How to Build a Finnish Gap Fire (Rakovalkea) Step by Step

Knowing how to build a fire is a critical skill, but knowing how to build one right, and to build the right one for the situation at hand, separates the beginners from the seasoned pros, and it might separate the survivors from the casualties.

Choosing the right kind of build, or lay, for your fire will make the most of your fuel, help you get more work done, and even help you stay more comfortable no matter the situation. One of my all-time favorites is the Finnish gap fire, called the Rakovalkea. It looks primitive, even crude, because you are basically burning two sizable logs whole.

But the design has a lot to recommend it. It can throw out a ton of heat, it’s easily adjustable, and it burns for a very, very long time, meaning you won’t have to get up during the night to stoke it.

Keep reading, and I’ll tell you everything you need to know to prep and build the Finnish gap fire for yourself.

Best Wood to Use

This is a fire with a long and distinguished history of use throughout dry Arctic climates. Accordingly, pines and other softwood trees, often standing dead trees, are the most common type of fuel for it.

Now, as you might expect, you can use nearly any kind of dry, seasoned wood with good success here. If at all possible, you should avoid wood that’s saturated or green because it won’t burn as readily, and it will be incredibly smoky.

As always in a survival situation, you should use what you’ve got. That’s another perk that this type of fire has going for it: if you can find smaller dry fuel, you can use it to help dry out the larger logs over time.

Supplies

Small Logs: You’ll need two logs for this fire, anywhere from 4 to 6 feet long for best results. Bigger logs will burn longer, but they are obviously much harder to transport, and they take more time to prep. Logs that are 8 to 10 inches in diameter are a good balance of portability and performance.

Large Branches: You’ll need a few thick branches or small tree trunks to serve as supports and spacers. These should be straight and anywhere from four to six inches (12 cm) in diameter, depending on the diameter of your logs.

Bigger logs will benefit from slightly larger branches. You’ll need four individual branches the same size that are about 16 inches (40 cm) long each, or a longer trunk or branch that you can cut to size accordingly.

Longer, Thin Branches, x2: A pair of three- to four-foot branches about as thick as your wrist. You’ll use these to support the logs and keep them in place once you have the fire built.

Tinder: Yes, you’ll still need tinder to get this fire going. Use anything you’ve got, homemade, commercial, or scavenged from the environment. Feather sticks, dry leaves, bird’s nests, dryer lint, whatever.

Kindling: Larger fuel in the form of smaller sticks, branches, and large splinters that you hack off the logs works perfectly in this situation.

Tools

Axe or Hatchet: This is really all you need to prepare this fire. From felling the trees, if needed, to carving the channel for the kindling and notches for the supports, a little bit of skill with a good, sharp axe or hatchet can get the job done.

However, you must know what you are doing and be very careful because there are some challenging, and some would say risky, cuts to be made during the process. I’ll walk you through what you need to know when we get to the instructions.

Adze (optional): If you have one, now is definitely the time to break out the adze. This will make cutting the channel and notches far easier and quicker than doing the same with an axe alone.

Saw: A saw, of whatever kind, definitely comes in handy for this project. It will let you easily cut your branches to a uniform length with very little effort and get better, cleaner results than trying to chop through them.

Nail: Yep, one single, solitary nail. You’ll need this to nail one of the supports to the top log after you have everything built.

Lighter or Fire-Starter: Something to actually get the fire going. Use a lighter, ferro rod, or anything else you want.

And that’s absolutely everything you need. Time to get down to the actual business of building this fire and getting it started.

Instructions

Step 1: Gather and size logs and branches. Assuming you don’t already have your wood on hand, take the time to forage for suitable pieces, cut them down, and then cut them to size. Use your saw if you have it.

Step 2: Shape end of long, thin branches into points. Using your axe or hatchet, carefully chop one end of each long, thin branch into a point so you can more easily drive it into the ground.

If the wood is soft and your tool very sharp, you can whittle it in hand. If not, you might need to brace the wood on a stump or rock as you do this.

Step 3: Cut perpendicular notches into ends of each log. Roll both of the logs into position where you can work easily without them rolling away.

In one log, cut perpendicular notches into either end, six to eight inches from the end, that will fit the larger branches snugly. Roll that log over and repeat the process on the opposite side. On the other log, repeat the process on just one side.

Do good work here because a proper fit will make the fire more stable and easier to control later.

Step 4: Check for fit with large branch sections, set aside. Grab your large branch sections and check them for a good fit in the notches that you just carved out. Ideally, the branches will be stable and lie parallel with each other. Make any adjustments you need to on both logs right now before moving on.

Step 5: Carefully carve lengthwise furrow into center of each log. Going end to end on each log, use your axe or another tool to carve a channel several inches deep. This channel should have a shallow U or V profile.

Caution: This is a deceptively dangerous job with an axe or hatchet. Resist the temptation to straddle the log and strike it between your legs. A deflection here could inflict a serious wound on your legs or feet that is difficult to avoid.

A better plan is to stand to one side or the other as you chip away at it, or kneel over the log, riding it like a horse, and then strike at arm’s length.

Step 6: Set bottom log on support branches. Once you have the channels carved, set the bottom log, that’s the one with two sets of notches, down on the larger branches with the channel facing up toward the sky. The branch sections act as feet that help keep the log up off the ground and also prevent it from rolling away.

Step 7: Place tinder and kindling along length of notch in bottom log. With the log secured, now it’s time to start placing kindling along the length of the channel and a few strategic bundles of tinder. Stop just short of the notches on the upper surface.

Step 8: Drive support stake into ground at one end. With the first log in place, grab one of the long, thinner branches and drive the sharpened end into the ground. Place it so it’s just inside one of the feet and touching it and the log. Pound it with a rock or, carefully, with the poll of your axe to get it deep enough.

Step 9: Set upper log in position on “spacer” branches. Check for fit. Set your two remaining short branch sections in place on the lower log. Now hoist the other log into position over the first that you have prepared and set it into place on those branches with the channel facing down.

It should look roughly like what you see in the picture here:

Give everything a shake and wiggle to make sure it is secure and won’t fall apart or roll away.

Step 10: Carve spacer branches into wedges, if desired. If you have the time, energy, and inclination, you can remove the upper spacers between the two logs and taper them.

Doing so will allow you to adjust the spacing between the logs, which will give you more control over how quickly and how hot they burn by pushing them further in or pulling them out. This is optional.

Step 11: Secure upper log on opposite end and side with other thin branch. Once everything is the way you like it, it’s time to secure the upper log in place for safety.

Grab your other long branch with the sharpened end, go to the end and side of the logs opposite the first support that you put in, and drive it into the ground at an angle so it holds the upper log down:

When it is snug, drive a nail through the branch and into the upper log:

Ok, so this is what the final structure looks like:

Step 12: Light tinder. Time for the big moment! Grab your lighter or other firestarter and go along the length of the logs, lighting the tinder bundles. They should catch fire readily, ignite the kindling, and soon set the logs ablaze.

Step 13: Fan and adjust spacing of logs to control fire. Use a piece of bark, folded tarp, or anything else to fan the flames and intensify the fire. If you tapered the spacer branches, carefully move them in or out to adjust the spacing between the logs and better control the fire. IMG_1619

Step 14: Add kindling as needed. The fire should be going well right now, but with green or damp logs, you’ll need to add kindling over time and as needed to keep them going.

Step 15: Enjoy! You are all done. You can now cozy up to a fire that puts out a ton of heat and will burn for a very long time.

Helpful Tips

• This type of fire is ideal for warming several people easily around a campsite and putting out tons of light, but it’s less suitable for cooking.
• This fire can burn very intensely, making it difficult to get close for adjustment or adding kindling. Use tongs, a long branch, or similar tool to help you.
• Compared to more common styles of fire, this one can prove very difficult to extinguish, especially if you’re trying to use sand or soil. If at all possible, keep a couple of large containers of water nearby for emergency purposes.