Figure 2. Lap joints.
illustrated in figure 2, B. If one end of a lap joint joins the
other in the center, as shown in figure 2, C, the joint is
known as a middle lap joint.
2-11. Lap joints are used by the carpenter in framing
timbers for sills and girders. Cabinetmakers use lap joints
Figure 4. Grooved joints.
for connecting crossrails to the side of cabinets and for
many other types of frames.
plain dado in regard to the horizontal member, which is
2-12. Grooved joints. Grooved joints are those which
rabbeted to fit the dado. To counteract strain, a dado joint
have a groove, or recess, cut into one member, either with
can be dovetailed, as shown in figure 3, D. Dovetailed
the grain or across the grain, into which the edge or end of
dado joints can be constructed in the blind, or stopped,
the other member is fitted. The grooved joint is a familiar
joint to the cabinetmaker and has many variations.
2-14. Grooved joints have the groove, or plow as it is
2-13. Dado joints are actually grooved joints with the
sometimes called, running with the grain of the wood.
groove running across the grain of the wood. They are
They are used extensively in panel construction. Figure 4
used extensively in cabinetwork drawer construction. The
illustrates three methods in which a member can be
dado is a housing, or groove, cut into one member with
inserted and fitted into a groove. Grooved joints can be
the other member fitting into this groove. A plain dado is
plain or cut with a rabbet or tongue and can be joined with
one which extends completely across the board. (See
either glue or nails. However, when a panel is inserted
fig. 3, A.) When the groove, or dado, is not extended
and surrounded by a frame, the panel is made to fit snug
completely across, as illustrated in figure 3, B, it is known
but is not glued or nailed. This allows the panel to swell
as a stopped, or blind, dado. A shouldered dado (see
or shrink without breaking the frame. Grooved joints can
fig. 3, C) differs from the
be cut with the circular saw, using a dado head.
2-15. Miter joints. Miter joints are diagonal joints
used extensively for frames and moldings. Shown in
figure 5, A, is a plain miter joint, which can be fastened
with glue, dowels, wood screws, nails, or corrugated
2-16. The mitered half lap joint (see fig. 5, B) is similar
to the end lap joint and can be mitered to any desired angle.
This type of joint can be fastened with, glue, nails, wood
screws, or a combination of glue and metal fasteners. The
splined miter is a method used to reinforce
Figure 3. Dado joints.
Figure 5. Miter joints.