Hammock Underquilt




Introduction: Hammock Underquilt

While gearing up for the camping season I realized I needed an underquilt. Those of you viewing this instructable can probably guess why. For those of you who don't like guessing games, to put it simply, it gets cold at night when your just hanging around.

Sure I could have got an ultralight underquilt from amazon, but I was appalled by the prices. Granted, its justifiable to invest in good gear, but I thought "I could make one cheaper", so I did.

Welcome to the $27.00 hammock underquilt instructable.

Step 1: Pre-Planing

After doing a bit of research on hammock underquilts, I learned 3 things.

  1. Lots of people make their own.
  2. There are quite a few different designs, both retail and diy.
  3. I can't count.

Material: I decided upon using a sleeping bag for the underquilt material. They are weather rated, pre-filled, compressible, easy to find, and as a perk they come with a stuff sack.

Suspension: Referring to my hunt for knowledge above, I hoped on amazon to see how conventional underquilts were suspended. I noticed a lot of retail underquilts used 'shock cord', so that's what I decided to go with.

Step 2: Gathering the Materials

So... once I decided to actually go forth and build things, I had to get the 'stuff'.

Sleeping Bag: I was able to find a very cheap sleeping bag at my local Walmart for $9.00. Its a warm weather sleeping bag rated for 40-60 degrees. They also had a youth sleeping bag for $4.00 that I Imagine would work well also. The dimensions of the sleeping bag are, 66" x 75" x 2" (fully open).

Shock Cord: I sourced mine from Joan fabric, sold by the yard. However, Ebay sells 25' of elastic shock cord for $8.00.

Nylon Strap: Since I was at Walmart, I found the strap there. Again Ebay sells 15' of 1" Polypropylene Webbing for $8.25.

Materials List

  • 1" Polypropylene Webbing / Nylon Strap (15').
  • 1/8" Shock Cord (17').
  • Cheap sleeping bag.

Please note a sewing machine was used in the process of making this underquilt.

Step 3: Sleeping Bag Prep

The very first thing I did was tare into the sleeping bag. I opened the bag, took a great big whiff of new camping gear, then got to work.

Removing All The Unnecessary Bits: I grabbed my seam ripper, and removed the zipper. I did in fact remove the zipper the "proper way", this was in an effort to preserve the sleeping bag as much as possible.

Once the zipper was removed, the tags, elastic straps and logo just fell off. So now that's done, off to bigger and better things.

Summery: We now have a 66" x 75" stripped sleeping bag.

Step 4: Adding the Suspention Tabs

While I was sewing, I didn't think to take pictures, so we will have to make due with illustrations. Fair warning, I'm no artist.

Cutting The Nylon Strap: I cut 26 pieces of nylon strap, each exactly 4" long. I then melted the ends with a lighter to prevent unraveling.

Stitching It Up:

6 tabs were stitched on both 'sides' of the sleeping bag, I used the seams as a guide. Theses were approximately 11.25" apart. This also reinforced the seems a bit.

7 tabs were stitched on both 'ends'. Theses were approximately 11" apart.

Please see the image outlining the tab placement for more details.

While placing the nylon tabs, I allowed myself 1.25" for stitching, this gives the shock cord plenty of room.

Step 5: Running the Cord

While researching, I couldn't find a definitive way to run the shock cord, this is how I ended up doing it.

Main Idea: The main idea behind using the shock cord is simple, it allows for movement. Since no load is directly placed on the underquilt, the elastic cord is perfect for this application. The shock cord works great at supporting just the underquilt, while keeping it tight to the hammock, which is what we want.

Getting Ready: Cut the elastic shock cord into 4 pieces, 2 should measure 24" in length, the other 2 should measure 80" in length (or 1 piece at 160" if you have knot phobia). Please see the image detailing this step.

Doing It: Two pieces of 80" shock cord run though the 'side' tabs, and 'corner' tabs (each side). The cord is tied off at each end. This supports the sides of the quilt, it should be taut, but have enough stretch to allow you to get in and out of the hammock. Trial and error maybe necessary for this step.

The two pieces of 24" cord should be ran though the remaining 'end' tabs, then tied off. This helps to further support the quilt, and "gathers" the end together while still allowing movement.

Step 6: Finishing Up

Well, that's it, piece of cake! The only thing left to do is test it. The ends get clipped onto the carabiners where your hammock is attached, no need for a guyline.

*Note: My hammock was 9' long, your shock cord length may vary based on the size of your hammock.

Stay warm, and thanks for viewing my instructable.

1 Person Made This Project!


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2 years ago

A (rather) simple solution, an instruction which is fun to read and even some hand drawings on graph paper! You made my day better.


2 years ago

Sweet post. Your hammock insulator solution is much less trouble than my contraption. I modifies my Hennessy Hammock by sewing an extra layer of cloth on the outside of the bottom. Then I stuffed a pad in between. It wasn’t so much a warmth thing as placing a barrier so the mosquitoes couldn’t bite me through the tight nylon. I will be making one of your design this weekend. Thanks for posting.

Don Barthel
Don Barthel

Reply 2 years ago

I also have a Hennessey Hammock but the entrance is on the bottom. So how do you plan to enter the hammock if the quilt is in the way?


Reply 2 years ago

When I sewed the extra layer of cloth to the bottom of the hammock I made was just making a pocket like place to put a pad to protect my back from the Alaskan Mosquito bites. They will bite through stretched nylon. I sewed the pocket surface to the edges of the access slit on the Hennessey Hammock. Then I split my protective pad to fit. This meant that the pad slid in only from the head end. I made sure to include a flap to make sure the pad didn't slip out while I was asleep. Did that make any sense?

The design described in this Instructable will require bunching up the foot end of the underquilt towards the middle. Once inside the Hennessey Hammock there will be some gymnastics required to pull the bunched up quilt toward to foot end of the hammock. Exiting the hammock will be another adventure. I'm sure I will manage.


2 years ago

I had the same idea with an old child size sleeping bag. it worked ok but didn't stay snug up against me in the hammock because I had just made attachments on the ends. I will be pulling it out and redoing it the way yours is designed. Thanks for the instructable


2 years ago

This is a great idea for a hammock mod! It makes so much sense, I just never considered that you may need one!