GB2274910A - Chimneys and flues - Google Patents

Abstract

Chimneys and flues are made up of blocks each having a passage therein which, in the finished chimney or flue, define the flue passage. The blocks are automatically aligned by providing each block with a projecting rim 16 around the flue passage at one side of the block and a recessed shoulder at the other side. The rim 16 of one block fits into the shoulder of the adjacent block and a compressible preformed sealing gasket 20 is positioned round the rim 16 before the blocks are placed one on top of another. The gasket is of a thickness greater than the rim height before compression, and is compressed to a thickness less than the rim height in use, but not so much that the gasket takes the full load between the blocks. <IMAGE>

Description

Improvements Relating to Chimneys and Flues This invention relates to chimneys and flues, and for ease of description hereinafter, reference will be made only to flues, but it is to be understood that the invention also applies as will be readily understood to chimneys.

A flue for a domestic dwelling or other building or structure typically comprises a plurality of flue blocks positioned one on top of another. Each flue block is provided with a through passage, and the passages of the respective blocks when stacked one on top of another interconnect to define the through passage.

In the coupling of the blocks together to build up the flue, it is important that between adjacent flue blocks there is provided a seal to prevent for example the escape of flue gases which at best is undesirable, and at worst could be dangerous. When flue blocks are arranged one on top of another to form a flue, the installer should effect a check at various stages of the building of the flue in order to ensure the sealing of the joints between blocks, but this is not always performed and in particular in the case of domestic dwellings is frequently not carried out. There is a need therefore to ensure that an effective means of providing for sealing between the blocks is provided, and it is also preferred that such means be carried into effect as efficiently and as easily as possible by the building worker.

In the case of flue blocks for domestic dwellings and other buildings, the blocks are provided on respective faces with a tongue or rib which projects from one face, and a socket or recess on the other face to ensure the correct alignment of the blocks, and also to prevent lateral movement of respective blocks. The blocks can be stacked to form the flue either with the tongue projecting upwardly, or in the reverse manner wherein the tongue projects downwardly.

In order to seal respective blocks together, in the case where the tongue projects upwardly, it is known to inject a ribbon of sealing compound around the tongue on the outside thereof so that the sealing ribbon rests on a shoulder of the block surrounding the tongue. When the next highest block is placed on a block so provided with a sealing ribbon, the sealing ribbon is compressed and spread due to the weight of the upper block forming a seal between the respective blocks.

If the ribbon is not applied sufficiently accurately and evenly problems can arise. If any of the sealing ribbon is missing, then an effective seal will not be formed. If too much sealing compound is applied, it can ride over the tongue and into the flue passage (the tongue projecting height is only in the order of lOmm). Whilst the method of using sealing compound is widely practised, and functions reasonably well, it nevertheless does have a number of disadvantages.

When the blocks are stacked in the reverse manner, it is common to use mortar to provide the seal between the respective blocks. The use of mortar is even less satisfactory because it is difficult to gauge the use of the correct amount of mortar and consequently there is wastage and excess mortar can fall into the flue passage.

In either method, the application of fluent composition i.e.

the sealant or the mortar means extra work for the installer and builders may not always carry out this work.

The present ivnention seeks to overcome these difficulties, and in accordance with the invention in the general aspect thereof, a compressible sealing gasket is provided in order to effect the seal between respective blocks in a flue stack.

When conventional blocks having tongue and socket couplings are used, the gasket preferably is fitted around the tongue and will preferably be of a greater height than the tongue but of high compressibility to ensure a considerable degree of compression of the gasket in order to effect the seal.

This means that the gasket being flexible and compressible can in fact comply with the surface shape of the block surrounding the tongue on the one hand and surrounding the recess on the other hand.

The utilisation of the gasket presents best advantage when used in connection with the building arrangement wherein the tongue projects upwardly from the block.

The gasket preferably is of a soft silicone rubber composition of high compressibility, and it is preferably dimensioned when it is to be fitted to the tongue, so as to be slightly smaller in inner dimension than the outer dimension of the tongue so that the gasket has to be slightly stretched in order to fit over the tongue whereby it will remain gripped to the tongue as the stack is being built.

In a particular arrangement, where the tongue projects from the face of the block by say lOmm, the gasket preferably is 15mm thick and is adapted to compress down to a thickness of the order of 3mm. The tongue and socket are dimensioned so that when one block sits on top of another and compresses the gasket, the tongue will rest on the bottom shoulder of the socket so that the load will be transferred between the respective blocks and not through the gasket so that the gasket simply forms a compressed sealing arrangement. To achieve this, the socket would have to be of a depth in the order of 7mm.

In a modified form of block, where recesses are provided at opposite sides, the gasket may be carried on an intermediate sleeve which is adapted to project into the respective recesses. In yet another arrangement, one block may be provided on opposite sides with recesses around the flue passage, whilst the next adjacent block may be provided with tongues on opposite sides and surrounding the flue passage.

Two gaskets would be placed upon the two-tongue block and the method would proceed as indicated above.

Instead of a soft silicone rubber, other materials may be used for the gasket. For example it could be of a flexible foam material.

By the simple means of the invention, the formation of the seal between respective flue blocks can be performed quickly and easily by an installer, and the installer is unlikely to omit to position a gasket between each pair of adjacent flue blocks in the building of a flue, because the bringing together of blocks where no gasket is present will make a different sound to that which will be heard when a gasket is present.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, wherein Fig. 1 shows in perspective elevation a conventional flue block; Figs. 2, 3 and 4 respectively show a perspective view, plan view and side view of a gasket for use with the block of Fig.

1 and in accordance with the present invention; Fig. 5 shows how a pair of blocks are positioned prior to being brought together to form a portion of the flue; and Fig. 6 shows the two blocks of Fig. 5 when in assembled condition.

Referring to the drawings, and firstly to Fig. 1, a flue block 10 is made of concrete or the like material, and is seen to be a generally rectangular block provided with a through passage 12 for flue gases.

The passage 12 is offset longitudinally in relation to the block so that the block has a nib 14 for a purpose to be described hereinafter.

The passage 12 extends from the bottom surface to the top surface of the block 10, and where it emerges through the top surface it is surrounded by a raised tongue 16 whose sides slope slightly as shown. The tongue 16 may be of a height in the order of loam.

In the base of the block, there is a socket or groove 18 sorrounding the passage 12, the socket or groove 18 being of complimentary shape to the tongue 16 so that the blocks can be stacked one on top of another with the tongue 16 of each lower block engaged in the socket 18 of the upper block.

The tongue and socket connections provide for alignment of the blocks and for the prevention of lateral movement of the blocks one in relation to another. It will be appreciated that the passages 12 of the respective blocks combine to form the final flue passage. In order to provide an effective seal between the adjacent stacked blocks, which is required to prevent leakage of flue gases, a gasket of the configuration shown in Figs 2, 3 and 4 is provided, such gasket being indicated by reference numeral 20. The gasket 20 is of rectangular configuration so as to fit around the tongue 16 as shown for example in Fig. 5. Fig. 5 also shows that a pair of adjacent blocks 10A (lower block) and lOB (upper block) are arranged opposite handed so that the nibs 14 lie to opposite sides of the flue passage 22.This is to ensure that the flue blocks can be built brick fashion with the building blocks of the remainder of the structure.

As shown in Fig. 5, the gasket 20 projects above the top of the tongue 16 which it surrounds due to the fact that the gasket is in the order of a height of 15mm.

Fig. 6 shows the arrangement wherein the upper block 10B has been lowered onto the lower block 10A. The gasket 20 has been compressed in order to form an effective seal between the blocks, and it has been compressed to such an extent that the tongue 16 of the lower block rests on the shoulder of the recess 18 of the upper block so that the load between the respective blocks is transmitted directly from one block to the other and not through the gasket 20 which is simply compressed in order to form a seal between the blocks.

As the flue is built up so gaskets 20 are used between respective blocks.

An extremely efficient and effective method of providing a seal between the respective blocks results, avoiding the use of a fluent sealing material whether a sealing composition or mortar.

Claims (10)

1. A flue stack comprising flue blocks and pre-formed compressible, flue passage, sealing gaskets between adjacent blocks.

2. A flue stack according to claim 1, wherein said blocks have tongue and socket couplings and the gaskets are fitted around the tongues of said couplings.

3. A flue stack according to claim 2, wherein said gaskets are compressed to an extent to form a seal but not to carry the full load acting between adjacent blocks.

4. A flue stack according to any claim 2 or 3 wherein the gasket in its uncompressed state as of a thickness greater than the height of the tongue.

5. A flue stack according to claim 1, wherein the blocks have recesses on opposite faces and the gaskets are carried on intermediate sleeves which are adapted to project into the said recesses.

6. A flue stack substantially as hereinbefore described with reference to any of the embodiments herein described.

7. A sealing gasket for use in a flue stack according to any one of the preceding claims.

8. A method of erecting a flue stack comprising placing flue blocks one on top of another, and positioning compressible pre-formed sealing gaskets around projecting members which project into recesses in adjacent blocks to align and prevent relative lateral movement between blocks so that the gaskets are compressed due to the weight of upper blocks so that said gaskets form seals around the flue passage and between adjacent blocks.

9. A method according to claim 8, wherein the gaskets are compressed only to such an extent as not to bear the full load acting between adjacent blocks.

10. A method of erecting a flue stack, substantially as hereinbefore described with reference to the accompanying drawings.