I wanted an inexpensive truck topper for my 1960 F100. It is a full size truck and a bit rough around the edges so I didn’t need anything shiny and fancy. I want to be able to keep cargo dry as we enter the Pacific Northwest rainy season and open up the option to sleep in the back from time to time. I wanted it to be light enough that it was easy to load / install by myself.
3 sheets 1/8” maple plywood (door skin veneers) approx $25 each
2 sheets 1/2” plywood approx $30 each
40’ fibreglass tape and resin. Approx $100
1 gallon bedliner approx $100
4 c clamps
Step 1: Cut the Ends
I used 1/2” exterior grade plywood for the ends. Measure the width of your truck and then determine the height you want your canopy to be. I wanted to have 1 piece sides and roof so I cut a radius into the roof corners that will have plywood bent around to transition the wall to roof.
I cut one end then set it on the truck to see if it was what I wanted.
I cut both ends the same. Don’t cut the door out yet.
Step 2: Add Bottom Rails.
I cut 2 strips of wood (I used some old cedar) 1 1/2 x 1” thick by 8’ long. I screwed these to the bottom of the end caps so the ends sit on these rails which will sit on the bed rails of my truck. This effectively lifts the height of the topper by 1”. Next time I would make them wider, as wide as the truck bed rails you are mounting home to, closer to 2.5”.
I attached these these with screws and glue, I pre drilled all screw holes to eliminate splitting.
Step 3: Attach Sides to the Bottom Rails
Using screws and glue I attached 1/8” plywood to the bottom rails and then using screws and every 4” slowly bent the plywood over the radiused corners of the end caps. In my case the 4’ wide sheet of plywood covered the sides and came within 6” of the centre mark on my end pieces.
Once one side was complete I put it onto the truck for a test fit. It’s strong enough but still delicate... be careful or use 2 people.
Repeat on the other side with the other piece of plywood. When you are done you will likely have a gap in the middle of the roof, in my case this was 12” exactly.
Step 4: Add Roof Rails and Centre Section.
I cut 2 more pieces of cedar 7’ 11” long, 1.5” wide and 1” thick. These were screwed to the end caps centered on the line created by the two pieces of plywood. These rails support the 8’ sheet between the 2 end caps and provide a lip for the centre section to rest on.
Once these rails are in place glue and screw the side walls to them, I have lots of clamps and found this was a good place to use them. A helper would have been handy as well.
Now cut a centre section, in my case 8’ long x 12” 1/8” plywood. Glue and screw it to the roof rails and end caps.
You now have a completed shell.
Step 5: Strengthen and Seal the Seams With Fiberglass Tape.
Allow a day for the glue to cure and dry then remove the screws.
Apologies but I neglected to take pics of this part. Google fibreglass epoxy and you can see how it’s done. If it’s your first time with fibreglass just jump in. It’s amazing stuff. Get some disposable gloves.
Mix some epoxy resin with saw dust to create a peanut butter like paste and fill the screw holes.
I used 40’ of fibreglass tape (I had 6” on hand but thinner 3” would have been fine.
Cut 8’ 4” strips of tape for the bottom rails and top seams. Lay a strip of each over the roof seams. I used approx 20” of tape to spot tape the radiused corners where the plywood attaches to the end caps. This will strengthen and help seal the corners. If there are any gaps between the plywood and your end caps fill those with expoxy / saw dust before fibreglass taping the ends.
After a day or so when the tape is fully cured you can flip the topper upside down and add tape / epoxy to the bottom rails. I did this at the same time as the rest and it was troublesome as the wetted our fibreglass tape kept falling down. Ultimately I stapled it in place to get it done but it could have been neater if done in 2 stages.
Now you have a strong lightweight shell.
Step 6: Cut the Door.
Figure out where you want the door, mark lines and prepare to cut it out.
I used a circular saw but a jig saw or hand saw can work if you are making straight cuts.
First I cut the top hinge line. Once the line was cut I installed stainless steel hinges over the saw kerf.
Then I made my side cuts but didn’t cut all the way through. Stop approx 2” from the bottom and install your latches. In my case these are stainless barrel bolts. Once the hardware is installed complete the door cut. This makes it easy to install the hardware and know it’s all perdfectly aligned.
Step 7: Bed Liner
I wanted a black topper so I didn’t worry about being overly neat with the fiberglassing. If you wanted a wood look you could add a lightweight cloth to the entire topper and epoxy it then finish with a UV resistant finish. I finished the topper with bedliner from Canadian Tire. A gallon was $99 and was sufficient for the entire shell.
I added a foam gasket to the undersides of the side and front rails to keep rain out. I’ll need to find a rubber strip to add to the bottom of the door, this isn’t complete yet.
Super happy with the results. It was a weekend project and the end result is strong and light. I can load and unload it on my own. The interior is dry and cozy. The 1/8 material is strong enough for this and at highway speeds (60mph max for my old truck) there is no wobble. If you wanted to add roof racks you would need to reinforce the roof with a 2x4 frame.