Those grooves are machined on the back of most larger trim(base-casing and jambs.) they are there to make the trims stay flat and add a little flexibility. You do not need to add them to your custom jambs.
Why does casing have a groove on the back?
A backout is plow or relief cut on the backside of a wooden moulding to help with cupping and or warping; it also allows for airflow between objects and provides a good transition between framing and sheet rock.
What is the difference between a door frame and a door jamb?
Us mere mortals will refer to the entire unit as a door frame, when in actual fact, there are many elements to a door frame, such as the jamb. A jamb is the flat surface that runs vertically up either side of the door frame. The door jamb is vital to the running of the door. … The door frame is all the elements combined.
What are the grooves in a door called?
Dado Joint. Also referred to as a housed joint, it is a rectangular groove across the grain of a wood member into which the end of the joining member is inserted.
What does a relief cut mean?
A preliminary cut with a jig saw or band saw to prevent the saw from binding, when cutting a curve in a piece of wood.
Is a door jamb necessary?
Locking and Protection. A strong door jamb provides a desirable sense of protection against burglary and theft. While one may believe the type of door or the quality of the locking system to be most essential, without a strong jamb, neither will matter.
What kind of wood is used for door jambs?
Most jambs are made from 3/4-inch-thick pine, hemlock or fir. These softwoods are economical and easy to work with. You can also use oak or any other hardwood for a stain-grade jamb, but hardwoods are pricey and harder to work with, especially when preparing the jamb for hinges.