Newton Hydrobond 402 Waterproofing Membrane – Pre-Applied Type A System
 
Newton Hydrobond 402 is a high-performance pre-applied waterproofing membrane designed for the external waterproofing of below-ground structures such as basements, foundations, water holding tanks, culverts and tunnels.
 
This sheet membrane is engineered to form a full mechanical bond with newly poured concrete and is compatible with a range of below-ground waterproofing systems to create a continuous Type A (barrier) waterproof envelope around your project.
 
Hydrobond 402’s composite structure — combining a durable LDPE layer with a non-woven geotextile fleece — provides exceptional crack-bridging performance and resistance to movement, ensuring robust long-term protection against water ingress.
 
Key Benefits
 
Pre-applied external waterproofing membrane for below-ground structures
Full mechanical bond to concrete prevents lateral water migration
Excellent flexibility & crack-bridging performance
High strength peel adhesion once concrete cures into the membrane
Integrates with other Hydrobond products for complete waterproofing systems
Suitable for domestic basements to large civil engineering applications
 
Typical Applications
 
External waterproofing for basements and earth-retained structures
Waterproof envelope below concrete raft/slab and wall building lines
Water holding tanks, culverts and tunnel base waterproofing
Combined with other Hydrobond pre- and post-applied membranes as a full system
 
Performance & Compatibility
 
HydroBond 402 sits within the Newton HydroBond System of Type A barrier solutions and can be tied into other membranes (such as HydroBond 403 & HydroBond 401 SA) for complete site waterproofing and, if required, radon/ground gas protection (please contact us if you need these specialist membranes)
 
Technical Data
 
Property
Value
Product Type
Pre-applied external waterproofing membrane
Waterproofing Classification
Type A (Barrier Protection)
Membrane Construction
LDPE sheet with non-woven geotextile fleece
Bonding Method
Full mechanical bond to freshly poured concrete
Thickness
Approx. 1.2 mm
Roll Size
1.0 m × 20 m (20 m² per roll)
Weight
Approx. 1.6 kg/m²
Tensile Strength
High tensile and tear resistance
Crack-Bridging
Excellent flexibility and crack-bridging performance
Water Permeability
Completely impermeable to liquid water
Vapour Permeability
Vapour resistant
Chemical Resistance
Resistant to groundwater salts and contaminants
Installation Temperature
Suitable for typical UK construction conditions
Application
Pre-applied to formwork or substrate before concrete pour
Use Location
External, below-ground structures
Compatible Standards
Designed to comply with BS 8102:2022
System Compatibility
Integrates with Newton HydroBond system components
 
Installation Overview (Also See Full Installation Guide)
 
Installed before concrete placement
Laid with fleece side facing concrete pour
Overlaps sealed using compatible HydroBond tapes and accessories
Concrete cures into fleece layer to create permanent bond
Prevents lateral water migration between membrane and structure
 
FAQs
 
What is HydroBond 402 membrane used for?

HydroBond 402 is a pre-applied waterproofing membrane used externally on below-ground structures to create a Type A waterproof barrier.
 
How does HydroBond 402 bond to concrete?

The membrane’s geotextile fleece is encapsulated by wet concrete, forming a mechanical bond that prevents water migration between the membrane and structure.
 
Can this membrane be part of a full waterproofing system?

Yes. It integrates with other HydroBond products (pre- and post-applied) to form a continuous barrier around the structure.
 
Is HydroBond 402 flexible?

Yes — the composite sheet membrane offers flexibility and excellent crack-bridging to accommodate substrate movement.
 
What structures is it suitable for?

HydroBond 402 is suitable for domestic basements, foundation walls, retaining structures, water tanks and larger civil engineering below-ground applications.