Thru-window Long Board Support for Pick-up Trucks




About: Engineer. Advanced woodworker. Maker. Car repair. Advanced home improvement. I work from home, stuck behind a computer, dreaming of retiring from my computer job to do more fun things.

Support boards up to 16 ft long in an extended cab pickup truck. If you have a rear window that opens in the back of your truck, you can carry long material, but you need to make a support so you do not damage your window or the window trim and track.


Step 1: Take Some Measurements


  1. Width of your open window.
  2. Thickness of the top of the truck bed under the window (the part to be straddled)
  3. How high up you want to support the wood: consider window, seats, and dash board.
  4. Make the vertical rails narrower than your actual window opening. This prevents the boards from hitting your glass.

Step 2: Draw Up Some Plans and Gather Material

I made this from pretty humble looking total cost was nearly zero.

  1. 2" x 4" main support
  2. ~1/2" thick plywood base
  3. ~1/2" x 1-1/2" sticks for the vertical sides and straddle sides.
  4. Some non-slip rubber mat.
  5. Drywall screws, glue and wood filler.

Step 3: Rough Cut and Dry Assemble the Parts

  1. Cut the parts to build the basic form, and test assemble to check the fit out.
  2. Make sure it will fit and has the necessary clearances for your truck.
  3. Refine the parts. Add curved edges.
  4. Optionally, cut an arch into the 2" x 4" to reduce weight and serve as a handle.
  5. Use 1/4" round-over on the handle and the support surface.

Step 4: Put It Together

  1. Screw, nail and glue the parts together.
  2. Fill the screw countersinks and nails. Overkill? Yes, along with painting it. I had a new truck, so I figured I might as well make it look nice.

I probably should have made this just a bit narrower to protect the glass. But at the same time, I wanted the widest usable space.

Step 5: Paint and Add Rubber Pad

  1. Use spray paint or an exterior grade paint to make it look slick and protect it. Do NOT paint the surface that will support your materials: The paint will just rub off and mar your materials when you slide them in and out.
  2. Glue the rubber non-skid pad on with construction adhesive or another suitable adhesive.

Step 6: Load Material

  1. Put towels on your dash board for padding. Especially pad your windshield: Even a small amount of force can crack your window from the inside due to the curve. Think eggshell: Easy to get out of, very strong on the outside.
  2. 16' boards hang off the back less than 3 feet!
  3. Bundle the boards together with stretch wrap or bungee cords.
  4. Secure the load with ratchet straps wrapped around the bundle, at the front and back of your truck bed. You don't want the boards to swing into you while driving. (Straps and padding not shown.)



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    7 Discussions


    3 years ago

    As a professional Carpenter/Cabinetmaker/Wardrobe Installer/Maintenance Carpenter and Welder, I would like to offer a few words of advice with regard to this Instructable and also about carrying long items.

    1. Great idea, I would possibly make the side arms taller for when you want to bring home a bundle of framing timber, architraves, whatever.

    2. Create some fixing method for the bracket so that it can then be used as your strap down point.

    3. Make a similar sized unit for your rear tailgate to properly contain your load and protect your tailgate.

    4. Strap the bugger down real tight both ends so it wont move. Like robygc, I too have broken auto glass [the windscreen no less] as a load shifted under braking and crack there went the windscreen. You can easily guess the colour of my language at that point. Small cheap G clamps can add extra security, but keep them within the vehicle to avoid problems with law enforcement types.

    5. DO NOT USE BUNGEE CORDS. I had a close workmate who was seriously injured in one eye while trying to strap down a load on his car using a bungee cord, the hook gave way and came flying into his eye. The surgeon said he sees a lot of those injuries caused by bungee cords and that my friend was lucky not to loose his eye. I saw his bruised eye and it was not a pretty sight. Good ratchet straps are a wise investment. Check out professional tool shops as they often have the heavy duty ones like those used by truckies for about the same price as half decent ones at other stores.

    6. Any load projecting over your bumper should be flagged. Go to your local traffic authority website and print of a copy of the rules to keep in the vehicle. Yeah, I know the rules say once it reaches a certain point it must have a flag, but I work on the premise that if I do the right thing all the time then no one has a come back on me.

    A Hi-viz top or singlet makes a great flag and they are cheap to buy.

    I hope this helps fellow members to keep making things while avoiding trouble.

    1 reply

    Reply 3 years ago

    Great tips for a more heavy duty system. I should have mentioned, the system I made is used primarily for a few pieces of light-weight trim molding (I am just a home owner), a couple times a year. It should certainly be up-sized for real lumber. Although with larger boards, I would worry about the increased chance of damaging the dash or windshield in an unexpected traffic situation. Rack systems may be more appropriate for regular or heavy duty use.


    3 years ago

    Yeah, Supporting the long boards with something other than the GLASS didn't even cross my mind until I broke the bottom section of the window - this was one of those 'marvel at your own stupidity' moments. Good solution!


    3 years ago

    simple yet effective! Thanks for sharing

    Two Paddles Design

    3 years ago

    this looks great, much better than messing up my truck which is what I have been doing.


    3 years ago

    This is a very good method to convey long planks with.

    Some localities require overlong loads be flagged for safety if they exceed more than 2 feet from the vehicle. I used to carry a simple flag and "C" clamp for attaching to my lumber ends.

    1 reply

    Reply 3 years ago

    Thanks for the comment. Always check local laws. It's 4 feet here in Texas, before it requires a flag. So to be safe, I flag anything over 3 feet. If someone is closer than 4 feet to my tail, they need more than a flag..... :)