GB2382130A

GB2382130A - A gas flue assembly with laterally spaced supports with guide means

Info

Publication number: GB2382130A
Application number: GB0225608A
Authority: GB
Inventors: Robert Burke
Original assignee: Red Bank Manufacturing Co Ltd
Current assignee: Hanson RBMC Ltd
Priority date: 2001-11-03
Filing date: 2002-11-04
Publication date: 2003-05-21
Anticipated expiration: 2022-11-04
Also published as: GB2382130B; GB0225608D0; GB0126487D0

Abstract

A gas flue system 10 comprising a pair of laterally spaced apart supports 12, a flue stack 14 disposed between the supports and a guide means 26 disposed between the supports and the flue stack, wherein, the stack includes a plurality of superposed blocks 16 adapted to at least partially receive the guide means 26. Preferably the blocks 16 are rectangular, of U-shaped cross-section and comprise three layers. The blocks 16 may have projections 28 and recesses 30 on the external side walls. The guide means may have two limbs, parallel to each other and offset by a third limb, the first limb being for attachment to the support 12, the second to be received by recess 30. Preferably the guides are galvanised steel and supports are made from timber studs or steel. A cover block 20 (fig 3) with a tapered bore may be located directly above blocks 16, above which may be a plurality of courses comprising laterally alternating flue blocks 22 (fig 4) and flanking blocks 24 (fig 5).

Description

TITLE: Gas flue system The present invention relates to a gas flue system, more particularly, but not exclusively, to such a gas flue system for domestic, timber frame buildings.

It is known to install a gas flue system in a house or other building, to provide a flue passage through which the products of combustion from a gas appliance can be expelled.

A known gas flue system consists of superposed pre-cast concrete flue blocks, each having an internal passage extending vertically through the block, the internal passages being in alignment with one another to create a flue passage. The flue blocks are assembled on a plurality of pre-cast concrete starter blocks of substantially U-shaped channel cross-section, which provide a suitable recess for receiving a typical gas appliance. A concrete cover block, also known as a lintel block, is provided intermediate the starter blocks and flue blocks, and has a tapered internal passage, which provides a lead passage for combustion gases into the flue passage from an appliance installed in the recess. Hence, the flue blocks, cover block and starter blocks form a flue stack for expulsion of the products of combustion from a gas appliance. An exit block may be provided on the uppermost flue block, which provides a terminal for connection to a metal exit flue pipe. A bonding compound, commonly a fireproofmortar, is applied between each course of the flue stack, to provide an airtight seal within the flue passage.

When installed in a timber frame building, the flue system is assembled between two laterally spaced vertical timber studs, for example as part of an external or internal wall. The flue system further comprises of a vertical galvanised steel U channel affixed to each stud with the open region of each channel facing the opposed channel. Each U channel comprises two parallel limbs spaced at a distance corresponding substantially to the width of the flue stack. The flue stack, substantially as described above, is assembled between the limbs of the U channels, which provide lateral support for the flue stack.

The U channels are provided in 1.2 m lengths and are fixed in place as the work progresses, starting from the base of the system. During assembly of the gas flue system, it will be appreciated that each course of the flue stack has to be lowered into position between the limbs of the U channels. Satisfactory positioning and bonding of the successive courses within the confined area of the U channels is problematic and requires a specialist tradesman, for example a bricklayer.

Incorrectly positioned or secured blockwork can have a negative effect on the structural integrity of the flue system. This problem can be exacerbated at the top of a building, for example, where there may not be sufficient space to gain access through the top o f the U channels, in which case the uppermost blocks may not be securely positioned or supported.

Further, it is common for the U channels to become deformed, either during movement to a site or during construction of the flue system, for example if a U channel is struck by a heavy object. If the parallel limbs of a U channel are deformed, for example if the limbs are directed inwardly or include a constriction or inwardly disposed dent at any position along the length of the U channel, it may not be possible to lower the flue blocks down between limbs of the U-channel into the required position on the flue stack. In such an instance, it is therefore necessary to remove the flue block from between the limbs and straighten or reconfigure the deformed area to the original shape of the U-channel. In some cases, it maybe necessary to deconstruct a whole section of the flue stack in order to replace a deformed U channel, which can be time consuming.

It is an object of the invention to reduce, or substantially to obviate, the disadvantages of conventional gas flue systems for use in timber framed buildings referred to above.

According to the present invention, there is provided a gas flue system comprising a pair of laterally spaced supports, a flue stack disposed between the supports, and guide means disposed between the flue stack and the supports for aligning the flue stack, the flue stack including a plurality of superposed flue blocks defining a flue passage, in which the flue blocks are adapted to at least partially receive the guide means, and the guide means are at least partially received by the flue blocks, thereby aligning the flue stack and providing lateral support thereto.

Preferably, the flue blocks are generally rectangular and include a formation for at least partially receiving the guide means the formation.

The formation may be in the form of a projection on the side of the flue block.

In a preferred embodiment, the flue blocks include a formation in the form of a recess on the side of the flue block, in which the a respective guide means is at least partially received.

Conveniently, the recess is substantially U-shaped.

The guide means may include a limb which is at least partially received by a respective flue block.

Further, the guide means may include a limb for connecting to a respective support Preferably, the guide means include a first limb which is at least partially received by a flue block at each course of the flue stack, and a second limb which is connected to a respective support.

Preferably, the first and second limbs are off set by a third limb transverse to the first and second limbs.

In a preferred embodiment of the invention, each flue block includes a recess having a width w and a depth d, and the guide means include a free limb and a transverse member, the free limb corresponding substantially in length to the width w and the transverse member corresponding substantially in length to the depth d, such that the free limb is received in the recess and the transverse member is at least partially received in the recess.

According to a further aspect of the invention, there is provided a method of assembly for a gas flue system, the method involving the sequential steps of : a) providing a pair of laterally spaced supports at a predetermined spacing from one another; b) providing guide means on each support, and

c) assembling a flue stack between the supports, the flue stack including a plurality of superposed flue blocks defining a flue passage, the flue blocks being adapted to at least partially receive a respective guide means, in which each course of flue blocks is placed into position in the flue stack with the guide means at least partially received by the flue blocks.

The system and method of assembly according to the invention overcomes the disadvantages of the known flue system for timber frame buildings, described above. The guide means provide a simple means for aligning and positioning each course of the flue stack, without the need for a specialist tradesman, e. g. a bricklayer, as will be apparent in the following description of the invention. Assembly of the gas flue system according to the invention is thereby simpler and more expedient than known systems for timber frame buildings.

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure I is a diagrammatic view from the front of an embodiment of a gas flue system according to the invention; Figure 2 is a perspective view of a starter block, as used in the embodiment of Figure l ; Figure 3 is a perspective view of the cover block shown in Figure 1 ; Figure 4 is a perspective view of a flue block, as used in the embodiment of Figure 1 ; Figure 5 is a perspective view of a flanking block, as used in the embodiment of Figure 1; Figure 6 is a cross-sectional view through line A-A in Figure 1; Figure 7 is a cross-sectional view through line B-B in Figure 1 ;

Figure 8 is a cross-sectional view through line C-C in Figure 1; Figure 9 is an enlarged view of the bottom right hand area of Figure 8; Referring firstly to Figure 1, an embodiment of a gas flue system according to the invention is indicated generally at 10. The gas flue system 10 includes a pair of laterally spaced supports in the form of timber studs 12, and a flue stack 14 assembled between the studs 12.

The flue stack 14 includes three superposed pre-cast concrete starter blocks 16, which create a suitable recess 18 for receiving a typical gas appliance. A pre-cast concrete cover block 20 is provided on top of the assembled starter blocks 16. The cover block 20 has a tapered internal passage (not shown) extending vertically through the block, to provide a lead passage for the combustion gases from an appliance (not illustrated) installed in the recess 18.

Aplurality of gas flue blocks 22, only two courses of which are illustrated, are stacked on top of the cover block 20. The flue blocks 22 each have an internal passage (not shown) extending vertically through the block, which are in alignment with one another to form a flue passage in alignment with the lead passage of the cover block 20. The flue stack 14 further includes a flanking block 24, as will be described below, provided at each course of flue block 22. As shown, the successive courses of flue/flanking block are disposed alternately, e. g. with the flanking block 24 in the first course disposed on the left hand side, as viewed in Figure I, and the flanking block 24 in the second course disposed on the right hand side as viewed.

A bonding compound (not shown), commonly a fireproof mortar, is provided between each successive course of the flue stack, to provide an airtight seal within the flue passage.

Galvanised steel guides 26 are provided on opposing faces of the timber studs 12, between the timber studs 12 and the flue stack 14, to provide lateral support for the flue stack 14, as wi 11 be described below.

The starter blocks 16 are each of rectangular U-shaped internal cross section, having a rear wall and two parallel sidewalls, as can be seen in Figure 2. Projections 28 extend from the external surface of the side walls, which form a recess 30 on each side of the starter block 16.

The cover block 20 is generally rectangular in plan view, as shown in Figure 3, and has a centrally located internal passage 32 extending through the block. The internal passage 32 is tapered, from the rectangular area visible in the top of the block, to a larger rectangular area in the base of the block (not visible in Figure 3), corresponding generally to the internal cross-section of the Uchannel starter blocks 16. The top of the block 20 includes a rebate 34 around the periphery of the internal passage 32. Projections 36, corresponding to the shape and position of the projections 28 on the starter blocks, extend from the side walls, forming a recess 38 on each side of the cover block 20.

Each flue block 22 is generally rectangular in plan view, as shown in Figure 4, and has an internal passage 40 of rectangular cross-section extending through the block, offset from the vertical axis of the flue block 22. The internal passage 40 corresponds to the upper cross-sectional area of the internal passage 32 on the cover block 20. The top of the flue block 22 includes a rebate 42, corresponding to rebate 32 on the cover block 20, around the periphery of the internal passage 40. The base of the flue block 22 has a complimentarily shaped lip (not shown) around the periphery of the internal passage 32. A second passage 44 of square section extends vertically through the flue block 22, adjacent the internal passage 40, to reduce the weight of the block. Two projections 46 extend from the right hand side of the flue block 22, as viewed in Figure 4, which form a substantially U-shaped formation or recess 48. Three projections 50 extend from the left hand side of the flue block, as viewed in Figure 4, which form two substantially U-shaped formations or recesses 52. The projections 46 are located diametrically opposite the recesses 52 and correspond in shape and cross-sectional area to the recesses 52.

The flanking blocks 24 are generally of square cross-section and each include a central rectangular passage 54 extending vertically through the block 24, as can be seen in Figure 5, to reduce the weight of the block. Three identically shaped projections 56 extend from diametrically opposed

positions on two sides of the flue block 24, which form two substantially U-shaped formation or recesses 58 on two sides of the block 24. The projections 56 and recesses 58 correspond to the projections 50 and recesses 52 on the left hand side of the flue block 22, as described above.

The flue stack blocks 16,20, 22 and 24 are purpose made, pre-cast from lightweight concrete, and the use of recesses 52,58 assists in further reducing the weight of the blocks.

Each guide 26 has two parallel limbs offset from, and connected to one another by a transverse member, as is best illustrated in Figures 6 to 9. The guides 26 are each connected to an opposing face of a respective stud 12 through one of the parallel limbs, for example by nails or screws, with the end of the limb positioned flush with the front face of the stud 12.

As can be seen in Figure 6, the starter blocks 16 are spaced apart from the studs 12 by the guides 26. The other limb of each guide 26 not connected to a stud 12, hereinafter referred to as the"free limb", is in abutment with the projections 28 adjacent the open end of the channel section 18.

Hence, the transverse member and free limb of each guide 26 enable the starter blocks 16 to be correctly positioned and aligned with one another between the studs 12, and provide lateral support to the flue stack 14.

Similarly, the cover block 20 is correctly positioned in the flue stack 14, in alignment with the starter blocks 16, since the projections 36 on either side adjacent the front ofthe cover block 20 are in abutment with the free limb on each guide 26, as can be seen in Figure 7.

At each course of flue block 22 and flanking block 24, the free limb and transverse member of each guide 26 are at least partially received in a recess in a respective flue block 22 or flanking block 24, as can be seen in Figure 8, and more clearly in Figure 9. The free limb corresponds substantially in length to the width of the recesses 52 and 58 and the transverse member corresponds substantially in length to the depth of each recess 52,58. The guides 26 are thereby partially receivable in the recesses to enable the respective blocks 22,24 to be correctly and easily positioned on the flue stack 14, and to provide lateral support to the flue stack 14. The flue blocks

22 and flanking blocks 24 can be simply aligned by abutment with only the front facing surface of the transverse member of a respective guide 26. Hence, the process of construction of the flue stack is simplified over conventional systems using a U-channel guide means.

An exit block (not illustrated) may be provided, in communication with the flue passage, on the uppermost course of the flue stack 14, as a terminal for connection to a metal exit flue pipe, for example.

To assemble the gas flue system 10, the vertical timber studs 12 are positioned at a pre-determined spacing prior to installation of the flue stack 14. The galvanised steel guides 26 are secured to the inwardly opposing faces of the studs 12, respectively, by nails or screws for example, and provide simple means for aligning and positioning each course of the flue stack 14. The guides 26 are provided in 1.2 m lengths and are fixed in place as the work progresses, starting from the base system prior to the positioning of the first course of the flue stack 14.

It is usual for the first starter block 16 to be laid directly onto a floor slab of a building, in which case a bead of bonding compound (not illustrated) is extruded directly onto the floor slab, to receive and secure the first starter block 16 in position between the guides 26, as shown in Figure 6. The second and third starter blocks 16 are positioned successively on the first starter block 16, each laid starter block 38 being provided with a bead of bonding compound to its upper surface to receive and secure the next block.

The cover block 20 is positioned, as shown in Figure 7, onto the assembled starter blocks 16 and a bead of bonding compound is extruded onto the grooved rebate 34 on the top of the block. A bead ofbonding compound is then extruded onto the lip on the lower surface of a flue block 22, to be located into the groove on the cover block 20. The flue block 22 is introduced between the guides 26, just above the cover block 20, for example 10 centimetres above the cover block 20, and positioned with the guide 26 on the right hand side of the gas flue system 10 received within the recess 52, as shown in Figure 8, before being positioned securely on the cover block 20, i. e. with its lower lip received in the rebate on the cover block 20. A flanking block 24 is then

introduced between the guides 26, at a height just above the first flue block 22. The flanking block 24 is positioned with the left hand guide 26 received in the recess adjacent the front ofthe block, as shown in Figure 9, and then lowered into position on the cover block 20, in cooperation or in substantial inter-engagement with the projections 46 and recess 48 on the flue block 22, as shown in Figure 8. Any surplus bonding compound which is forced out into the flue passage must be removed. Beading compound is then applied to the upper grooved rebate 42 on the flue block 22.

The second course of flue/flanking block 22,24 is arranged alternately on the assembled flue stack 14, i. e. with the flue block 22 on the left hand side as viewed, substantially in the manner described above.

Successive courses of flue block 22 and flanking block 24 are stacked on top of one another to the desired height, in the manner described above, ensuring that the flue passage remains devoid of bonding compound. During construction, a successive flue block 22 can be easily aligned by positioning the lip into the rebate of a previously laid block. The bonding compound is applied between each course of the flue stack 14, to provide an airtight seal between the courses.

An exit block, not illustrated, may be positioned on the uppermost flue block 22, in communication with the flue passage, at the top of the gas flue system 10, usually with a lintel and timber support provided on top of the exit block. The gas flue system 10 may then be connected to a terminal, such as a metal flue pipe or chimney pot, for example.

The guides 26 provide a simple means for aligning and positioning each course of the flue stack 14 than is used in conventional gas flue systems. Successive flue blocks 22 can be introduced between the supports substantially at the desired height for the respective course on the flue stack 14. The flanking blocks 24 can be easily aligned with the flue stack 14 by cooperation with the guide means 26 and have only to be lowered into position on the stack by a distance corresponding substantially the height of the respective course ofthe flue stack 14. The bonding compound can be applied using a mastic gun, for example, and the lightweight, purpose made blockwork can be assembled easily, without the need for a specialist tradesman, e. g. a bricklayer. Assembly of the gas flue

system according to the invention is thereby simpler and more expedient than known systems for timber frame buildings. It is an advantage of the invention that the flue blocks include recesses, such that the less material is used in manufacture of the blocks than with conventional flue blocks.

Although the invention has been described with particular reference to timber frame buildings, the gas flue system and method according to the invention is also suitable for use in steel frame buildings. In this case, the vertical supports will be steel sections, and the steel angle sections and cover plates will be secured to the supports by suitable means, e. g. bolts or rivets.

The steel guides may be supplied as preformed continuous lengths, to the required height, as opposed to I m sections, as described.

Claims

Claims 1. A gas flue system comprising a pair of laterally spaced supports, a flue stack disposed between the supports, and guide means disposed between the flue stack and the supports for aligning the flue stack, the flue stack including a plurality of superposed flue blocks defining a flue passage, in which the flue blocks are adapted to at least partially receive the guide means, and the guide means are at least partially received by the flue blocks, thereby aligning the flue stack and providing lateral support thereto.
2. A gas flue system as claimed in claim 1, in which the flue blocks are generally rectangular and include a formation for at least partially receiving the guide means the formation.
3. A gas flue system as claimed in claim 2, in which the flue blocks are generally rectangular and formation is in the form of a projection on the side of the flue block.
4. A gas flue system as claimed in claim I or 2, in which the flue blocks include a formation in the form of a recess on the side of the flue block, in which the a respective guide means is at least partially received.
5. A gas flue block as claimed in claim 4, in which the recess is substantially U-shaped.
6. A gas flue system as claimed in any preceding claim, in which the guide means include a limb which is at least partially received by a respective flue block.
7. A gas flue system as claimed in any preceding claim, in which the guide means are secured to a respective support.
8. A gas flue system as claimed in any preceding claim, in which the guide means include a limb for connecting to a respective support

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9. A gas flue system as claimed in any preceding claim, in which the guide means include a first limb which is at least partially received by a flue block at each course of the flue stack, and a second limb which is connected to a respective support.
10. A gas flue system as claimed in anypreceding claim, in which the guide means includes first and second limbs, which are parallel and off-set from one another.
11. A gas flue system as claimed in claim 9 or 10, in which the first and second limbs are off set by a third limb transverse to the first and second limbs.
12. A gas flue system as claimed in claim 1, in which each flue block includes a recess having a width w and a depth d, and the guide means include a free limb and a transverse member, the free limb corresponding substantially in length to the width w and the transverse member corresponding substantially in length to the depth d, such that the free limb is received in the recess and the transverse member is at least partially received in the recess.
13. A method of assembly for a gas flue system, the method involving the sequential steps of : a) providing a pair of laterally spaced supports at a predetermined spacing from one another; b) providing guide means on each support, and c) assembling a flue stack between the supports, the flue stack including a plurality of superposed flue blocks defining a flue passage, the flue blocks being adapted to at least partially receive a respective guide means, in which each course of flue blocks is placed into position in the flue stack with the guide means at least partially received by the flue blocks.