Parabit Duo Hot Applied Roofing Systems

Approved for use on

Flat Roofs Green Roofs Inverted Roofs Podium Decks Protected Roofs Roof Gardens Zero Falls Buried Roofs 

For use as a waterproofing layer during installation on flat roofs, including zero fall, with limited access in:

• inverted roof specifications
• protected roof specifications (including podium deck roofs), eg covered by pavers or other suitable protection
• roof gardens or green roof systems.

Substrate

Concrete Timber 

Concrete substrates to which the systems are to be applied must comply with the relevant requirements of BS 6229 : 2003 and, where appropriate, NHBC Standards 2018, Chapter 7.1. The following substrates are suitable for use with the systems:

• in-situ structural concrete
• precast concrete
• concrete block in vertical applications
• lightweight structural concrete (subject to the manufacturer’s recommendations)
• new exterior grade plywood (to BS EN 636 : 2003, Clause 8), fixed in accordance with the relevant requirements of BS 6229 : 2003 and BS 8217 : 2005.

Durability

Design Life of the Roof 

When fully protected and subject to normal service conditions, the systems can provide an effective barrier to the transmission of liquid water and water vapour for the design life of the roof in which they are incorporated.

Installation Requirements

The systems should only be installed by trained contractors using specialist equipment.

Fire Safety

The systems, when protected by an inorganic covering (eg gravel or paving slabs) listed in the Annex of Commission Decision 2000/553/EC, can be considered to be unrestricted under the national Building Regulations.

A roof garden covered with a drainage layer of gravel 100 mm thick and a soil layer of 300 mm thick will also be unrestricted.

In the opinion of the BBA, when used in irrigated roof gardens or green roofs the membranes will also be unrestricted.

Exposed areas of the capsheets, when used with one of the surface finishes detailed in Approved Document B, Appendix A, Table A5, part iii (England and Wales) and Technical Booklet E, Table 4.6, part iv (Northern Ireland) (listed below), would be deemed to be unrestricted:

• bitumen-bedded stone chippings covering the whole surface to a depth of not less than 12.5 mm
• bitumen-bedded tiles of non-combustible materials
• sand and cement screed
• macadam.

The designation of exposed areas of the capsheets installed to other specifications should be confirmed by: England and Wales — test or assessment in accordance with Approved Document B, Appendix A, Clause 1. Scotland — test to conform to Mandatory Standard 2.8, clause 2.8.1, Northern Ireland — test or assessment by a UKAS-accredited laboratory, or an independent consultant with appropriate experience.

If allowed to dry, plants used in a roof garden may allow flame spread across the roof. This should be taken into consideration when selecting the plants. Appropriate planting irrigation and/or protection must be applied to ensure that the overall fire-rating of the roof is not compromised.