Strap hinges are generally used for supporting heavy, swinging loads such as barn doors and thick board-covered shed doors. The strap hinge is generally constructed of galvanised steel with a large-diameter hinge pin. The long wings or straps of the hinge are usually in the shape of long, rounded triangles to distribute the weight evenly over a larger surface area. By following basic procedure, you can install the strap hinge in a few minutes.
Lay the door on the ground or any suitable flat surface. The more comfortable the height, the easier on your back for bending over.
Lay out the strap hinges on the door, using the tape measure. Generally speaking, the strap hinges should be approximately 30 cm (1 foot) from either end of the door. In other words, you want one strap hinge 30 cm (1 foot) from the top and the other 30 cm (1 foot) from the bottom of the door. For very heavy doors, you may want to place a hinge in the centre distance between the two outer hinges. You should centre the hinge horizontally with the centre of the hinge pin on the edge of the door.
Drive the lag screws or other types of fasteners into the door with the driver. This could be an electric drill with an appropriate driver bit such as a socket head for lag screws, or a Phillips head for Phillips head screws.
Place the scrap wood on the floor of the door opening and then set the door into the door frame. The scrap wood will aid in centring the height of the door in the opening. Use the tape measure to check that there's an even reveal all around the door in the door frame.
Secure the strap hinges to the door frame with the fasteners as in Step 3. Be sure that all hinge holes are filled with the fasteners before removing the scrap wood supports. Test the door for a proper swing back and forth in the door frame.
Don't use nails for securing any type of hinge to doors and door frames. The nails can easily be pulled out, and the door may fall from the opening.