Home > Companies > Hambleside Danelaw Ltd > Dryseal Semi-rigid Cold Roof System

A roof covering system comprising GRP (Glass Reinforced Polyester) thermoset materials, laid as a single layer over the whole roof surface, including upstands and flashings. The single applied layer is covered by Dryseal Top Coat, a high-performance, liquid applied, protective coating.

Dryseal is designed for flat and low pitched roofs. The roofing system is suited to both new and refurbishment projects, from small domestic to large commercial and industrial applications. It can be used to upgrade or refurbish existing roofs, incorporating additional insulation.

Dryseal can be used for cold, warm and inverted roofs and can incorporate non-slip walkways within the system.

Dryseal involves a special production process which applies a high adhesive surface to the components, creating an excellent surface for secondary bonding processes such as detail working, jointing and top coat application.

The Dryseal Top Coat is applied to the GRP membrane and roofing details as a further protection against UV light degradation and is available in light or dark grey as standard, or in a selection of other colours to order. When used for walkways, the top coat can be made slip resistant.

Performance:

Dryseal GRP roofing system with polyester top coat has been tested to the conditions laid down in BS 476-3: 1975 extended fire exposure roof test and has been designated FAC.

Durability:

Dryseal roofing products have a life expectancy in excess of 30 years. Environmental and specification factors can affect the life expectancy and regular care and maintenance can assist to considerably lengthen the life span.

Guarantee:

Dryseal offers a leak-free insurance backed guarantee of 20 years , provided the system has been installed in accordance with the manufacturer’s instructions contained in the Technical Manual. Contact Hambleside Danelaw for further information.

Design considerations:

The Dryseal system is suitable for the covering of most types of roof decking, with the exception of strawboard, which should be stripped out and replaced with a suitable alternative material.

Dryseal is compatible with any roofing insulation board which will withstand normal foot traffic when fixed, in whatever thickness is required to achieve the specified U-value. A designated walkway must be installed if the roof is to be subjected to regular traffic for maintenance or plant room access, either by forming from heavy duty sheet, identified by using a different coloured top coat, or by using approved walkway tiles, or walkway matting.

Insulation in warm roof applications is generally loose laid with staggered joints, the stiffness of membrane and the regularity of seam fixing being sufficient restraint. Hard objects immediately below the membrane, such as fasteners and pressure plates, are acceptable but not preferred.

Dryseal can be used in "cut-to-falls" insulation schemes, subject to the approval of detail by Hambleside Danelaw’s technical service department. Dryseal roofs should not be subject to any point loading without adequate protection, i.e. timber support under ladders.

Preparation:

  • For new construction: The roof decking is to be of sound construction. Surface to be dry, free from debris, oil, grease and chemical contaminants.
  • For refurbishment: Clear roof of any debris. Cut and reseal any blisters and reinforce weak areas in an approved manner to form an adequate vapour control layer.
  • For refurbishment (with chippings): Remove existing chippings where possible, to a sound surface. Cut and reseal any blisters and reinforce weak areas to form an adequate vapour control layer.
  • For refurbishment (asphalt): Clear roof of any debris. Any blisters to be reheated and made level. Reinforce weak areas.
  • For refurbishment (Paropa roof): Mark out roof for provision of vents at the rate of one vent per 40 m². Cut hole through Paropa slab, existing roof membrane to substrate. Clear roof of all debris.

On refurbishment projects, a separation layer should be used below the membrane when the existing roof covering is not being removed.

A protection layer may be installed above or below membrane (e.g. plywood below to protect from damage from above).

Attachment:

  • Mechanically attached with adhesive bonding to roof perimeter trims.
  • The membrane is never fully or partially bonded except at roof perimeter trims to prevent chattering.

Substrate movement/ expansion joints:

The membrane, being mechanically fixed, can accommodate some movement in the substrate and in the membrane itself. Specific movement joints in the structure can be accommodated by using specific trims or combinations of trims from within the wide range of Dryseal preformed components.

Surface protection:

Walkway tiles / matting / slabs / timber decking.

Health and safety:

Dryseal Polyester Resin, Top Coat and cleaning solution products are particularly hazardous and must be used strictly in accordance with manufacturer’s recommendations. The vapour given off is heavier than air and may spread along floors. Vapour may form explosive mixtures with air. Sources of ignition should be removed, including naked lights. Electrical equipment should be protected to the appropriate standard. Smoking, eating and drinking should be prohibited in application areas. The products also require the use of personal protection, including antistatic clothing, respiratory protection, safety eyewear and hand protection.

The use of these products must be included in the Health and Safety Plan.

Related literature

The following content references this product:

Standard product features

Waterproof membrane:

- H1250F Dryseal Flat Sheet:

  • Manufactured in widths up to 1250 mm.
  • Nominal thickness: 1.3 mm.
  • Roll length 6 metres, longer lengths available on order.
  • Colour: Top coat available in dark grey or light grey. Other colours available to order.

- H1250R Dryseal RibTec Sheet:

  • Manufactured in widths up to 1250 mm.
  • Nominal thickness: 1.3 mm.
  • Roll length 6 metres, longer lengths available on order.
  • Colour: Top coat available in dark grey or light grey. Other colours available to order.

Options

Trims, flashings, cappings for coping tops and cover flashings, manufactured from GRP:

  • H0200A and H0250A: Flat edge/ drip trims — a range of pre-formed GRP roof edge details for use where drainage is required. Available in a range of fascia depths.
  • H0240B and H0260B: Raised edge/ check kerb — a range of pre-formed GRP roof edge details for use where prevention of water run-off is required. Available in a range of fascia depths.
  • UACF: Simulated lead wall cover flashing trim — for use to replace traditional lead flashings.
  • H0260D: Wall fillets — for use against abutments, providing for expansion and cross-roof ventilation.
  • H0300F: Continuous flashing — a 300 mm wide flashing for use where a continuous narrow strip of membrane is required. Available in 30 m rolls, longer lengths are available on order.
  • H0150G, H0275G, H0150H and H0275H: Internal and external angles — for use when 90° angle details are required.
  • H0280J and H0380J: Internal flexible angle — for use when a 30° to 50° angle is required, e.g. at deck to lay board detail.
  • H0065K and H0130K: Coping trims — to cover existing coping on parapets, etc.

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
20-50-30/160 Single layer cold roof covering system

NBS Specification

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This product is associated with the following NBS clauses:

Product specification

An important note about specifying

Manufacturer

Name:

Hambleside Danelaw Ltd

Tel:

+44 (0)1327 701900

Product reference

Dryseal Semi-rigid Roofing System

Separating layer

[ ______ ]

Waterproof membrane

[H 1250 F Flat Sheet Membrane]
[H 1250 R RibTec Membrane]

Colour

[Dark grey]
-
Standard colour.
[Light grey]
-
Standard colour.
[Colour]
-
any RAL or BS number colour match, depending upon quantity.

Attachment

Mechanical, with adhesive bonding to roof perimeter trims

Perimeter trims

[H0200A – flat edge/ drip 90 mm x 90 mm]
[H0250A – flat edge/ drip 90 mm x 140 mm]
[H0240B - raised edge kerb 105 mm x 120 mm]
[H0260B – raised edge/ kerb – 125 mm x 120 mm]
[UACF – wall/ cover flashing – 100 mm x 35 mm]
[H0260D – wall fillet – 120 mm x 60 mm x 80 mm]
[H0280E – pre-formed expansion joint – 70 mm x 200 mm]
[H0150SR - 114mm x 30mm high decorative rib trim to simulate zinc or aluminium]
[H04030R - 80mm x 30mm decorative Easirib roll to simulate lead]
[H0300F – continuous flat flashing – 300 mm wide]
[H0275G 90° – external angle – 75 mm x 200 mm]
[H0150G 90° – external angle – 75 mm x 75 mm]
[H0150H 90° – internal angle – 75 mm x 75 mm]
[H0275H 90° – internal angle – 75 mm x 200 mm]
[H0170 35/ 50° – flexible internal angle – 90 mm x 80 mm]
[H0170A 35/ 50° – flexible external angle – 90 x 80 mm]
[H0280J 60/ 70° – flexible internal angle – 200 mm x 80 mm]
[H0380JA 35/ 50° – flexible internal angle – 300 mm x 80 mm]
[H0065K – coping/ capping trim – 65 mm x 230 mm]
[H0130K – coping/ capping trim – 130 mm x 160 mm]
[TRB200 – galvanized trim retaining brackets]
[TRB250 – galvanized trim retaining brackets]

Upper protection layer

[ ______ ]

Membrane Walkway

[ ______ ]

Accessories

[Perimeter trims]
[Galvanized steel trim support brackets]

Manufacturer details

Hambleside Danelaw Ltd,
Long March,
Daventry,
Northamptonshire, NN11 4NR
Tel +44 (0)1327 701900
Fax +44 (0)1327 701909
NBS Plus
RIBA CPD