Envelopment tray for use with stone, concrete and jointed solid sills.
Bespoke Undersill Envelopment Trays provide the requisite damp proof course (DPC) presence in and around stone, concrete and jointed solid sills when incorporated within cavity wall construction.
Manufactured from solid polypropylene, trays extend up the back and ends of the sill, and pending the construction detail, return either immediately under or a course below the sill base.
Envelopment ensures DPC interruption to block damp permeation as defined within NHBC 6.1-S4 d: ‘Where a jointed or permeable sill is used (all sills in Northern Ireland and the Isle of Man), a DPC should be placed between the sill and the outer leaf, turned up at the back and ends of the sill.’ LABC/ Premier Guarantee 7.4.13.
Misplacement and DPC distortion can be eliminated using preformed Envelopment Sills that ensure the protective inclusion is consistent in shape and functionality. The tray end upstands cannot sag like flexible material and permit the reveal closing arrangement to positively integrate.
Envelopment Sills can be supplied incorporating a thermal break bonded to the rear of the cavity upstand. This option can be appropriate where there is no cavity wall insulation present. Envelopment Undersill Trays are supplied to customers dimensions.
The tray can finish flush with the exterior face or project forward of it in the form of a small lip as defined in LABC/ Premier Guarantee 7.4.13. State option required.
Where movement provision is required, soft infilling pointing is commonly recommended in a sill bed course and a projecting lip can assist soft pointing location and retention of such pointing.
Forticrete and other cast sill manufacturers sometimes recommend a slip-plane is incorporated with their products to accommodate possible (thermal co-efficient) movement. Where the specialist reconstructed stone sill supplier makes this recommendation, consideration may be given to using a cavitray slip-strip to accompany the Envelopment tray. The slip-strip is laid into the base of the tray and has one textured face and one smooth face to provide the requisite relationship. Consult manufacturer for further details.
Features and benefits:
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F30/270 Meshwork joint reinforcement
F30/56 Preformed cavity trays
Type U Envelopment Tray
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Standard product features