DIY Fire Pit with Adjustable Draft (for under $50!)

how's it going guys today i'm going to show you how to build a fire pit with an adjustable draft for under 50 bucks so the first thing we need is a good location i decided to use our old sandbox which hasn't seen much use in the past decade except for the occasional bonfire i chose this spot because aside from the house and the deck there isn't too much nearby that can catch fire and i figured the sand would make you feel like you're at the beach i cleaned it out and then determined where the center was using a measuring tape i marked this spot so i could tell where to start digging i then drew a 32 inch by 32 inch box around the central point however i would recommend making your box with sides 34 36 inches because 32 isn't really big enough to work with once you have the box marked off it's time to start digging because i built my fire pit in the sandbox i first removed all the sand and put it to the side once i hit dirt i put a tarp down so i can remove it all at the end now for me this was a very slow process because i live in new england and the soil here is horrible it's completely full of rocks and roots which is really annoying when you're trying to dig so half my time was spent just loosening up the dirt and cutting through roots with pickaxes and other hand tools here you can see one of the many rocks i pulled out of the small area i also used this flat spade to make sure that the walls were straight so our goal here is to make the hole between 12 and 14 inches deep at various points i tested if the hole was big enough using one of the cinder blocks that we're going to use later at this point it wasn't so i had to keep digging i made the mistake of adding drainage rock before checking to see if the hole was big enough which it wasn't so i had to take out all the rock and keep digging again you'll see in a minute why this hole is still too small once i was pretty sure the hole was big enough i used the spade to dig out a little section on one of the sides in the middle this hole should be about 8 to 12 inches long and just as deep as the rest of the hole later on the pipe for the draft is going to go through the space and up to the surface it's also very important to make sure that your hole is level on the bottom if it is then we can go ahead and put down a bag of drainage rock for real this time so except for the drainage rock all the materials i used for this project are in this wheelbarrow i'll include a complete list of these in the description below so now we're actually going to assemble the fire pit and the first thing i did was make the draft i took a length of metal hose that's normally used for a dryer vent which means it's heat resistant and i bent it so that i could fit inside a hole in this concrete block this block is 4 inches by 8 inches by 16 inches in total i bought 5 of these blocks that have holes through them you want to push the vent 3 to 4 inches inside the cinder block so that it will stay even when it's underground the metal vent should fit tightly inside the cinder block it's also important to make sure that there's nothing blocking airflow now position the block so that the vent is coming up through the hole in the side that we dug earlier as this block along with three others forms the foundation of the fire pit it's important to make sure that it's level if it's not move the dirt and rocks around underneath so it's level both lengthways and widthways now we're going to add the other foundation blocks these are all cap blocks which means they don't have holes in them like the first one we used it is very important to make sure that these blocks are completely level you can see here how i'm going to arrange the blocks in the fire pit in order to get the blocks as far back as possible i used a sledge hammer in a wooden post to push them however in some areas the hole still wasn't big enough so i had to keep digging when you arrange these blocks they should be corner to corner with only a slight amount of overlap it's a little hard to explain but when you overlap the blocks the center area should still be a square not only did the blocks have to be level but the inside corners should be as close to 90 degrees as possible it's very important that you get these two things right because if you don't the fire pit will look slightly off from the top once i was happy with the orientation of these four foundation blocks i put in one square paver in the center then i built the walls using concrete blocks with holes in them the reason i use these and not the ones that are solid is because these are slightly cheaper if your four foundation blocks are lined up the right way the wall should go into place very easily here you can see what the overall structure of the fire pit looked like before i filled in the dirt then i carefully added dirt around the concrete blocks to fill in the hole i didn't fill it all the way up though because i'm just going to put sand on top now before you put in the dirt around the draft it's important to make sure that you block off the holes i was going to use this concrete patch but i realized i didn't have enough time so i just used some rocks and gravel instead using rocks isn't the best solution but it's better than nothing i also put this curved rock i found on top of the vent to help prevent it from getting crushed then i filled in the rest of the dirt the vent i bought was actually too long so i unwound it and then cut the piece off it should be just long enough so that it's flush with the ground i also bought this little drainage cap which actually fits perfectly on top of the tube [Music] i kept adding soil until i only had a couple more inches to fill [Music] at this point i scooped in the excess sand that i had removed at the beginning i packed it down so that it was flush with the edge of the fire pit to finish it off i put some decorative pavers on top so you wouldn't have to see the concrete blocks as you can see here i put three small ones and one big one on each side and it was a pretty good fit and then you're done when i was finished i removed the dirt and ripped out the sand that was left i also decided to add a new bag of sand just to freshen it up a little bit this project took me two days but if you were to do it in an area with less roots i'd say you could get it done in one afternoon once i was happy with how it looked it was time for the inaugural fire first i crumpled up a bunch of newspaper and other types of paper and threw them in the bottom of the hole next came the strips of cardboard on top of that i added sticks and twigs in the shape of a teepee and finally i placed small pieces of wood also in the shape of a teepee i added bigger logs once the fire got going then to start it i lit the paper at the bottom i lit both sides and after a couple seconds the flames started to spread it didn't take long at all for the fire to completely ignite the flames that came out of the fire pit were surprisingly tall and the fire threw a lot of heat and seem to burn very efficiently as for the draft you can adjust the amount of air going into the fire by using another paver at this point the fire is burning so well it's hard to see a difference between when the draft is covered versus when it's not but you can definitely feel air getting sucked into the draft if you put your hand on it just a quick note about why i put the draft where i did as the fire burns and air inside the fire pit rises cool air from the surface gets sucked down so by adding a pipe straight from the surface to the bottom we create an easy channel for fresh clean cool air to get to the bottom of the fire thus keeping the fire oxygenated my design is based on what's called a dakota fire hole which are supposed to burn very efficiently with very little smoke and so far i would say that my fire pit meets both of those goals if you wanted to you could build a fire pit without the draft it would save you about 15 bringing the total cost to 35 or 40 bucks however in my opinion the draft is worth it this has been a munchkin robot how-to video thanks for watching if you have any questions ideas about how i could improve the design or suggestions for future videos please let me know in the comments below also don't forget to like subscribe and share with anyone who you think would find this interesting you

Channel: Brendan Chapuis

Views: 2,352,340

Rating: 4.8128815 out of 5

Keywords: fire pit, diy, fire, outdoors, build, project, MunchkinRobot, home improvement, how to make a fire pit, how to, tutorial, summer, make a fire pit, homemade, fire pit ideas, firepit

Id: m7HzpgebAHs

Length: 8min 54sec (534 seconds)

Published: Wed Jul 26 2017

Reddit Comments

[u/TheRoostar]

Great project, cool video.

To qualify my next statement I should mention that I've worked for a concrete paver manufacturer for 10 years.

If anyone plans to do this at home I strongly advise against using any sort of compressed concrete paver at the bottom of the fire pit. They absolutely can explode.

A typical concrete paver is compressed to a minimum of 8000 psi to meet ASTM standards. This means they are not very porous. ASTM also requires a maximum absorbtion rate of 5%. That means they shouldn't hold much moisture but they can still hold onto some.

If a paver is saturated, and then rapidly heated, the expansion of said moisture can cause them to explode due to the low porosity.

I love the project, and I'd love to sell more pavers, but I'd rather see it built safely.

I would recommend a clay brick or a fire brick over concrete pavers for the bottom.

[u/tyhatts]

Nice work !! Just FYI...The blocks are going to cave in over time due to the pressure on the back side from the dirt. Looks good now. Next spring, you'll be re-doing it.

[u/Titan_Hoon]

Looks nice overall but watching you dig was painful! For the love of god if you do anymore digging go on amazon and buy a fiskers digging shovel. After you get it take a file and sharpen the leading edge of it, this is by far the most important step. You will be able to cut through 90% of those roots with ease.

[u/storm-bringer]

I adjusted the draft in my fire barrel by shooting more holes in it.

[u/munchkinrobot]

Update: Wow this post this post got a lot bigger than I was expecting. Thank you all for your feedback and advice!

One thing that's really important that you all know before building a fire pit like this is that there is a chance that the paver I used at the bottom of the pit could explode if heated. According to someone who has worked for a concrete paver manufacturer for 10 years:

The cinder blocks are probably fine, however the red square at the bottom of the pit certainly could explode. The difference is that the red square is likely compressed to at least the ASTM standard 8000 psi, which means it's not very porous. Basically, if it were to soak up some moisture and then be rapidly heated to the point of creating steam it could potentially pop.

They recommend using something like fire bricks instead. Just remember that this post is for information purposes only, and I'm not an expert.

[u/mystrymaster]

Nice work, I am looking at doing my own firepit on the cheap. You said you were up in New England so do you have any concern about the pit flooding when it rains, or the cinder blocks ability to stand up to the elements?

[u/quazifrog]

A note about the dryer hose that you used as a draft; it would have been easier to stretch it out by simply putting a 2x4 into the end and using a mallet to could shape the hose.

[u/draginator]

As someone from CT who built a house on undeveloped farmland 25 years ago, fuck rocks.

[u/squeevey]

how long do you anticipate that flex pipe to last? I feel like it'll corrode out in no time.