Insulated Reveal
Preventing thermal bridging at reveals is a problem with cavity
wall construction. This is a quick and easy solution.
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Blockwork inner leaf |
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Polyfoam Cavityboard |
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Clear cavity |
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Polyfoam System Closer or Polyfoam Combi Closer |
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Plaster finish covers Polyfoam Cavity Closer |
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Flexible strip to closer acts as backing to sealant |
Products
- Polyfoam System Closer comprises Polyfoam high performance,
100% ozone friendly, extruded polystyrene, rigid board insulation
semi-enclosed in a rigid PVC casing.
- Polyfoam Combi Closer is a variant of System Closer,
dimensioned to fit a range of cavity widths.
Typical Construction
Polyfoam System Closer and Polyfoam Combi Closer are located
between inner and outer leafs of masonry cavity walls at window and
door openings in place of the traditional blockwork return.
The Polyfoam closers fully fill the cavity and provide a damp
proof barrier between the inner and outer leaves. The casing and
the Polyfoam core are both highly moisture resistant. The casing
has a flexible strip attached to fit into the rear of door and
window frames to act as an extra damp-proof seal.
Polyfoam System Closer is available in standard sizes to suit
50, 65, 75, 85 and 100mm cavity widths. Polyfoam Combi-Closer is
available in 75 and 100mm and can be adjusted on site to fit a
range of cavity widths.
Performance
Thermal performance
Polyfoam System Closer and Polyfoam Combi Closer have a
thermal conductivity of 0.030 W/mK and can easily achieve the
requirements of the Building Regulations for preventing thermal
bridging at openings.
Fire performance
Polyfoam System Closer and Polyfoam Combi Closer contain a flame
retardant to inhibit localised ignition. When contained within a
cavity wall behind a plaster or similar finish they will not
prejudice the fire resistance of the wall.
Installation
The closers are simply cut to length with a normal hand saw.
Care should be taken to ensure a tight fit. The jamb closer should
overlap the sill closer and butt up to the underside of the
insulated lintel.
Any off-cuts can be utilised by simply pushing the insulating
foam core upwards so that it protrudes from the end of the plastic
casing. The casing of another piece is then slid over the
insulating core, joining the two pieces together.
The ties, if used, are installed at 500mm centres and built in
as work proceeds. Alternatively, the flanges of the closer can be
nailed in position at about 450mm centres.
All Residential Masonry Cavity Wall Solutions