Vinyl flooring material 4' x 4', self adhesive
How to Assemble
Cut your full plywood board (commercial plywood is normally 48" x 96") in two (2) 12" x 48" sections (A and B) and three (3) 24" x 48" sections (C,D and E).
The first step in building the whelping box is to build a folding door that allows the mother access to and from the box. To start, take the two 12" x 48" sections (A and B) and lie them side by side so that the 48" edges are lined up. This should now be a 24" x 48" section, cut in half. Attach the top and bottom halves with 3 hinges. Place one hinge about 10" from one end and repeat on the other end. Place a final hinge in the center. You should now have a 24" x 48" board, in which the top half can be folded down. Now apply the gait hook eyes to the top section. Place one eye through the edge of the board, through the thickness of the board (not on the same surface as the hinges). The eye should stick out of the edge of the board. Repeat on the other side. Make sure that the hinges are placed so that they are on the outside of the box and allow the top half of the door to fold away from the box.
The second and third sections (24" x 48") of the plywood are going to be the sides (C and D). On each 24" edge, apply a 1" x 2" wood strip on the inside of the box with 1 1/2" wood screws. The fourth section will be the back (E).
Attach the fourth section (E) to sections (C) and (D), using 1 1/2" wood screws. The screws should go from the outside of the box into the wood strips. Two to three screws on each side should suffice, but make sure that the length of the screws is appropriate and they do not protrude through the wood strip (potentially harming the dogs).
Attach the front of the box, the already assembled door, to sections C and D with 2 screws on each side. Only attach the bottom portion of the door, as the upper portion will be the swinging door. Make sure the gait hook eyes are on the upper edge.
Apply the gait hook on the upper front corner of sides C and D. Be sure it coincides with the eyes previously placed on the front panel (door).
Now you have all four walls of the whelping box attached.
A floor can easily be added to the bottom of your whelping box by using a 48" x 48" piece of plywood. Invert your whelping box. Screw the floor (F) into the 1" x 2" wood strips on the four edges of sections C and D. If you wish to reinforce this you can apply "L" shaped corner braces to the floor/side interfaces. Two braces per side should be sufficient to secure the floor.
The floor is optional. Some breeders actually prefer no floor. In this case, set the floorless whelping box on the flooring surface of choice or some easy cleaning surface like tarp or plastic liners. Cover with newspaper and then with other bedding material like towels or blankets.
If you have any rough surfaces on the wood, sand and smooth over.
The Puppy Rail
To protect the puppies from being crushed by the mother you must place protection inside, commonly known as a puppy rail, an area for the puppies to hide under.
Take two 4" x 1" x 48" wood strips. The first one should be applied inside the box from one side to the other, about 6" from the floor. Attach with 2 screws from the outside at each end. Do the same with the second one on the opposite wall.
Take two 4" x 1" x 40" wood strips and apply a 3" x 5/8" mending brace on each end. Now attach these strips to the previously placed wood strips and screw in place.
Start introducing the female to the whelping box about a week prior to whelping. Let her spend time in the box; include her blanket and favorite toys. Two days before her estimated delivery date cover the flooring area with paper and bedding material (towels or disposable whelping box liners). The mother will rearrange the bedding to her liking.
If you don't want to build your own whelping box there are commercial plastic whelping boxes available from pet catalogs or companies such as "Dura-Whelp" (1-800-998-3331). They are available in the following sizes: 34" x 34", 40" x 40", 48" x 48" and 48" x 60".