Revised code of practice for slating & tiling
On 31 August 2014, the British Standard for tiling and roofing (BS 5534) was updated. The new standard became mandatory at the end of February 2015.
THE CHANGES TO THE BRITISH STANDARD RELATE TO:
- Application of a non-supported roofs.
- Scottish sarking / timber plank type roofs are also subject to the new standard as square edged butt-jointed planks are not considered to be airtight and are therefore to be treated as unsupported.
- Both cold and warm roofs.
- Securing the membrane to prevent ‘ballooning’ as this would put pressure on the tiles or slates and can cause dislodgement.
- New minimum performance requirements for wind uplift resistance of breather membranes.
- New test method for calculating the wind pressure and wind uplift of unsupported underlays (i.e. draped over the rafters – most common method of cold roof construction in England).
- Geographical wind zone map with areas 1 to 5.
- Different widths of batten gauges (i.e. centre to centre) up to 345 mm.
- Fully supported roofs (on e.g. plywood, OSB board and insulation) are excluded from the amendments of
BS 5534:2014 + A1:2015.
Powerlon UltraPerm breather membranes have undergone further testing from the BBA/BRE and the results have shown that all 4 grades of the range cover Zones 1-5. (See colour coding system).
Powerlon UltraPerm is a range of high performance breathable underlays for all pitched roof designs and wall applications (timber frame). It is tough, durable and tear resistant with exceptional water vapour permeability and hydrophobic (water repellent) characteristics.
The BBA certified Powerlon UltraPerm range is fully tested to the latest BS 5534:2014 + A1:2015 zones 1-5.
UltraPerm is a non-woven composite membrane and is available with and without integrated self-adhesive strips. Pre-printed marking lines for both roof pitch and overlaps for supported and unsupported roofs make installation quicker and easier. Complementing the membranes is the Powerbond range of accessories which includes penetration and jointing tapes.
Each roll is supplied with detailed installation instructions and a colour-coded geographical suitability guide per wind zone and membrane grade.