Polycomp Products Limited

PART 1 - INTRODUCTION

Polythane is a PIR (polyisocyanurate) insulation board intended for use in masonry walls with partial fill cavity insulation. Polythane consists of a core of PIR foam bonded on both faces to composite aluminium facings; the gas filled cells give Polythane its high thermal performance and strength. The thermal performance of masonry cavity walls depends largely upon the insulation used within the cavity. It is becoming increasingly difficult for designers to achieve the lower U-values imposed by regulations while maintaining the nominal 40 - 50mm clear cavity needed to prevent moisture reaching the inner leaf of the wall. Thanks to its low thermal conductivity, Polythane minimizes the thickness of insulation needed within the cavity to give the required thermal performance, in most cases avoiding the need to have a cavity greater than 100mm wide.

PART 2 - TECHNICAL CHARACTERISTICS

2.1 Design Notes

• to prevent moisture transferring to the inner leaf, a clear cavity must be maintained. In most situations a 40 - 50mm clear cavity will be required, but some locations and constructions may allow that to be reduced.
• wall ties should be double triangle, vertical twist or to DD140-2 and spaced at 750mm horizontal centres and 450mm vertical centres. Additional ties will be required around openings.
• wall insulation must extend 150mm below upper edge of floor insulation to prevent thermal bridging.

2.2 KEY PROPERTIES

PART 3 - INSTALLATION

1.1 Installation Guidance

1. Set the first row of wall ties at 750mm centres, build up the inner leaf by 450mm; all cavities to be kept clean.
2. Set the second row of ties at 450mm centres.
3. Fit Polythane boards between the ties, so each board is supported on two ties. Butt the boards together tightly.
4. Clip discs or collars onto the ties to hold the boards tight against the inner leaf.
5. Raise the outer leaf by 450mm: use a cavity board to protect the cavity from mortar droppings.
6. Repeat the sequence to the top of the wall.

If the cavity includes a radon barrier the foot of the first run of boards will be supported on the cavity tray.

Head - rebated frame	Jamb - rebated frame
Cill - rebated frame	Jamb - flush frame
External corner	Internal corner

1.2 Notes

• At corners butt boards tightly together.
• Butt Polythane boards neatly to the backs of frames, cills, cavity closers and lintels.
• Ensure wall ties slope down from the inner leaf to shed water into the cavity.

PART 3 - HANDLING AND STORAGE

Polythane boards are supplied in shrink-wrapped packs. Store boards under cover and out of direct sunlight, keeping boards flat. When handling Polythane do not knock corners and edges.

Cut Polythane with a fine tooth saw or trimming knife.