Vapour barriers, separation & filter layers
The lifespan of roofing waterproofing systems can be maximized by the control or elimination of vapour from within insulated roofing systems.
All designs should be checked in terms of condensation risk for the intended building function prior to the specification and installation of any system. Polisystem UK ’s technical department can advise on the best method at the design stage. Polisystem vapour control layers can also help towards the air tightness of buildings.
- Polythene VB
- Bituminous VB
- Separation & Filter Layers
Polisystem Polythene Vapour Barrier & Lap sealing tapes (NEW BUILD)
Polisystem Polythene Vapour Barrier 250µ
| Dimension 25m x 4m | Thickness 250µ | Weight 25Kg |
Polisystem Foil Tape
For use with item above & insulation boards where applicable.
Type T-F3004SP
| Dimension 50mm x 45m | Thickness n/a | Weight 0.5Kg |
Polisystem Polythene Vapour Barrier restricts the passage of warm, moist air from within the building from permeating into the structure or the roof. It is generally used on roofs with either a timber or metal deck and is installed loose with 100mm overlaps which should be sealed using Polisystem Foil Tape.
Polisystem Polythene Vapour Barrier should be installed on the "warm" side of the insulated structure, with special care being taken to ensure that all seams and holes are sealed effectively - thus rendering the whole structure moisture vapour proof and improving thermal performance.
It is important that Polisystem Polythene Vapour Barrier should be continuous in order to prevent vapour entering the wall or the roof.
Polisystem Polythene Vapour Barrier is manufactured to NHBC standard (Clause 6.2) using virgin polyethylene.
Polisystem Bituminous Barrier & Primers (NEW BUILD & REFURBISHMENT)
Polisystem Bitumen Primer 25 litre can
Betagum V2Kg SBS Underlay
Vapour Control layer
pe/sand finish
Glass reinforced
Betagum V3Kg SBS Underlay
Vapour Control Layer
pe/sand finish
Glass reinforced
Scudovapor SBS 4mm Vapour Barrier
pe/sand
Metal lined
Polistick Self-Adhesive Bitumen 3mm
Polyester Reinforced
Polisystem Bituminous Barrier is recommended for buildings with a high humidity rate such as laundries, swimming pools, and highly air-conditioned buildings - for instance buildings which belong to inside climate class IV.
The Polisystem Bituminous Barrier is applied onto the roof deck before the laying of the insulation to avoid condensation in the insulation. An aluminium sheet is the core of Polisystem Bituminous Barrier. This sheet, centred in the membrane, is coated on both sides with plastomer-bitumen blend. The polymers used are noble atactic polypropylene.
The top side of Polisystem Bituminous Barrier is covered with sand and the underside with a thermofusible film.It is recommended to apply Polisystem Bituminous Barrier in full adherence by torching.
Separation Layers & Filter Layers (GEOTEXTILES)
Polisystem Geotextile HP32 (240gm)
For smoothing & protection
Polisystem LO-K
For anti-cooling with inverted roofs using
XPS insulation and gravel protection
With the advent of ISO 6946:1996/And 1:2003,
the calculation for the water cooling effect in an
inverted or protected membrane roof has changed
dramatically. This new CEN must be adhered to
and therefore the percentage adjustment to the
thickness of extruded polystyrene board increased
accordingly.
What does this mean?
The old method required a 20% adjustment to the thickness of the extruded polystyrene boards for a given U value calculation. For example, if under normal calculations 120mm of extruded polystyrene gave a U value of 0.25Wm²/K then 20% or 24mm had to be added to the board, to counteract the water cooling effect. In real terms the board thickness would be chosen with the product limitations i.e. the nearest thickness to 144mm would either be 140mm, 150mm or 160mm.The new calculation or CEN requires that the rate of precipitation should be based on the location of the project. This means that, using the new calculation, a project requiring a U value of 0.25Wm²/K in London will require a 25% adjustment to the thickness where as the same type of project and U value in Glasgow will need a 50% adjustment. The thickness requirements are as follows: 150mm in London and 180mm in Glasgow. These examples are the extremes for the UK. Lo-K (EPMS) will alleviate the large percentage increases required.
Polisystem Polyproplene Filtex 1000
For gravel protection
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