The following is excerpted from “Doormaking & Window-Making,” and refers to frames for exterior doors. (The book instructs that interior “doors are usually hung in “jamb linings,” instead of door frames, these being fixed in the walls after the house is built.”)
A handbook on doors would hardly be complete without some reference to door frames, and in this chapter we propose to give a short description of the various kinds of frames in general use, and to show how to set out and make them.
Fig. 102 is the elevation of an ordinary frame, consisting of two posts or jambs, sill and head: a rebate is formed in the posts and head; to correspond with the thickness of the door, and the other edge is usually chamfered or beaded in some way, as shown in Figs. 103 to 105. The standard size for the scantlings used for door frames is 4-1/2 ins. by 3 ins., although in special cases these are varied as circumstances demand. The rebate should always be made so that the widest way of the stuff takes the thrust of the door, as shown in the above-mentioned drawings. Fig. 106 shows the rebate made the opposite way, as usual in some parts of the country, but this is a very faulty style, the posts yielding every time the door is slammed.
In facing up the timber, the face (or rebate) edge, should be the outside of the tree as it was grown : this can be ascertained by the grain at the end, the correct form being as in Fig. 107, incorrect as Fig. 108. Attention to this apparently unimportant matter makes all the difference to the springing of the posts, as, if formed as in Fig. 107, the wall keeps them straight and the door will not require easing; whereas if made as Fig. 108, the posts will spring into the doorway, and the door will require frequent easing to make it work freely.
Fig. 109 shows the setting out of the posts : at the sill end the two shoulders are straight across as on the right; but at the head the shoulders at the face side must be 1/2 in. longer, to fit up into the rebate, as at A, this shoulder being made to the height of the door. The above setting out applies to the section of frame as Fig. 103, where the chamfers are made on the posts only, and the head left square, as in Fig. no, or to any other section where the ornamentation is on the posts only. If the section as Fig. 104 is used, the bead is usually taken round the head, as in Fig. 111, and then both shoulders will be of an equal length, the bead being mitred at the intersection.
This also applies to Fig. 105, where an extra length must be allowed beyond the height of the door, to allow for the bead on the edge of the rebate; both this and the large chamfer running round the head, as in Fig. 112. This latter should not be mitred at
the angles, but the posts should be scribed to fit the head, as in section Fig. 113. Should it be preferred to stop the chamfers, as Fig. 114, the first setting out will be the correct one.
The setting out of the head and sill is shown in Fig. 115. The mortise lines are not affected in any way by the section of the frame, provided that the tenons are kept to the square portion, the rebate coming to one side, as in the section (dotted lines), Figs. 103 to 105. Sufficient length must be left on the head and sill to allow them to project at least 1-1/2 ins. beyond the jambs, when the frame is together, and slot mortises should always be used. The projecting horns of the head and sill are cut as Fig. 116, A or B, according to the thickness of the wall they stand in, and also according to the position they occupy in the wall ; the bricks, being cut to fit the horns, hold the frame tightly.
Fig. 117 shows the upper end of a door jamb after the tenon is cut, section as Fig. 103. In some parts of the country the sills of outside door frames – that is , the frames which are fixed in the outer walls of house or building of any kind-are made wider than the jambs, and are bevelled, as Fig. 118, the bevel starting at the rebate line. This is a very good idea, the wet having a better chance of getting away; but in these days of cheapness it is too often considered that the extra work of bevelling the sill and cutting the shoulders to fit takes too long; it is, however, the proper thing to do.
Fantastic little book! I use it often and have read it several times. I love the preface.
While not a beginner book, it is an amazing look at building good reliable doors. I used to replace a bedroom door and repair doors in my current 1900’s home.
I have the book and like it but I have to re-read the descriptions and examine the corresponding figures several times because the orientations of the sketches are confusing. For instance why in figure 107 and 108 is the rebate filled with wood? What is that trying to show? Also the posts are oriented laying down when they should be vertical to be more clear about it. Sorry but is it just me?
I believe it’s to show the grain in the rebate. It’s shown lying down so you can see the end grain.
Yes I do agree that some details need deciphering. I think the figures are meant to show the parts as they would be seen when being worked. As for figures 107 and 108, the important information is the orientation of the growth rings to help control the direction of any bowing. The author is discussing how to orient the timber before rebating. And in practice, I have found this to work beautifully.