Turn Ordinary Concrete Blocks Into A Functional Rocket Stove For Your Backyard

Many of us enjoy cooking outdoors, and you might have considered one of the various kitchens you can add to your backyard. At the other end of the spectrum is a DIY rocket stove. You can build one with just a few concrete blocks. These come in several shapes and sizes, and the ones you need are the ordinary hollow type (technically they're CMUs, or concrete masonry units). They look like a rectangular figure 8.

A rocket stove works on the principle that heat is drawn through an open fire space, along a horizontal flue, and then up a vertical column. They are highly fuel-efficient and can burn small branches, twigs, or scrap wood. They give off little or no smoke, and while it's difficult to measure accurately, they can reach several hundred degrees Fahrenheit. There are numerous commercial models available, around $100. There are also several DIY examples on TikTok and YouTube. The one we're looking at today is a two-burner model put together with concrete blocks. You can cook on it using a pot or pan, or find a piece of grill or a metal tray for cooking things like burgers or steaks.

You need just five concrete blocks for this version, and four of them need no work at all. The fifth has the ends removed, and if you're a frequent DIYer, you can probably cut the concrete blocks with a tool you already own – a circular saw. It needs to look like an 'H,' but be sure to cut between the long sides. Don't cut across and shorten them, or the blocks won't line up properly. To build the DIY rocket stove, lay a whole concrete block horizontally on a flat surface. Put the cutout one on top, still horizontal, then another whole one on top of that. Two more stand vertically at either end.

That's all there is to it. As long as the blocks are snug, any small gaps will have little impact on performance. Add a few cut-up branches or bits of scrap wood to the upper cavity of the cinder block, light it, and your DIY rocket stove will soon be ready to cook on. There are lots of ways to repurpose concrete blocks around the yard, but none has the potential to produce such tasty results. The airflow can be quite loud, which is why they're called 'rocket' stoves. However, the flames can be difficult to see or may not reach the top, yet the heat can still be intense. It's best to keep kids away while it's lit.