This invention relates to cavity closer apparatus especially, but not necessarily, for use with insulated concrete form (ICF) walls.
ICF walls are increasingly being used not only for construction of domestic buildings but also for larger commercial structures and are particularly beneficial in environmental terms in providing high levels of heat insulation; walls can also be erected much faster than with traditional construction methods. ICF walls comprise inner and outer leaves formed from expanded polystyrene blocks held in place by webs moulded into the polystyrene to define a cavity which, after addition of appropriate steel reinforcement, if required, is filled with ready-mixed concrete. The exterior surface of the polystyrene blocks can be coated with brick slips or other cladding for decorative purposes. The interior surface of the inner leaf can be covered with plasterboard and decorated, in the conventional manner.
Before pouring the concrete, it is necessary to close the exposed cavity around window and door openings and, for this purpose, GB 2397588 describes a cavity closer including an adjustable window/door frame fixing system which accommodates frames of different sizes and incorporates a raised housing on which the window or door frame engages and behind which are integrally-formed recesses to receive female carriages which selectively, for adjustment purposes to accommodate different depths of frame, can receive male projections formed on the underside of a locking member which includes a resilient seal to abut the inner surface of the frame. It has been found in practice, however, that such arrangements have certain disadvantages. For example, the raised housing effectively creates a void under the external sill; additionally, the locking member is adjustable only incrementally, according to the spacing of the male/female interlockable parts, the resilience of the seal being relied on to fill the remaining small gap between the locking member and the frame.
It is an object of the present invention to provide a cavity closer which overcomes the disadvantages of currently-available apparatus.
In one aspect, the present invention provides cavity closer apparatus in strip form and suitable for use with ICF walls, the apparatus comprising a body member including a central portion for bridging the cavity between inner and outer wall leaves and respective front and rear projections for engaging the exposed ends of the leaves, in use, in which the body member incorporates means for lockable engagement of fixing cleats for a window or door frame.
Preferably, the central portion of the body member includes a housing defining one or more voids containing insulation material, the respective front and rear walls of the housing being sized to fit within the cavity of the wall to prevent cold bridging. Conveniently, the underside of the central portion, or the bottom wall of the insulation housing, includes integral formations which, in use, become embedded in the wet concrete as it is being poured and which, after the concrete has cured, lock the body member permanently in place against the edge of the door or window opening.
The fixing cleats preferably comprise clips formed from a flat strip of springy or resilient material, preferably metal, adapted at one end portion (the forward end) for attachment to a door or window frame element and at the other (rearward) end portion for lockable engagement with the body member, behind the frame element, whereby the frame can be inserted from the interior of the building and locked in position from the inside. Preferably, the fixing cleats are snap-engageable in longitudinal channels formed in the body member. In a more preferred arrangement, the body member includes two or more longitudinal channels, so that a selected channel may be used for engagement of the fixing cleat according to whether the frame is required to be positioned relatively forwardly or relatively rearwardly in relation to the wall opening. By way of example, for lockable engagement by snap action, the rear or tail end of the fixing cleat may have a U formation and the longitudinal channel may have a projection overhanging its rear wall, the limbs of the U formation being resiliently inwardly compressible on insertion within the channel and the distal or free end of the U formation lockably engaging under the overhang. The fixing cleat preferably has an intermediate portion, between the end portions, which passes beneath the rear wall of the frame, thereby locking the frame in its desired position when the cleat is engaged with the body member.
Where the lower element of the frame is formed as or includes a sill, either a window sill or a door sill, the element is attached direct to the body member of the cavity closer apparatus in the manner described. However, where the wall cladding, for example, brick slips, is intended to extend around the reveal of the window or door aperture, to simulate a wall constructed from traditional bricks, it is necessary for the head and side elements of the frame to be spaced from the top and sides or jambs of the opening by an amount equivalent to the depth of the brick slips. Accordingly, the apparatus according to the invention also includes a spacer member in strip form, the body and spacer members including means for mutual engagement at a desired position relative to the depth of the body member, the spacer member including means for lockable engagement of fixing cleats for the window or door frame. Thus, the spacer member, which preferably is also formed as a housing defining a void containing insulation material, may be formed with a longitudinal channel in like manner as that formed in the body member, for lockable engagement of fixing cleats for the frame in the same way as already described for direct attachment of the frame to the body member. For mutual engagement purposes, the body and spacer members may be formed with interlockable or interengageable projections/recesses which, for example, may be formed as cavities in one member and projections formed on the other member for engagement in the cavities, preferably with a force or interference fit, or as a longitudinal groove formed in one member for receipt of a corresponding longitudinal ridge or projection formed on the other member, preferably having a dovetail cross section for retention purposes. Preferably, the mutual interengagement means are provided for selective positioning of the spacer member relative to the body member, again according to the desired position of a frame relative to the depth of the wall.
Apparatus according to the invention preferably further includes an elongate stop member, attachable to the spacer member, to provide a forward abutment for the frame when placed in position from the interior of the building. The stop member may comprise an L member in cross section and the front upper part of the spacer member may be formed with a recess to accommodate the base part of the L; the stop member and the spacer member may be formed with interlockable projections similar to those of the body and spacer members.
Using apparatus according to the invention, the fixing cleats may be attached to the window or door frame at any position to provide a snug location of the frame, following engagement of the cleat to the body member or spacer member, against the stop member, irrespective of the depth of the frame elements, requiring to be sealed only by an external mastic sealing strip.
Apparatus according to the invention can be formed from re-ground PVCu plastics material, insulation material within the housing comprising a phenolic foam material. The body member, spacer member and stop member may be supplied in strip form to be cut, mitred, folded and glued on site according to the dimensions dictated by the window and door dimensions.
Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, of which:
With reference firstly to
The spacer member 11 has a base 31, front wall 32, a rear wall 33 and a top wall 34 defining a housing also containing a rigid insulation material. A rear extension 35 defines, together with rear wall 33, a channel 36 shaped and dimensioned essentially the same as the channels formed in the body member 10. The base 31 is formed with a depending longitudinal ridge 37 with a dovetail shape to engage in a selected groove 30 formed in the body member 10. The front portion of the top 34 is formed as a recess or rebate 38 itself formed with a dovetail groove 39.
The stop member 12 has an L cross-sectional shape with a base 40 and an upstanding front wall 41. A dovetail ridge projection 42 is formed below the base 40 for engagement in groove 39 formed in the spacer member 11.
With reference to
In
With reference to
Typically, spring clips are spaced at 300 mm intervals along the body or spacer members, for attachment of the frame elements.
With reference to
Number | Date | Country | Kind |
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0703270.9 | Feb 2007 | GB | national |