Technical Guidance

Dryseal System Data


Dryseal is a unique fully mechanically fixed single layer Glass Reinforced Polyester thermosetting membrane and trim component based roof waterproofing system.  The area to be waterproofed is fully encapsulated by factory manufactured components that are fixed through underlying layers of insulation or over an existing roof covering to the substrate using purpose designed fixing plates and a range of approved fixing types depending upon the substrate type.

All joints and details are waterproofed by the application of site applied GRP laminate prior to the application of a UV protective finishing top coat and weathering surface.


Dryseal System (Installed)Weight: <3kg/m² (subject to fixing type and numbers used)
Thermal conductivity (k-value): 0.2W/mK
Thermal transmittance (U-value): 5.7W/m²K
Co-efficient of expansion: 22 x 10-6m/m per °C
Fire classification: F.AC to BS 476-3 (laid directly over combustible timber substrate)
Water absorption: < 3% (24hrs at 20ºC)
Water vapour resistance: 475MNs/g (75%RH, 25ºC)
Tensile strength: 112kN/M
Finish colour: Dryseal Dark Grey or Dryseal Light Grey (other colours are available to special order)
Min./Max. gradient: No restriction
Roof access: Restricted access only unless surface protection provided.


Sunlight: UV stabilised resin used in flat sheet, trims and jointing resins. UV resistant top coat.
Chemicals: Compatible with all established construction materials. Resistant to most airborne pollutants, however certain acids, alkalis and solutions of water soluble gases may attack the GRP and fixings.
Biological: Resistant to root penetration and attack by micro-organisms, fungi, larvae, insects and mildew.

Dryseal Membrane Dimensions

Thickness: 1.3mm nominal
Length: 6.0m
Width: 1.25m

Dryseal Trims

Thickness: 1.3mm nominal
Length: 3.0m

Fixing plates (DP40): 40mm diameter glass filled polyamide
Jointing resin: Special purpose pre-accelerated orthophthalic polyester resin
Joint reinforcement: 450g/m² chopped strand glass mat with 30g/m² glass surface tissue
Top coat: Special purpose pre-accelerated isophthalic polyester resin

Handling and Storage

All components of the system should be handled with due care and stored in a dry ventilated area in the original packaging and protected against frost, weathering, UV exposure, pollution, contamination and mechanical damage. Storage temperatures should not fall below 5°C for use or exceed 25°C. All liquids should be stored in accordance with the Highly Flammable Liquids Regulations 1972. Material Safety Data Sheets available separately.

Guarantee and Warranty

The system has an expected service life in excess of 30 years and carries a 20 year “leak free” manufacturer’s guarantee with a 10 year installer’s  guarantee and an insurance-backed warranty.  Documentation available separately.

This Guarantee shall only apply to product installed by approved installation contractors and exposed to normal weather conditions within northern European Union countries. It is subject to the system and its components being stored in accordance with the above recommendations and fitted in accordance with the recommendations and details contained within the Dryseal Technical Manual.

The Guarantee does not extend to cover damage caused by abnormal movement or use of the roof, accidental or malicious damage or deterioration of the product colour because of natural weathering conditions.

  • All the information contained within this data sheet is provided in good faith and without guarantee or warranty.
  • Hambleside Danelaw reserves the right to change the specification of its products at any time.
  • No liability can be accepted for any losses, claims or demands that may arise as a result of the information provided in this data sheet.
  • This statement does not affect statutory rights.