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.
Half Lap Joint is another name for the common variety of halved joint.
Halved Joint is produced by halving or notching half through, and is used for connecting timbers that cross each other, and that either pass or not. Its characteristic is that a piece is cut out of each timber and down to half the thickness, and that when the upper timber is fitted down upon the lower, the top and bottom surfaces of both are flush. In only common or square halving, shown in Figs. 37 and 38, is an equal and corresponding piece taken out of each. The other varieties are known as bevelled halving, Fig. 39; dovetailed halving, Fig. 40; and dovetailed and housed halving, Fig. 41. In common halving, if the ends do not pass, they must be spiked or nailed to prevent a draw.
If anything more than simple bolting is required, this or rebating and bolting is the best kind of joint for heavy timber work exposed to sea action, as it admits of tightening up, whereas the working loose of the tenon in a mortise joint cannot be remedied.
Heading Joint is one between the butting ends of two beams or timbers, and may be either a scarf or a simple butt, etc. In many curved ribs the heading joints of the logs interlace or are crossed so as to bond well throughout the layers. The same term has been given to the joint at the extremities of rafters when each pair is made to unite either by simple lapping, or with an angular half mortise and tenon angle joint, which sometimes occurs between principal rafters when framed together without king-post or ridge-piece.
Housed Joint is similar to that of the mason, and consists in letting in the ends of timbers of any section or scantling into walls, cast or wrought iron boxes, heads, sockets, shoes, etc. Fig. 42 shows a mode of housing principal rafters into the head of a king-post whereby their heads butt against each other, in which position they are more likely to keep the king-post up than when the ends press against and compress its vertical fibres.
Housed and Dovetailed Joint is a variety of halving, or of notching when the pieces joined are not cut or sunk to the same depth. It is illustrated in Fig. 41, and is considered a stronger joint than that made by dovetailing only. The lip joint, Fig. 46, is another variety.
This is an alternative term for oblique joint, under which name it is noticed.
Indented Joint is identical with a tabled or a tabled and indented joint.