The normal Stock Brick these days comes in a metric size of 215 x 102 x 65mm and Arch Bricks are categorised in BS 4729 as AR.1 - Tapered Header, and AR.2 - Tapered Stretcher. There is a narrow limit of the specified sizes available from manufacturers, and most tapered bricks are cut to job by a competant brick cutting company.
From the above, it will be seen that Arch bricks can be laid as single or multiple header courses, or stretcher courses, which is more normal. Don't forget to add the width of mortar joints on multiple course Voussoirs.
To cut a tapered brick, the cutter needs to know the stock size from which the brick is to be cut, and the outside and inside widths in order to determine the taper.
In working out the number of bricks to an Arch, consideration will have to be given to the thickness of the mortar joint to be used. An ordinary mortar joint will normally be 10mm thick. However, using lime/water mix, the joint can be made as fine as 1.5mm. The trouble with this traditional mix is that the lime is soluble in water and does not adhere strongly to the bricks. In time, the jointing material may perish, and the bricks may slip out of position. To prevent this from happening, joggles are formed between the bricks, and will need to be specified, which are semi-circular grooves cut in both faces of each brick. When the Arch is formed, there are roughly circular holes between all the bricks, and into these holes is poured a wet mix of cement and sand, which hardens and prevents the bricks from slipping out of position.
If you would contact us with your Arch sizes and details, we can supply you with a scale size representation of the Arch, or full size printouts if needed, before cutting takes place. Computer programed for accuracy, details will be returned virtually by return of mail. Get in touch, - we are quite friendly, - really !
Visit us by E-Mail: firstname.lastname@example.org
We also have a factory at Wrexham - they are good too, ring 01978 760600