from The Century Dictionary and Cyclopedia
- Lapped about one half as much as when brought to the proper position: used of rivet-holes that do not meet properly, but are half-blind.
Sorry, no etymologies found.
This drawing shows a half-lapped dovetail as the collar tie to rafter connection.
If the rafter is framed to a post or plate that is not securely connected, the half-lapped dovetail would be better, because its interlocking geometry gives intrinsic resistance to rafter spreading.
The strips are about 2 "wide and 1/2" thick with their ends half-lapped.
Fig. 47 shows a combination of a bevelled dovetail half-lapped joint.
The two rails, which are at right angles to each other, are half-lapped and mortised; the tenon on the post runs entirely through them.
The centre portion is an example of three pieces half-lapped or, as it is sometimes called, one-third lapped.