Universal breathable roofing underlay for all pitched roof designs and wall applications. Fully compliant to BS 5534:2014 + A1:2015

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 roofing underlay roll is supplied with detailed installation instructions and a colour-coded geographical suitability guide per wind zone and membrane grade.

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.

Revised code of practice for slating & tiling

The new BS 5534: 2014 + A1: 2015 is based on the conditions below, which must be applied to the building and site concerned.

• • • Ridge height not greater than 15m
    • Roof pitch between 12.5 and 75 degrees
    • Site altitude not greater than 100m
    • No significant site topography
    • Maximum uplift deflection of the underlay no greater than 35mm
    • Underlays can be used in applications conforming to the above building and site conditions in all wind zones provided that their wind uplift resistance at a batten gauge of 345mm is not less than;
    • 1600N/m2 when a well-sealed ceiling is present
    • 1900N/m2 when no ceiling or no well-sealed ceiling is present
    • 2350N/m2 when no ceiling or no well-sealed ceiling is present and permanent dominant opening is present on an external face of the building.

Underlays used in applications conforming to the building and site conditions given above, including a well-sealed ceiling (see BS 9250), should be classified in accordance with their geographic location and

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.

wind zone, see table figure below. Underlays should be used only
in those wind zones for which the design wind pressure is not greater than the declared wind uplift resistance for the underlay, at the batten gauge tested.

The need to ventilate, or otherwise, roofs with insulation installed above, between or below the rafters differs from roofs with insulation installed above a horizontal ceiling. A well-sealed ceiling and an AVCL should always be provided. See the Powerlon AVCL range for more information. Table below taken from BS 5534: 2014 + A1: 2015.

The breather membrane minimum result depends on the building, the site distance to sea, the building height and type of terrain (country or town).

* Maximum wind design pressure of the underlay is 70% of the maximum wind velocity, e.g. 1166 x 70% = 816 N/m2. Min pressure/Wind Zone 1 = 820 Pa, see Fig.1

• Universal breather for roofs and walls
• British Board of Agrément (BBA) certified (Certificate No. 13/5037)
• CE Approved
• BS 5534: 2014 + A1: 2015 compliance
• 5 grades with and without integrated tapes
• High water vapour permeability
• Pre-printed marking lines
• Fully illustrated installation instructions
• Customised printing available

POWERLON ROOFING UNDERLAY: OUTSTANDING TECHNICAL PERFORMANCE

CUSTOMISED PRINTING

Powerlon UltraPerm can be customised and printed for corporate branding, product identification and advertising. Powerlon SP100 (house-wrap) is also custom printable.