 |  | Carpentry for Vocational Schools - A Teacher's handbook (GTZ, 252 p.) | ||
 |  | 20. DOORS | ||
|  | (introduction...) | ||
| | 20.1. Door frame | ||
| | 20.2. Calculating of opening | ||
| | 20.3. Fixing door jambs | ||
| | 20.4. Hanging a door | ||
| | 20.5. Types of doors | ||
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TOPIC: 20. DOORS
INTRODUCTION: This topic teaches students how a door frame is made; how the opening for a door is calculated; how the door jambs are fixed into the wall frame; how a door is correctly hung; the mounting of locks and different door types.
OBJECTIVES:
20.1. Students must know the names of the parts of a door frame and how they are joined.
20.2. Students should be able to calculate the opening for a door frame in the wall frame.
20.3. Students should know the procedure for fixing door jambs in a wall frame.
20.4. Students must be able to fit hinges, door stops and locks correctly.
20.5. Students should be able to distinguish between different types of doors and define their characteristics and uses.
METHOD: This topic is taught first in the classroom and it might be difficult to demonstrate it on a real door except if a building project is going on where doors have to be hung anyway.
Prepare photocopies from the drawings on this topic to glue in the trade theory book after the topic is taught and copy the text from the blackboard.
When time is available some exercise can be made on fitting hinges and locks to a small piece of wood which is the same thickness as a door.
NOTE: At the end of this topic a worksheet is prepared for students to complete for their nightstudies.
The worksheets are corrected and assessed later.
There are a lot of different door types. External doors have to be much stronger than internal doors. Usually external doors are timber framed doors and for internal doors are the hollow core flush door type. Doors are hung to the doorframe by hinges.
The timber thickness for the doorframe is between 20 mm to 25 mm. The width of the frame depends on the wall width. The jambs are joined to the head by housing joints and nails. Before nailing the frame together, putty the timber and sand it.
Figure
To calculate the width of the door opening , measure the width of the door, add two jambs thickness and 4 mm. To calculate the height of the opening, measure the height of the door, add head and 4 mm.
E.g. Width:
|
Doorwidth |
820 nun |
|
Thickness of 2 jambs |
+ 50 nun |
| |
+ 4 mm |
| |
________ |
|
Width of opening in the wall |
= 874 mm |
Height:
|
Doorheight |
2040 mm |
|
Thickness of one head |
+ 25 mm |
| |
+ 4 mm |
| |
_________ |
|
Height of opening in the wall |
= 2069 mm |
Door opening in the wall = 874 x 2069
Figure
Measure the height of the opening and cut the door jambs at that measurement. When the door jambs fit into the opening check the level of the head. Is the head not level cut the longer jamb shorter until the head is level. Afterwards test with a spirit level and a straight edge whether the jambs are straight and level. If there is clearance between the stud and the jamb, pack timber between. The jambs are packed until they are straight and plumb on the face and the edge side. Finally, check if the edge side is in line with the wall cladding and start nailing.
Figure
Hold door against jamb. The door may not be at the right height and width. Make marks at the top and at the side. When marking the door, mark it with a clearance between jamb and door. This clearance is usually 1 to 2 mm. Plane down the edges of the door until it reaches the pencil line and put the door into the jamb for testing. If the door still does not fit, mark it again and plane it.
Figure
a) Hinging: - Put the door in the jamb and press it with the aid of a chisel into position. Take a hinge and mark across on both door and jamb. Remove the door and house the butt hinges at the door and jamb. Screw the hinges at the door. Hold door at right angles, and wedge it with chisel under outer edge, push top hinge into place and enter one screw. Remove wedge, put one screw in the bottom hinge, close and test for clearance. If it fits drive the other screws home.
Figure
b) Fixing stops: - These should be finished with a smoothing plane and glass paper. Fit the top piece in first and find position with door closed, allowing for thickness of paint. Cut upright stops in tightly, tack in position and try. If the stop against hinge edge is too close, it will cause the door to bind.
Figure
c) Door handles and latchsets:
- Latchsets and snibsets are normally fitted to internal doors and locksets to external or security doors. The first step for installing a latchset is to slide wedges under the door to keep it firm to work on. Square a line at latch height on edge of door to handle position. Mark position for holes for cylinder or tubular latch and mark the hole for locking mechanism plus a little room for play. If mortise locks are being used, drill a series of holes to the depth and height of the mortice mechanism and chisel the remaining wood away. Again allow a little room for play.
Figure
- To rebate the edge of the door to accept face of latch, install latch in hole and mark the outer edges of the flanges on the door. Using a chisel, rebate to the depth of the flange thickness, ensuring a flush fit. Install latch and handle mechanism. Adjustments may be required to enable latch bolt to move freely. Often a binding latch is the result of too tight a fit.
Figure
- Install striker plate on jamb by first closing the door and marking the position of the latch in the jamb. Rebate the housing for the striker plate. Also drill and chisel the hole to receive the latch bolt and attach striker plate. Door stops can now be fitted.
Figure
a) Solid core flush door: - This type of door is normally used as an external door where added strength is needed.
Figure
b) Hollow core flush door: - The hollow core door is light in weight and is used both as an internal and external door. Waterproof plywood and glue is used on external doors. An indication of lock side is necessary on hollow core doors. These type of doors are mass produced in standard sizes.
The standard thickness is 35 - 40 mm.
The standard height is 2040 mm. The standard widths are 610 mm, 760 mm and 820 mm.
Figure
c) Braced and ledged door: - This door is mainly used in sheds and out houses. The sheeting is normally made of flooring boards with the face edges chamfered. The boards are nailed or screwed to the ledges after which the braces are fitted and fixed. The braces always go from hinge side up.
Figure
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