Roofing
Don & Low Nonwovens have over 10 years experience in the manufacture of roofing underlays for the European Construction Industry, selling under the Daltex® and private label branding.
Don & Low produce three principal classes of Daltex® Roofing underlays:
Very Low Resistance Vapour Permeable Underlays
Very low resistance underlays (VLR) have vapour resistance as low as 0.08 MNs/g (Sd =0.016m), and can be used in supported & unsupported roofing applications. Daltex® VLR underlays are also air permeable which can contribute substantially to reducing the risk of condensation in roofs. Where VLR underlays are specified it is not necessary to ventilate the roof, providing the fabric is installed in accordance with the relevant Agrément Certificate. These VLR underlays can also be used in conventional ventilated roof constructions.
Don & Low produce the following VLR underlays:
- Daltex® RoofTX® Pro
Low Resistance Vapour Permeable Underlays
Low Resistance (LR) underlays have a vapour resistance less than 0.25 MNs/g (Sd <0.05m), and can be used in supported & unsupported roofing applications. Where LR underlays are specified: it is not necessary to ventilate the roof, providing the fabric is installed in accordance with the relevant Agrément Certificate. LR membranes can also be used in conventional ventilated roof constructions.
Don & Low produce the following LR underlays:
- Daltex® RoofTX® Ultra
- Daltex® RoofTX®
High Resistance Barrier Underlay
High Resistance (HR) underlays resist the diffusion of water vapour, with a vapour resistance greater than 0.25 MNs/g (Sd >0.05m). HR underlays are a durable alternative to traditional bituminous based felts (BS 747, 1F), and where these underlays are specified it will be necessary to provide ventilation to enclosed roof voids and cavities.
Don & Low produce the following HR barrier underlay:
- Daltex® MultiTX® Plus
Vapour Control Layers
A high resistance (vapour impermeable) membrane, having a vapour resistance at least 10MNs/g (Sd > 2) which is placed on the warm side of the construction, i.e. inside the thermal insulation in cold climates. A VCL should extend over the whole area of the element into which it is incorporated and must be integrated with and sealed to adjoining elements, including adjoining VCL’s, up-stands, abutments and glazing systems.
Don & Low produce the following VCL:
- Daltex® MultiTX® Control
