Joggle Joint

"When a mortised piece is shouldered or expanded to receive the shoulders of the tenon, or when the cheeks of the mortise have jogs or notches to increase the abutting surface, such piece is said to be joggled, and the joint into which it enters is denominated a joggle joint. This kind of joint is extensively used in carpentry for connecting the heads of diagonal or inclined pieces of framing with upright or horizontal ones, as shown in Figs. 43 and 44, and is used with or without iron fastenings. Another form of joggle joint is that produced between a short or stub tenon and its corresponding mortise, a dumpy tenon being sometimes known as a joggle. Some further remarks applicable under this heading will be found in the descriptions given of oblique and tabled joints. It is as well to observe, however, that a mortise is not essential to a joggle joint. Shouldering and notching appear also to be little else than varieties of joggling, for a shoulder may be formed by increasing or reducing the width or thickness of a piece, as instanced by the queen-posts of many trusses.

Joggle Joint 42

Fig. 41.

Joggle Joint 43

Fig. 42.

Joggle Joint 44

Fig. 43.

Key Joint

This is made when slightly tapering wedges of hard wood called keys are employed to push home the different parts of joints and hold them up in their assigned places, in order to prevent too much strain falling upon the fastenings.

Keyed Joint

Keyed Joint is synonymous with one of the varieties of caulked joint, and has been already explained. It is likewise an alternative term for key joint.

Lap Or Lapped Joint

This is the simplest mode of lengthening timbers, and is made by laying one end over another and bolting through or strapping round with bent straps, having screw ends which pass through a bearing plate, or head or check plate to afford an unyielding surface for the nuts to screw up against. Fig. 45 shows the joint secured with hoops driven on whilst hot. Halving, however, is called lapping by some carpenters, and much that has been said under Halved Joint will here apply.

Lap Or Lapped Joint 45

Fig. 44.

Lap Or Lapped Joint 46

Fig. 45.

Lateral Joint

Lateral Joint is a longitudinal joint, and usually square edged, occurring between rows of planks in cofferdams, planking and strutting, etc. It also is found between the beams composing the ribs of timber bridges, and between the cushion and principal rafters of roofs of wide span. The carpenter uses boarding either rough or wrought on one or both sides, and joined lapping, or with edges square and shot only, or else ploughed and tongued, or rebated, or springed or sprung, otherwise bevelled. The latter is the best plan of jointing boarding for slating, for which and other similar work it is impolitic to use the best clean deal.