Cold Frame pattern for 4 foot by 4 foot piece of plywood
Cold Frame Vent Stick
In Cold Frame Plans - Part 2, you will find a list of materials to build the style of cold frame that I like to use. And in this post, you will also find the directions for constructing a cold frame.
Part 1 - which was posted first (or under this posting),, discusses the advantages of, and some methods for, using cold frames.
Materials for two 4 foot by 4 foot cold frames:
1 - 4 foot by 8 foot sheet of 1/2 inch plywood - exterior grade
(You can have the straight cuts made at the lumber yard, but will need some way to make the two diagonal cuts to finish this portion of the project)
4 - 1 by 3 inch 8 foot pine boards
4 - 1 by 2 inch 8 foot pine boards or a bundle of lath strips to secure covers
2 - 3 foot pieces of 18 gauge perforated angle steel
1 - 2 inch by 2 inch lumber made into a ventilation stick. Cut notches in a 2 foot piece and use the stick to prop the cold frame lid open to allow for ventilation.
8 - 4 inch metal L-brackets
4 or 6 - 3 1/2 inch hinges
50 - 1/4 inch 1 inch hex bolts, nuts and washers
2 simple handles help when moving the frame
Supply of wood or drywall screws for task (3/4 inch)
Assorted tools used to complete task - hacksaw, drill, some sort of saw for lumber, screwdriver, wrench, and hammer.
Cut your plywood to the desired dimensions from the pattern above. Cut the angle steel into four 7 1/2 inch pieces. Join the box with angle steel on the inside of the front and back panels with the bolts and nuts. Use the washers on the outside. Bolt the four sides together. The finished box dimensions will be 48 inches by 49 inches and the lid you make should be constructed with these measurements in mind. Before making the lid, flip the finished box so that the lid will fit flat on the cold frame. The procedure will cause the box to be at a slant when sitting on the ground and allow more light to penetrate at this angle.
Cut 2 each lid frame boards (1 inch by 3 inch stock) 46 1/2 inches and 47 1/2 inches. Arrange these pieces for a finished square of 49 inches by 50 inches. Attach the board with the L-brackets to the inside. Attach the hinges with one side on the lid and one side on the outside back of the cold frame box. Cut some scrap plywood or paneling into 8 inch squares and then cut them in half to make triangles to attach at the corners of the lid for strength when using plastic to cover the lid frame. I hope the pictures included help in your construction.
Once the lid is made, a variety of materials can be used to cover the cold frame. Plastics that are treated against UV rays will last longer than conventional plastic. Fiberglas is another useful covering but such materials will require additional stock purchases for securing this material to the lid. Even spun polyester row cover material can be used to cover the cold frame lid. Remember to think of the weather and the crops that will be in the cold frame as the determining factor in your choice of cover materials. Lighter materials will need a central support for winter use. One or two supports attached inside the lid will help these lighter materials in a winter environment when snow covers the cold frame lids.
I have never been without these vital garden tools and hope you too can add them to your garden this season.