Dryseal is a unique fully mechanically fixed single layer Glass Reinforced Polymer 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: Tested Under BS EN13501-5:2016 Dryseal will achieve a BROOF(t4) rating
Water absorption: < 3% (24hrs at 20ºC)
Water vapour resistance: 475MNs/g (75%RH, 25ºC)
Tensile strength: 112kN/M
Finish colour: Dryseal Dark 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.
Thickness: 1.3mm nominal
Length: 6.0m
Width: 1.25m
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.
Both Dryseal and other “single ply” materials can be supplied in appealing colours, with the standard product colours for each being light and dark (lead) grey. The supply of special colours for most single ply products requires a minimum production run of 2,000 m2 of membrane.
The advantage is held by Dryseal this instance as 25 kgs. is the minimum top coat special order, which equates to 50 m2 of completed roof.
The ability of Dryseal to be fitted with “rolls” to simulate the appearance of panelled lead gives it an advantage over single ply systems as the single ply rib is distinctly dissimilar to the appearance of a lead roll, being intended to replicate a folded sheet metal joint.
With the Dryseal system, both types of trim option are available.
Being a semi-rigid product, Dryseal can be fitted without bonding or further support to vertical or steep slopes using normal mechanical fixing methods. Other “single ply” products rely on adhesives to achieve this application, which may not be suitable on church roofs, due to most being close boarded timber. The possibility of membrane “sag” is not one that applies to Dryseal GRP sheet, especially in hot weather.
Dryseal is fitted as a completely mechanically fixed system, with the roof perimeter able to “breathe”. This enables a Dryseal covered roof to draw out any residual moisture left within a roof construction following re-roofing work and, unlike with other single membrane roof coverings, there is no reliance upon adhesives, sealants and termination bars to secure perimeter detailing, a process which effectively seals the roof edge.
Both types of product are light in weight, PVC type membrane generally being around 2 kgs. per m2 and Dryseal being 3 kgs. per m2. Compared with the weight of lead sheet of up to 36 kgs. per m2 (for Code 8 lead), the lighter weight of both single membrane products will not adversely affect the building structure and may prove to be an advantage, especially if insulation needs to be introduced to the roof build up during re-roofing.
PVC roofing membrane would typically provide 15% elongation to breaking point and more than 200 Newton tear resistance. Resistance to impact is generally 500mm with dropped object of 10mm diameter. Resistance to a static load is typically 20 kgs. per m2.
Dryseal GRP tensile elongation is 1.5%, inferior to PVC, but is perfectly sufficient to accommodate normal thermal expansion and contraction of the substrate. Expansion joints can be seamlessly incorporated into a Dryseal roof and fully laminated into the system.
Tested Under BS EN13501-5:2016 Dryseal will achieve a BROOF(t4) rating. Unlike thermoplastic materials that melt under the application of heat, Dryseal achieves the BROOF(t4) rating when laid directly onto combustible substrates such as timber, without the need to introduce fire retardant insulation. During the Dryseal installation process no naked flames or heat guns are used, considerably reducing the risk of fire. Dryseal has been tested and certified by Warrington Fire Laboratories.
Punctures, damage and failures at joints in thermoplastic membranes are often difficult to locate by inspection and may require the use of specialist leak detection equipment. PVC membranes can suffer from polymer migration during their life, especially in an acidic environment like a city location, posing problems with heat-welded repairs after some years. Similarly, once vulcanisation has taken place, FPO and TPO membranes can be difficult to clean and prepare for the purposes of repair.
Dryseal GRP can be simply abraded and repaired with resin lamination in the same manner throughout its whole life. No degradation or loss of constituent chemicals occurs with Dryseal GRP. On a timber roof Dryseal GRP is in excess of 20 times more puncture and load resistant than PVC membrane.
The harmful effects of PVC production are not widely known. PVC production employs carcinogens such as benzene and vinyl chloride. In addition, dioxins are one of the principal by-products of PVC manufacture. During the manufacture of Dryseal GRP, some styrene and other volatile organic compounds are released, however the industry standard of 4 kilogrammes per tonne of styrene used is huge by comparison to Hambleside Danelaw’s miniscule 15 grams per tonne.
Once installed on a roof, Dryseal GRP has no environmental effect on potable water, as there is no chemical “leeching” from it. Some single ply membranes can, in time, suffer from polymer migration, which is inevitably discharged into the environment.
Due to Hambleside Danelaw’s continued investment programme, a reduction in landfill waste of over 60% the last ten years plus a reduction of the company’s carbon footprint by 70% over the last five years have contributed to it being awarded BS EN ISO 14001 accreditation and Planet Positive certification. Dryseal is fully recyclable and the manufacturing plant in Daventry is amongst the most environmentally advanced in Europe.
In general, PVC, FPO and TPO/E membranes can be expected to last up to 30 years. Most carry a 20 year warranty on the product itself, with additional cost for an installation or insured warranty.
Dryseal carries a 20 year “leak free” guarantee which covers rectification of any defects, rather than supply of FOC goods. The installer separately guarantees his installation work for the first 5 years and the installation is covered by an insured warranty for the first 10 years, the cost of which is included in the product purchase price. Subject to normal maintenance and a re-application of top coat after 20 years, it is reasonable to expect the Dryseal GRP component based system to last for up to 30 years. It is not necessary to remove the Dryseal system to upgrade.
Overall, the facts stated above establish a strong argument for the use of Dryseal in preference to other “single ply” systems, on the grounds of cost, aesthetics, durability and environmental impact.
