Product Details
PERMAVENT ECO
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PRODUCT DESCRIPTION PERMAVENT-ECO is a three layered multi-use polypropylene membrane combining high permeability and excellent watertightness. Breather membranes cater for the “health” of your house. Don’t cut corners by using old 1F type felt or low performing first generation permeable underlays. PERMAVENT-ECO can be used on cold vented, non vented, warm deck and hybrid roofs (habitable roof space). We have the solution designed for you. Use Permavent-Eco at affordable price and meet all the NEW building regulations at the same time! |
PERMAVENT will provide a dry healthy enviroment in your home
PERMAVENT has been designed through intensive testing to meet the requirement in your home
PERMAVENT has been manufactured with the latest technology in accordance with E.U. standards
PERMAVENT can be used as part of an energy efficient roof system
PERMAVENT proven track record throughout Europe is fast approaching the number one choice in both specification and supplier
PHYSICAL PROPERTIES
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Surface mass density |
90 g/m2 |
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Vapour permeability |
1960 g/m2/24hr |
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Vapour resistance |
0.11 MNSgm-1 |
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Thickness |
0.6 mm |
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Resistance to UV |
3 months |
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Resistance to tear |
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— longitudinal: |
>189 N/5 cm |
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— transversal: |
>134 N/5 cm |
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Temperature range |
-40 °C +95 °C |
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Resistance at nailing point |
>188 N |
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Watertightness |
>5270 mm H2O !!! |
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Roll size: 1,5 & 1 m x 50 m |
50m2 & 75 m2 |
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Number of rolls per pallet |
30 |
* Other roll sizes are available upon request
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High Vapour Permeability PERMAVENT'S high tech design will protect your home from damaging effects of condensation |
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Absolute watertightness PERMAVENT SYSTEM ensures a dry home during prolonged construction or roof damage |
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UV Protected PERMAVENT shows no degradation under sunlight for 3 month operation efficiently between 95 °C max<45 °C min |
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Light weight PERMAVENT is easy to use, handle and store. Available in rolls of 1m x 50m (5.8 kg) and 1.5m x 50m (8.6 kg) |
WHY USE BREATHER
Part 'E' of the approved documents (conservation of fuel and power) is fast becoming the governments political tool and pressure to save energy is becoming a main issue in modern building design.
The latest additions to the building regulations has seen the introduction of air testing modern buildings alongside building design changes such as requirements to cover the thermal bridge and avoid non-ventilated voids.
The use of Permavent breather membranes is now an important tool in modern construction
The energy efficient cold non vented roof style can only be undertaken using breather membrane technology. By eliminating the drafts that are part of a traditional roof space the heat loss of the home can be reduced by up to 25%.
Almost all of the problems with new homes concern condensation and have come about through bad practise. It is critical that breather membranes are used correctly.
The correct use of Permavent breather membranes will drastically improve the impact of condensation in the new home.
INSTALLATION GUIDE
In all cases we recommend that;
Before installing the breather membrane and on the roof you should ensure that
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The ventilation requirements have been met.
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The top of the brickwork cavities are closed.
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The Insulation must be correctly installed at the wall plate in order to avoid a thermal bridge.
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The eaves guard is correctly installed
During the installation you should ensure that;
When walking on the roof always step on the battens at the point where it is nailed to the rafter. As with all membranes avoid undue pressure on the laid breather felt. Moving the felt under the battens can stretch a hole in the felt around the nail. Although this does not affect the purpose or performance of the membrane this can cause a leak around the nails if it rains heavily before the roof is fully covered in. If it is critical to avoid this rare occurrence we recommend that 'Tactape' is first applied to the underside of a counter batten that is then nailed and adhered up each rafter.
Each roll has detailed fitting instructions included. The breather membrane must be installed with the writing on the outside of the building. When laid directly over the rafters Permavent should not be pulled taught but allowed to naturally sag a little (2-5mm) in order to allow moisture to run under the battens.
Care should always be taken when working at height. The safety of all working in construction is critical, above and below.
Overlaps and joins
Permavent has standard hatching that indicates a 100mm overlap. Overlaps should be increased on lower pitches up to as much as 200mm on shallow pitches below 20 degrees. Valleys and hips should be overlapped by at least 300mm.
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Taping the overlaps and joins using Tactape on the breather felt will virtually eliminate the problems caused by wind uplift. It will also eliminate the rare occasions when Wind driven rain can be forced under the overlaps if the roof is not yet covered in during a storm. Large volumes of rain will course down the membrane in sheets and capillary action can draw the rain between the un-taped overlaps. |
These laps can then blow open and the rain can enter the roof space.
Fixing
Permavent can be nailed or stapled above the overlap marking line at the top of the membrane. This will then be covered by the overlap of the next run of membrane that is joined and held in place using Tactape. Roofing battens will hold the membrane in place and allow the installer to work up the roof.
Exposure
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Permavent is a high performance and technically advanced membrane that has been designed to combat condensation. The slate or tile covering is the protection against weather and Permavent should not be used a final roof covering. Although Permavent has special additives in order to protect it against the harmful effects of the sun, you should keep exposure to the sunlight to a minimum and limit exposure to not more than 3 months. |
Permavent should not be allowed to drape into the gutter but should be started just behind the fascia line.
Counter battens
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should be used for two reasons. Firstly; if the roof is fully boarded using sarking or insulation boards in conjunction with traditional horizontal battens then a counter batten of minimum 10mm should be first laid vertically. This would allow any moisture (that would get trapped) to run under these battens and out into the gutter. |
Secondly; if the space between the membrane and the roof covering requires ventilation then a counter batten of minimum 25mm when combined with a traditional 25mm batten will allow 50mm of free air space.
Insulation between the rafters
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If do not want to use counter battens when designing a warm room that has insulation between the rafters you should ensure that a 10mm gap is left at the top of the insulation. This will allow the membrane to sag between the rafters (i.e max 90mm insulation fitted between 100mm rafters) and the insulation requirements can be fully met by completely insulating across the underside of the rafters. |
Scottish Practice. This membrane is suitable for the Scottish practice of applying the slates directly onto the membrane that is laid without battens over a fully sarked (or boarded) roof. Sarking boards should incorporate a 2mm gap between each board. Some specially treated plywoods such as plastic coated or bitumen impregnated boards do allow vapour to pass through them and are therefore not suitable for the non ventilated use of breather membranes.