GB2382129A

GB2382129A - A hearth installation for a domestic flue of prefabricated buildings

Info

Publication number: GB2382129A
Application number: GB0222548A
Authority: GB
Inventors: Danny Shute
Original assignee: DUNBRIK
Current assignee: DUNBRIK
Priority date: 2001-10-04
Filing date: 2002-09-30
Publication date: 2003-05-21
Also published as: GB0123798D0; GB0222548D0; IE20020792A1

Abstract

A hearth installation comprises a U shaped block split into two sections 60, 62 each having a leg 64 at right angles to first and second arms 66, 68. Arms 66 are located in channel guide members (50, fig 1) so that panels (28, 30, fig 1) can move relative to sections 60, 62 and thereby avoiding stress on the flue from shrinkage of the panel than if the panels were fixed to the sections 60, 62. Between arms 68 is a space 70 which is filled by mortar. Sections 60, 62 are similar but are of opposite hand and when fitted one is turned upside down relative to the other. Sections 60, 62 may not be of similar shape and legs 64 may be inclined relative to the arms 66, 68.

Description

Improved Flue System This invention relates to an improved flue system.

In the construction of buildings, especially domestic homes, it is usual to provide the building with a flue which leads from for example the room commonly called the living room or lounge, the idea being that the flue leads to a fireplace in which a fire can be provided.

Fires in living rooms can take many forms from an open coal fire to a back boiler gas fire.

The present invention is concerned with buildings which are provided with hearths to receive open fires, be they of coal, coke, wood or the like. Such a flue system is called a Class 1 system. The system comprises an open hearth, and a flue of sufficient dimension or capacity to accommodate burning fuel. In such a system, the hearth is made up of blocks arranged to form the hearth cavity, and this is topped with the flue blocks which extend from the hearth cavity up to the top of the building, where there is a chimney. The gaseous products of combustion pass up the flue and out of the chimney to atmosphere Currently, because of a shortage of skilled building labour, there is a tendency to construct what are termed"factory built"homes. This does not mean that the entire home is built in a factory, but that as much as possible is, and sections of the building, already constructed, are taken to the site for erection.

Typically in a factory built home, timber or steel frames, or wall panels are constructed in the factory, and are transported to the site.

To construct say the living room, which will usually be downstairs, the frames or panels for the walls are erected, and then the flue system will be installed relative to the frame or panels of that wall, such frame or panels being provided with or defining a suitable aperture for the fireplace.

Conventionally, the timbers or beams of the frame or the panels which flank the fireplace are pinned by screws or other means to the blocks used to form the flue system, but there is a disadvantage with this arrangement in that in time, the frame, especially if it is of timber, will shrink relative to the flue system, creating undesirable stresses in the timber frame. The same can happen if steel frames or wall panels of cementitious material is used.

The invention the subject of our co-pending UK patent application No. 0102777.0 (the prior application) aims to provide a means of overcoming this disadvantage and provides that a class 1 flue system is located relative to a frame or panels by means of channels which are specifically connected to the frame or panels, the flue block edges locating freely in the channels, enabling the known amount of shrinkage of the frame or panels to take place, with time, relative to the flue system without stress being place on the flue blocks or the edges of the flue blocks coming out of the channels.

Preferably, there is a frame and it is of timber.

Thus, when the timber frame is delivered to site, the channels may have already been connected thereto, or they may be connected on site. These channels, as will be appreciated, are located around the fireplace aperture in the timber frame, so as to be open inwards of the aperture, and as the flue system is built up, from ground level, so the edges of the blocks of the flue system are fitted into the

channels, with clearance, so as to be free therein, to enable frame to shrink relative to the blocks, without undue stress being placed on the blocks or the rest of the building.

The flue system is built up progressively, throughout the height of the building.

The channels may be of galvanised steel, and they are preferably connected to the timber frame by screws, pins or other means.

A problem arises in connection with the fitting of the hearth blocks in that these blocks are in are of U shaped channel section, with integral outward flanges at the ends of the limbs and it is these flanges which locate in the channels. The channels typically are in sections of 1.25 metres length, and therefore when the channels sections adjacent the hearth are in position, to install a hearth block, the fitter has to raise the block (a heavy concrete item) so that the flanges become aligned with the tops of the channels and then the blocks can be lowered into the channels. This is a strenuous, and hazardous operation.

As an alternative to this, as shown in the prior application, the hearth blocks are made in three sections, namely a U shaped central section, and two L shaped side sections. The longer arms of the L shaped sections lie respectively adjacent the outsides of the limbs of the U shaped central section, whilst the shorter arms locate in the channel sections.

This alternative enables the hearth blocks to be fitted without the entire mass of the blocks being raised and lowered but in providing three sections, is an expensive construction, and fitting is still not easy as three hearth sections have to be aligned and manipulated into position. Also it is not easy to place mortar (usual or

recommended practice) between the longer arms of the L shaped

I side sections and the outsides of the limbs of the U shaped central s section.

The present invention aims to provide an arrangement wherein the fitting of the hearth blocks into the channels is simplified, and the disadvantages of the known arrangements are obviated. Additional advantages are that the overall block size and therefore weight can be reduced.

The invention provides a method wherein at least one class 1 flue system hearth block is located relative to adjacent wall frames or panels by means of channels which are connected to the frames or panels, and which are in face to face arrangement at opposite sides of a hearth aperture, the flue block edges locating freely in the channels, enabling the known amount of shrinkage of the frame or panels to take place, with time, relative to the flue system without stress being placed on the flue blocks or the edges of the flue blocks coming out of the channels, characterised in that the or each hearth flue block is of U shaped cross section with the outsides of the tops of the limbs of the U shape having extension flanges for engagement in the channels, and further wherein the hearth block is made up of two sections of which at least one section includes an extension flange, one side limb of the U shape, and at least a part of the base of the U shape, the sections being adapted in defining the hearth block, to be located with a gap for mortar or the like filling between the sections.

Preferably, the or each hearth block is in two opposite handed Z shaped sections, which are placed in the hearth aperture in sequence by locating the end of a lower limb of the first section in one channel, and the lower end of the second section in the other channel, and then manipulating the sections so that the upper limbs

become aligned and side by side with a space therebetween for a filling of mortar or the like, thereby forming the hearth cavity, or a part thereof in the event that multiple further similar hearth blocks are required to create a hearth cavity of the required height.

The invention also provides a one class 1 flue system installation including at least one hearth block is located relative to adjacent wall frames or panels by means of channels which are connected to the frames or panels, and which are in face to face arrangement at opposite sides of a hearth aperture, the flue block edges locating freely in the channels, enabling the known amount of shrinkage of the frame or panels to take place, with time, relative to the flue system without stress being placed on the flue blocks or the edges of the flue blocks coming out of the channels, characterised in that the or each hearth flue block is made up of two sections of which at least one section includes an extension flange, one side limb of the U shape, and at least a part of the base of the U shape, the sections being adapted in defining the hearth block, to be located with a gap for mortar or the like filling between the sections.

Preferably, the or each hearth block is in two opposite handed Z shaped sections, which are located in the hearth aperture with the end of a lower limb of the first section in one channel, and the lower end of the second section in the other channel, and the upper limbs of the respective sections being aligned and side by side with the space therebetween filled with mortar or the like, thereby forming the hearth cavity, or a part thereof with multiple further similar hearth blocks similarly located in the channels providing the remainder of the hearth cavity.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings wherein, Fig. 1 is a sectional plan of a building wall at the fireplace recess level showing flue blocks of the type set forth in the prior application ; Fig. 1A is a view similar to Fig. 1, but showing the flue blocks as used in the present invention ; Fig. 2 is a sectional plan of the building wall at a position above the shoulders of the flue; Fig. 3 is a sectional side elevation through the wall the section being taken on the centre of the fireplace; Fig. 4 is a front elevation of the wall showing the fireplace (which is in accordance with the prior application arrangement; and Fig. 5 is an enlarged sectional plan of the channel and block connections in Fig. 1.

Referring to the drawings, and firstly to Fig. 4, a domestic flue system (as set forth in the prior application) is indicated generally by reference numeral 10, and is provided with the class 1 hearth arrangement 12 in which any appropriate materials may be burned.

The hearth cavity 20 is made up of three superimposed and similarly shaped U hearth blocks 14,16 and 18, each of U channel shape as shown by block 16 in the sectional view of Fig. 1.

The sides of the blocks 14 to 18 are flanked by hearth flanking blocks 22,24 and 26 which again as shown in Fig. 1 are of L-shape in cross-section, each block having a long leg which lies adjacent the hearth block, and a short leg which extends at right angles to the sides of the hearth blocks so as to lie in effect in alignment with the wall panels 28 and 30 forming the interior wall of the room.

Exteriorly, there is brickwork 32, and this brickwork as is common in building construction is spaced from the inner wall panels 28 and 30 to provide an insulating air gap 34. The brickwork 32 follows the shape of the hearth 12 as shown in Fig. 1 and also in Fig. 2.

On top of the hearth blocks 14 to 18 there is mounted a hearth throat block 36 the purpose of which is to narrow the flue passage from the width of the hearth cavity 20 down to the size of flue liners 38 of circular configuration as shown in Fig. 2.

The throat block 36 is flanked by flanking blocks 38 and 40 of a similar configuration to blocks 22 to 26, and the short legs of the blocks 38 and 40 align with the short legs of the blocks 14,16 and 18.

Above the throat block 38 is a series of flue blocks 42 which are of a configuration shown in Fig. 2 in that they are square hollow form provided with an extension leg 44, and up the height of the flue stack these blocks 42 are placed alternately as shown in Fig. 4 so that the legs 44 in respect of adjacent blocks, face in opposite directions.

Finally, flanking blocks 46 and 48 which respectively are long and short are placed adjacent the flue blocks 42 as shown in Figs. 2 and 4.

The ends of the blocks 46 and 48 align with the ends of the short legs of the hearth flanking blocks 22 to 26, and the throat flanking blocks 38 and 40. The reason for this is that these edges locate freely in guide channels 50 and 52 which are in channel section lengths connected to the wall panels 28 and 30 as shown in Fig. 1.

This means that the portions of the flanking blocks which engage in the channels 50 and 52 are free to move relative to the channels, whereby when the shrinkage as mentioned herein takes place, stresses between the blocks which engage in the channels and the channels themselves, and hence the wall panels are avoided.

The wall panels suitably are made up of frames of timber, and may be in filled with insulating or finishing material such as cementitious material to form the wall panels 28 and 30, as described herein.

Plaster board or the like is finally placed over the panels on the inside surface and over the flue blocks located above the hearth.

The detail concerning the connection between the blocks and the channels is shown more clearly in Fig. 5, where the timber frame member adjacent the channel 52 is shown and is indicated by reference numeral 54, and that frame member is pinned or otherwise secured to the channel 52 but the short leg 56 of the flanking block 40 is free to move in the channel 52 to provide the improved effect of the invention as mentioned in the said prior application.

As shown in Fig. 4 the flue blocks 42 are built up to as high a level as required until the chimney 58 is reached. In construction, the wall panels 28 and 30 are initially put in place, and the flue is built up progressively from the bottom. As the flue liners 38 are placed in position in each of the upper blocks 38 and 42, the space around the flue liner may be filled with appropriate insulating backfill material. The flanking blocks are placed so that their portions in

alignment with the wall panels are engaged in the channels as described herein.

With the construction so far described, the disadvantages mentioned herein are present. By having the hearth blocks in three sections, fitting is inconvenient and by virtue of the design, the minimum size of the hearth and flue is limited, resulting in the use of a greater amount of flue block material.

The arrangement according to the invention overcomes these disadvantages, and one embodiment is shown in Fig. 1A, to which reference is now made.

As shown in Fig. 1A, the three sections of hearth block are replaced by two sections 60 and 62 of Z shape. The leg 64 of each Z block is at right angles to the arms 66 and 68, but they may be inclined relative to said arms. In the example, the respective Z blocks are similar but of opposite hand and as they are of constant cross section, they may be made in the same mould so as to be identical, but when fitted one is turned upside down relative to the other one.

This is the most desirable arrangement, but it is not necessary that the block sections should be identical.

An advantage of using the Z shaped blocks is that the blocks can be positioned in the channels without having to be lifted to the top of the channels or channels sections, and then lowered into the channels/channels sections. This is achieved by fitting the lower or outer arm 66 of the first block section into the one channel section, followed by fitting the lower or outer arm 66 of the other block section into the other channel section, followed by the manipulation of one or both block sections 60,62 into the final position shown.

As only two block sections 60 and 62 are used then the hearth can be made smaller, and lighter block sections can be used. When fitted

the arms 68 of the respective block sections are aligned and the hearth cavity 20 is defined by the legs 64 of the blocks and the aligned higher or inner arms 68 of the blocks, the space 70 between the ends of arms 68, for the receipt of mortar or the like filling, being designed to be as small as possible.

The or each hearth block need not be of Z section, but two non identical parts can be used to make the same hearth block shape.

This means that at least one part will be required to be made up at least of one of the flanges, one of the U shape limbs, and at least a part of the base of the U shape. For example, the two parts may comprise a Z section part and an L section part, or two Z section parts which are not identical. The parts of the block can be fitted in the same manner as the identical Z shaped parts described and illustrated above.

In the finished flue, as it is a class 1 flue, it would be usual to

provide a liner for the hearth, to prevent products of combustion provi from leaking out of the flue rather than be being discharged from the chimney at the top of the flue.

A particularly suitable and effective construction results, in that in all embodiments of the invention, the flue can be constructed simply and quickly, and the hearth blocks can be made smaller and lighter resulting in a reduction in expense. Also, the blocks being used in conjunction with the channels as in the prior application, stresses between the wall panels and their frames and the flue stack are avoided.

Modifications may be made without departing from the scope of the invention as explained herein.

Claims

1 A hearth instalation wherein at least one class 1 flue system hearth block is located relative to adjacent wall frames or panels by means of channels which are connected to the frames or panels, and which are in face to face arrangement at opposite sides of a hearth aperture, the flue block edges locating freely in the channels, enabling the known amount of shrinkage of the frame or panels to take place, with time, relative to the flue system without stress being placed on the flue blocks or the edges of the flue blocks coming out of the channels, characterised in that the at least one hearth flue block is of U shaped cross section with the outsides of the tops of the limbs of the U shape having extension flanges for engagement in the channels, and further wherein the hearth block is made up of two sections of which at least one section includes an extension flange, one side limb of the U shape, and at least a part of the base of the U shape, the sections being adapted in defining the hearth block, to be located with a gap for mortar or the like filling between the sections.

2. A hearth installation according to claim 1, wherein the at least one hearth block is in two opposite handed Z shaped sections, which are placed in the hearth aperture in sequence by locating the end of a lower limb of the first section in one channel, and the lower end of the second section in the other channel, and then manipulating the sections so that the upper limbs become aligned and side by side with a space therebetween for a filling of mortar or the like, thereby forming the hearth cavity, or a part thereof in the event that multiple further similar hearth blocks one on top of each other are required to create a hearth cavity of the required height.

3. A hearth installation substantially as hereinbefore described with reference to the accompanying drawings.

4. A method of installing the system according to claim 2 or 3, wherein respective sections are located in the hearth aperture with the end of a lower limb of the first section in one channel, and the lower end of the second section in the other channel, and the upper limbs of the respective sections being aligned and side by side with the space therebetween filled with mortar or the like, thereby forming the hearth cavity, or a part thereof where multiple further similar hearth blocks are similarly located in the channels and arranged one on top of another to provide the remainder of the hearth cavity.

5. A method of installing a hearth substantially as hereinbefore described with reference to the accompanying drawings.