If you are considering building raised beds for faster soil warming, drainage and germination, You can place your cold frame on top of the raised beds to help acheive the results quicker. Here are some basic plans to help with the task.
RGH 4322 Start with a top frame that the outside dimensions are 22½" x 43½".
This can be made from most any 1½"wide stock. Cedar, Redwood, Locust, plastic composite or any decay resistant wood is good. Plywood will delaminate and not last as long as other solid woods especially if not stained or painted. Pressure treated may have harmful toxins in it and should be avoided for vegetable gardening.
After the frame is built add a ¾"x2¾" flange to the upper portion of the top frame. Lap half of the flange on the raised bed and half above to capture the cold frame base. This can be made out of
1"x6" fence board material.
Fasten this to the top frame by nailing the flange half on the top frame and half above it. The cold frame will sit nicely down in the area. Duplex 8p nails drilled into the four corners hold the cold frame snugly.
Next you can build the actual raised bed. Make this the outside diminsion of the top frame roughly 45"x24". Fasten it together with screws.
Most raised beds are 6" to 24" tall.
Place some hinges on the backside of the frame attaching it to the top frame.
We added a prop up stick that can be removed easily. Just drill a hole in it and slip it on the 8d duplex nail holding the cold frame to the top frame.
Being able to lift up the cold frame and prop it open really makes tending to the plants alot easier.
The auto vent opener lets the cold frame be worry free so in case if you forget to vent in the morning and close at night you will not fry or freeze your precious plants.