp protrusion or burrs, clean, dry, free of grease, laitance, oil, dust and loosely adhering particles.

APPLICATION

ALIGNMENT

To avoid coinciding joints, lay the membranes parallel to one another. When applying on another bituminous membrane, make sure to straddle the overlaps of the previous layer.

  1. Unroll the membrane.
  2. Align the membrane.
  3. Re-roll the membrane before application.

            

MEMBRANE OVERLAPS

  1. Overlap the membranes by a minimum of 4" (100 mm) on the sides and 6" (150 mm) on each end or as specified by the supplier.
  2. At the end overlap, cut off a corner measuring 4" (100 mm) per side at an angle of 45°.

               

TORCHING

  1. Heat the substrate and the backing film on the underside of the membrane with a gas burner.
  2. When the backing film starts to melt, the membrane is ready to stick.
  3. Roll the heated membrane forward and press it firmly against the substrate to bond it.
  4. Make sure a bead of melted bitumen is visible along the full length of the overlap sides and ends when laying.

                

Suitable substrates for torching

  • Concrete
  • Perlite screed
  • Bituminous membranes with a smooth surface
  • Coatings (check the compatibility)
  • Brick masonry
  • Cementitious screeds

             

DETAILING

Use a sharp knife to cut in all details such as internal and external corners, upstands, vent pipes, drains, support metalwork etc.

  

Refer to the relevant method statement for further information on detailing.

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