GB2480466A

GB2480466A - Secondary glazing sash stop

Info

Publication number: GB2480466A
Application number: GB201008352A
Authority: GB
Inventors: Adam Wladyslaw Wiktor Dudley
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-05-19
Filing date: 2010-05-19
Publication date: 2011-11-23
Also published as: GB2480514A; GB2480514B; GB201008352D0; GB201021738D0

Abstract

A detachable sash stop 13 is integrated into a secondary glazing unit which is attached on the interior side of a traditional sash and case window to improve the thermal insulation of the building. The outer frame 12 of the secondary glazing is located behind the window linings of the original window frame which have been moved outwards (cf. Fig 1) and a new insulation zone 10 has been inserted behind the original window shutters or panels 1. A packing zone 8 is also inserted under the architrave 6. The secondary glazing can be opened and the glazing sash stop 13 removed thus allowing the window batten rod 14 to also be removed. This permits the sash and case window to be opened and rotated as normal for cleaning, airing of the building etc. The removable sash stop can be removed using a proprietary socket key. Two embodiments of the removable sash stop are disclosed.

Description

SECONDARY GLAZING SASH STOP

This invention relates to a device integrated into a secondary glazing unit, and a process for installing the modified unit so that it maintains the full function of traditional timber sash and case windows, enables the secondary glazing to be fitted so that it preserves the various features of the existing sash and case windows and linings, and facilitates the thermal improvement of not only the existing window (by virtue of the secondary glazing) but also of the adjacent building fabric.

Approximately 20% of the current total housing stock in the UK is made up by pre-1920's buildings, and the vast majority of these properties have traditional timber sash and case windows. Timber sash and case windows are also predominant in other pre-1920's building types. With the current government targets for reducing carbon emissions by 42% by 2020, and by 80% by 2050, owner I occupiers of pre-1920's properties with traditional timber sash and case windows are becoming increasingly aware of the heat loss through their windows. Various methods for improving the thermal efficiency are being adopted. Some of these are better than others in terms of their performance, with secondary glazing achieving the highest reduction in heat loss of up 75%, in comparison with double glazing which achieves around a 55% reduction. Other measures in the market can be counter-productive, such as draft proofing around the window sashes, which simply removes the trickle ventilation which is otherwise necessary for the benefit of the building fabric (as required under the current building regulations). The principal deficiency with all of the measures to improve the thermal efficiency of timber sash and case windows is that they do nothing to reduce the heat loss through the adjacent building fabric, specifically to those parts which are most inefficient in terms of their thermal resistivity, such as the window backs, elbows, reveals, and soffit.

The main problem with conventional secondary glazing, whether manufactured with timber frames or with extruded I cast sections, such as aluminium, steel, and upvc, is that they regularly interfere with the operation of specific features of the window. In addition to this, secondary glazing is often unsightly and incongruous with the traditional detailing, particularly where windows have shuttered or panelled reveals.

Where secondary glazing is fitted within the window frame, either against, or in place of the batten rods, the frame of the secondary glazing prevents the lower sash from being hinged back, where this is required for easy-cleaning purposes (for cleaning the outside of the glazing, from the inside).

There are systems available whereby the entire secondary glazing can be removed, by way of releasing mechanical or magnetic catches, but this can be rather cumbersome, if not potentially hazardous, particularly where large windows are involved.

Where secondary glazing is fixed to the front of the window case, between the window reveals, this invariably also fouls the easy-clean operation of the lower sash. This is generally the case regardless of whether the window reveals are traditional plaster on timber lathe or modern plasterboard on timber framing, plated with tongue & groove lining boards, or are adorned with timber panels or shutters. In most instances, the plane of the finish meets the face of the window case close to the inner corner, immediately adjacent to the batten rod. The net effect of this relationship between the elements is that there is generally insufficient clearance between the batten rods and the face of the reveal where it meets the window case for accommodating the frame of the secondary glazing without it fouling with the operation of the window. Where shutters are present the frame of the secondary glazing has to be fixed to the face of the shutter, immediately rendering them inoperative.

Moreover, where Listed interiors of historic buildings are involved, this ad hoc I plant-on approach is potentially ruinous to the integrity and aesthetics of the original detailing.

To overcome the shortcomings of conventional secondary glazing and to address the heat loss through the susceptible adjacent building fabric, the invention comprises a detachable sash stop to the secondary glazing unit, which can be compatible with all materials of manufacture. It is applicable to a wide range of standard window I reveal configurations, and provides the potential for extending the thermal upgrading works beyond the window opening into the adjacent fabric, with the capacity to create a complete thermal shield' to the external elevation of a given room I building. By concealing all or part of the outer frame of the secondary glazing unit behind the adjoining window linings and by integrating the operating gear within the frame and sash, the visual impact of the secondary glazing is reduced.

Preferably, the opening mechanism for the secondary glazing has concealed hinges and stays to further reduce the visual impact of the secondary glazing.

Preferably the operating handle for opening the secondary glazing is detachable, so that the handle can be deployed only when the position I operation of the sash is altered, and can be removed and stored elsewhere for the rest of the time, thereby further reducing the visual impact of the secondary glazing. This is of particular benefit where the interiors are of a sensitive nature, as in the case of Listed interiors.

Preferably, the operating gear to the secondary glazing incorporates a tilt mechanism, in addition to the turn (side hinged) mechanism, to enhance the versatility, utility, and visual appearance of the sash when it is opened for ventilation purposes.

Preferably, the mechanical fixings for the detachable sash stop for all of the materials used in the manufacture of the modified secondary glazing are operated using the same proprietary socket key, although the detachable stops may be secured by other means, using magnetic or friction catches,

for example.

Preferably, the glazing to the sash is double glazed, in order to maximise the thermal performance of the modified secondary glazed unit.

Preferably, the modified secondary glazing unit incorporates a trickle ventilation feature, although this may be provided by other means, by way of a fresh air grille/duct through the external wall below the window cill, for example.

Preferably, due to the process for installing the modified secondary glazing, all other elements of the internal window opening, and all accessible cavities behind the conterminous wall lining within the building façade, are fully insulated.

The invention will now be described solely by way of example, and with reference to the accompanying drawings, addressing the typical window reveal configurations, in terms of their materiality, their components, and their relationship with their corresponding windows. These typical configurations have been illustrated with 2 sets of drawings, covering the full range of typical window reveals and the different frame materials for manufacturing secondary glazing. Set A' focuses on timber framed secondary glazing for typical timber sash and case windows with shuttered, panelled, or otherwise decorative reveals. Set B' focuses on aluminium (or steel, or upvc) framed secondary glazing for typical timber sash and case windows with tongue and groove lining, plaster on timber lath, or plasterboard on timber framed reveals.

SET A' ILLUSTRATIONS -TIMBER FRAMED SECONDARY GLAZING FOR TYPICAL TIMBER SASH AND CASE WINDOWS WITH TIMBER SHUTTERS, PANELS, OR OTHERWISE

DECORATIVE REVEALS

Figure 1A is for reference I background information purposes only, and indicates the heat loss through a typical window, reveal, and through the adjacent building fabric. This is illustrated in sectional plan view (through both the window case / reveal, and through the panelled window back and elbow) and in elemental sectional view.

Figure 2A shows the modified secondary glazing fixed to the face of the window case, with the shutter (or panelling) components dismantled and re-fitted on new timber packing elements, with new rigid and injected insulation, and new cover plates/facings. This is illustrated in sectional plan view (through both the window case / reveal, and through the panelled window back and elbow) and in sectional view.

Figure 3A shows the operation of the modified secondary glazing in tilt and turn mode, with the detachable window stop maintaining full operation of the easy-clean feature of the lower window sash. This is illustrated in sectional plan views through the window case / reveal.

Figure 4A shows the sequence of operations for removing the existing window reveal components, installing the modified secondary glazing, installing new timber packing elements, insulating the window back, elbows, reveals, soffit, and the cavity between the internal wall lining and the external masonry -and thereafter re-fitting the existing window reveal components.

Figure 1A shows a typical arrangement, with the window shutters/panels 1, the window back 2, elbows 3, shutter/panel pockets 4, soffit panel 5, and architraves 6, all duly indicated. Figure 2A shows how these elements are dismantled and reinstated on new packing timbers 8, with new timber cover plates 9 and salvaged/new cill board 16, in precisely the same configuration as the original, so that the shutters / panels 1, are remounted on the frame of the secondary glazing 12, in exactly the same position that they were in when previously fixed to the window case 7.

Figure 2A shows that by relocating the entire window linings to a new plane, the frame of the secondary glazing 12 can be completely concealed, and the shutters/panels 1 can be reinstated without having any alterations carried out. By first removing the window shutters/panels 1, back 2, elbows 3, and soffit panel 5, direct access is gained to the parts of the building fabric which are in most need of improved thermal insulation (in addition to the windows themselves). A new, deeper insulation zone 10 is formed by relocating the window linings to a different plane, and introducing new packing timbers 8 so that rigid insulation can be fixed directly into the voids. The exposed cavities between the internal wall linings (generally plaster on timber lath, where refurbish works have not previously taken place) and the external masonry, make it possible to install blown / injected insulation into the cavity 11, by means of a lance gaining access to the wall areas around the window opening, via the head and sides.

Figure 3A shows the secondary glazing sash stop 13 detached from the rebate in the frame to facilitate removal of the batten rod 14, enabling the existing lower window sash 15 to swing inwards for cleaning the outside face of the glass. As indicated, under normal circumstances the detachable sash stop is secured to the secondary glazing frame by means of flush/concealed fixings.

Figure 4A shows how the method for installing the modified secondary glazing is part of a process for insulating other parts of the building fabric, with the potential of creating a complete thermal shield.

First the architraves 6 are removed, followed by the shutters/panels 1, window back 2, elbows 3, cill 16, and soffit 5. The new packing timbers 8 are then installed to create the insulation zones 10, into which rigid insulation is fitted. Blown / injected insulation 11 is then installed into the exposed/accessible cavity between the wall lining and the external masonry. The modified secondary glazing unit 12, with detachable stop 13, is then fitted, together with the new timber facings 9, and the process completed by refitting all of the elements previously removed and set aside. The disturbance to the existing fabric is confined largely to the joinery components, and providing that good practice is followed, there should be very little remedial works required on completion of the process, other than some minor decoration works, specifically to the window architraves and shutter pockets where new packing timbers and cover plates have been introduced.

When all elements of the original timber fabric are reinstated, with the installation of the modified secondary glazing, and with all other insulation works complete, the changes in the overall appearance of the window I reveal are minimal. Apart from the visible sash to the secondary glazing, there is only a modest increase in the depth of the window architraves.

SET B' ILLUSTRATIONS -ALUMINIUM (OR STEEL, OR UPVC) FRAMED SECONDARY GLAZING FOR TYPICAL TIMBER SASH AND CASE WINDOWS WITH TIMBER TOUNGE & GROOVE LINING, PLASTER AND TIMBER LATH, OR PLASTERBOARD ON TIMBER FRAMED

REVEALS

Figure lB is for reference I background information purposes only, and indicates the heat loss through a typical window, reveal, and through the adjacent building fabric. This is illustrated in sectional plan view (through both the window case / reveal, and through the window back and elbow) and in elemental sectional view.

Figure 2B shows the modified secondary glazing fixed to the face of the window case, with the window opening linings removed and refitted on new timber packing elements, with new rigid and injected insulation, and new/salvaged cover plates/facings. This is illustrated in sectional plan view (through both the window case / reveal, and through the panelled window back and elbow) and in sectional view.

Figure 3B shows the operation of the modified secondary glazing in tilt and turn mode, with the detachable window stop maintaining full operation of the easy-clean feature of the lower sash. This is illustrated in sectional plan views through the window case / reveal.

Figure 4B shows the sequence of operations for removing the existing window opening linings, installing the modified secondary glazing, installing new timber framing, insulating the window back, reveals, soffit, and the cavity between the internal wall lining and the external masonry -and thereafter renewing the window opening linings.

Figures 1 B shows a typical arrangement, with the plaster or tongue and groove linings to the window reveals 1, the window back 2, and soffit 5, all duly indicated. Figure 2B shows how these elements are removed and reinstated on new/existing timber framing, to create rebates to accommodate the secondary glazing. New timber packing 8 is fitted to the window back, as part of this process. By creating the rebates, the frame of the secondary glazing 12, fixed to timber packers 8, can be set back from the opening of the existing window case, and partially concealed behind the plaster or tongue and groove linings, and framed with new timber facings 9 and with the salvaged / new cill board 16.

Figure 2B shows that by removing the window linings to create a rebate, direct access is given to the parts of the building fabric which are most vulnerable to heat loss (in addition to the windows themselves). In the event of there being no insulation present to these areas, rigid insulation can be directly fixed in between the exposed voids at the reveals 1 and soffit 5. With the introduction of the rebate for the secondary glazing, new timber framing 8 is fixed to the window back 2, creating a deeper insulation zone 10. The exposed cavities 11 between the internal wall linings (generally plaster on timber lath, where refurbish works have not previously taken place), and the external masonry, make it possible to install blown! injected insulation into the cavity, by means of a lance gaining access to the wall areas around the window opening, via the head and sides.

Figure 3B shows the secondary glazing sash stop 13 detached from the pocket in the frame 12 to facilitate removal of the batten rod 14, enabling the existing lower window sash 15 to swing inwards for cleaning the outside face of the glass. As indicated, under normal circumstances the detachable stop is secured to the secondary glazing frame by means of flush/concealed fixings Figure 4B shows how the method for installing the modified secondary glazing is part of a process for insulating other parts of the building fabric, with the potential of creating a complete thermal shield.

Firstthewindowcill l6and skirting 17 is removed, followed bythe lining tothe reveals 1, thewindow back 2, and soffit 5. The new packing timbers 8 are then installed to the window back, and to the reveals/soffit as necessary (in the event of the existing reveals 1 and soffit 5 being formed in plaster on timber lath) into which rigid insulation is fitted. Blown / injected insulation 11 is then installed into the exposed/accessible cavity between the wall lining and the external masonry. The modified secondary glazing unit 12, with detachable stop 13, is then fitted, and the process completed by reinstating the joinery/plaster window linings. The disturbance to the existing fabric is confined largely to the skirting and the plaster or tongue and groove linings, which, in any event, require alteration work, in order to create the secondary glazing rebates. Providing that good practice is followed, the remedial works should be restricted to the reinstatement window linings, window cill, and skirting, followed by some localised decoration works to these elements.

Following the reinstatement of the window linings, with both the installation of the modified secondary glazing and all other insulation works, the changes in the overall appearance of the window / reveal are minimal, apart from the visible frame and facings to the secondary glazing.

Claims

Claims 1. A modified secondary glazing sash stop which enables secondary glazing to be neatly fitted into a wide range of window reveals to traditional sash and case windows, so that the full functionality of the window features are maintained, and the visual impact of the secondary glazing unit minimised.
2. A modified secondary glazing sash stop according to claim 1, in which the location of the outer frame of the secondary glazing to which the stop is fixed, enables the full reinstatement of the window reveals, without altering their appearance or, affecting their operation, as in the case of working shutters.
3. A modified secondary glazing sash stop according to claim 1, in which a section of the stop to one side of the frame is detachable, to accommodate the easy clean operation of the lower sash to the existing window.
4. A modified secondary glazing sash stop according to claim 1, in which the cut out in the frame to which the detachable stop is fitted does not encroach into the open area of the case of the existing window, so that the frame does not obstruct the operation of the lower window sash for easy clean purposes.
5. A modified secondary glazing sash stop with detachable stop according to claim 3, in which the stop is secured to the frame, under normal circumstances, by means of a concealed fixing, finishing flush with the inside face of the stop.
6. A modified secondary glazing sash stop, with detachable stop according to claim 3, in which the stop is removed using a proprietary socket key.
7. A modified secondary glazing sash stop according to claim 1, in which the outer frame of the secondary glazing to which the stop is fixed, is fitted directly to the face of the existing window case, where it can be concealed behind the window reveal finishes.
8. A modified secondary glazing sash stop according to claim 1, in which the procedure for installing the secondary glazing to which the modified stop is fixed, enables insulation to be installed to the adjacent building fabric.