Introduction: Insulated Sleeping Pad (thermarest)

About: Not a hacker, just a hack.

As the end of summer rolls around, I've started to think about ways to extend the camping season. My friends have noticed that I've gotten a bit enthusiastic (read: obsessed) with getting outdoors as much as possible this summer, and up in Canada, things start to get pretty chilly at night, even in August.

I have two sleeping pads that are pretty good, an inch and a half thick, but they don't have any insulating properties whatsoever. Anyone who's slept on the ground knows that if it's cold, it'll sap the heat right out of you. Thus, the problem was defined:

How can I add insulation to my sleeping pad without adding bulk?

There are some good YouTube tutorials about adding insulation, but they all end up with a much thicker pad, or even a second pad. When I'm trying to pack ultralight, that's not something I want. The solution can be found at your local dollar store, and it only takes about 10 minutes to create.

If you've got 5 bucks, you can do this in 10 minutes. Minus the travel time to the store, of course.

Step 1: Materials

Obviously, you're going to need at least one sleeping pad. I have two. But if you're reading this, I'll assume you already own one, and I won't add it to the bill of materials.

Materials:

  • Emergency Blanket: can be found at the dollar store for (you guessed it) a dollar, or online.
  • Tape: I used packing tape because it's what I had on-hand. Can also be found at the dollar store.

Tools:

  • Scissors: Again, can be found at the dollar store if you don't have a pair already.

Total Cost: If you don't have any of the above, I'd estimate that it'll be less than 5 bucks. Grab a candy bar to keep you fueled up.

Oh, and while you're there, pick up a few extra emergency blankets. One in the first aid kit, and a spare to keep at home.

Step 2: Cut Your Blanket

Your emergency blanket should be big enough to handle covering two standard-sized sleeping pads. Lay the blanket on the floor, and place a sleeping pad on one side of it. Then, fold the other side over to check if it'll cover the pad on both sides. If it does, you've got enough material to cover two pads.

Using the fold lines left from unfolding the blanket, cut the blanket into two equal halves lengthwise. Place one half to the side for later.

Step 3: Wrap the Center First

We're going to use the packing tape to create a few bands that go across the middle of the pad, in order to prevent it from sliding around. It's hard to show in the photos, but in this step, we're going to wrap the tape with the sticky side facing up, away from the pad. This lets us make the insulator removable, and won't leave any sticky residue on the pad. We're going to start from the middle, and finish up the ends in the next step.

  1. Start at the middle of the sleeping pad.
  2. Pull some tape off the roll, and lay it on the sleeping pad with the sticky side facing up, and the end of the piece of tape at the edge of the sleeping pad. Don't cut the tape yet.
  3. Gently lift and pull the edge of the blanket over the top of the pad and tape, and press it down onto the sticky side.
  4. Now we need to cut the tape at the width of the sleeping pad. Pull off enough tape to cover the underside of the pad, and cut the tape. Keep a finger pressing down on it so it doesn't fold back up on itself.
  5. Again, gently lift and pull the opposing edge of the blanket over and onto the tape. You want it snug, but don't apply too much force.
  6. Now move halfway from the end of the pad, and add another band.
  7. Do it a third time, so you will now have a band going across the middle, the top half, and the bottom half.

Step 4: Finish the Ends

Now it's time to wrap up the ends. Fold the end as if you're wrapping a gift: the edges go in first, then fold up the end. Make a mental note of where the end covers the sleeping pad, then unfold the end.

You're going to run a piece of tape, sticky-side-up, from edge to edge at the point where the end will be once it's folded up. Use the same process as in the last step: cut a piece long enough to span from edge to edge, lay it sticky-side-up on the sleeping pad, then lift and fold the edges up onto it.

Now simply fold up the end, and attach the overlap to the sticky side of the tape. You may want to add a couple of small pieces for the edges where they're folded a few layers thick. Once it's nicely laid out, run a second piece of tape over the folded edge and sticky-side-up tape to make a double layer of tape, with no sticky exposed.

On one of the corners, you'll need to cut a relief for the valve. Simply use your fingers to find the valve, and use your scissors to gently cut the insulating blanket around the valve. Be sure not to cut the pad itself! Once you've got a relief cut, use some more tape to finish the edges so they don't tear.

Step 5: Cover Up the Tape

Now that the ends are finished, we can cover up the exposed sticky tape surface in the bands running across the middle of the pad. Take your packing tape, and just run a new strip facing down onto the existing strips.

Step 6: Roll It Up!

You're now done! Open the valve to let the air out, and roll up the pad with the insulation facing up. You'll want to roll it so the insulation is facing up and in, to avoid putting undue stress on the blanket itself.

That wasn't so hard, was it?

Now get out there and camp until the snow comes!