This section is from the book "A Practical Treatise On The Joints Made And Used By Builders", by Wyvill J. Christy. Also available from Amazon: Practical treatise on the joints made and used by builders.
Recessed Joint is one raked back, or grooved for effect. One variety has been described under Keyed Joint. Though often admired for the play of light and shade which it affords, it is on the whole objectionable, owing to its offering in the aggregate a large surface for the lodgment of rain.
Rough Joint occurs when the joints are left unstruck, and protruding to afford a key for the rendering.
This is formed between bricks brought down by rubbing on the rubbing stone to any required bevel. Bricks have frequently to be cut before they are rubbed.
Saddle Joint occurs between a saddle piece and the overlying brickwork, and is similar to the corresponding joint described under the mason.
Slip Joint is formed when a chase is cut in old work for piecing new work to it, in order that a straight joint may not show, and that the new work may settle without hanging upon or straining the old.
Spring Joint is a loose joint.
A long joint proceeding in the same line or plane without a break. When running in a slanting or vertical direction it is a source of weakness, and almost any artifice is allowable to curtail or avoid it if there be no orthodox way of escaping it.
Struck Joint is formed by drawing and pressing the point and edge of the trowel along the mortar joint until it is quite smooth, and forming a slightly sloping surface by keeping the trowel well in towards the top edge of the joint. The bricks ought to be laid perfectly level on bed, and in a true plane as to face, with the mortar left as full on the face as possible to allow for pressing in. As soon as the course is laid out all holes in the joint must be stopped, and then it is ready for striking, which is done by smoothing the mortar as above described. Very often the trowel is run along the bottom edge instead of the top, but whichever plan is adopted the joint ought to be as full as possible without projecting. When it slopes outwards and downwards by striking the joint according to the first method, there is little chance of any wet lodging; and if the remaining or most projecting edge, in either case, is cut off straight with the trowel, either with or without a rule, the joint is sometimes said to be struck and cut, though the term "struck" includes cutting.
Sunk Joint is the same as a recessed joint, or one drawn with a thick jointer.
Terra Cotta Joint is one peculiar to this material when moulded in alternate thin and thick blocks for facing, which are usually about 1½ in. and 6 in. thick respectively. Both sizes have corresponding but reversed lips, by which means the thicker blocks hold the others in place as in Fig. 11. The plain butt, however, is as often as not used, and blocks for columns, and other features have joggled or dowelled or grooved and tongued joints.