DIY Weber Kettle Extender: Double Your Cooking Space

Want to double the cooking space on your Weber kettle without paying £120 or more for a shop-bought extender ring? Me too. In this post I’ll show you how I built a DIY Weber kettle extender using a rotisserie ring, four stainless bolts and a drill. I’ll also show you how I fitted a proper lid thermometer to my 20-year-old Weber, which has never had one.

ChefsTemp sent me the S1 and Breezo to try. All opinions are my own. This post also contains affiliate links, so I may earn a small commission if you buy through them, at no extra cost to you.

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Why Your Weber Kettle Runs Out of Space

Here’s the problem. When you cook indirect on a Weber kettle, your coals take up half the grate. That’s fine if you’re only cooking one bit of meat. However, if you want sides or a second protein on there too, you run out of room fast.

Extender rings exist to fix this. In the States, there are loads to choose from. Here in the UK, though, I’ve only found a handful, and they come with a hefty price tag.

So I wondered whether I could make the rotisserie ring I already owned do the same job. It turns out I could.

Turning a Rotisserie Ring Into a Weber Kettle Extender

I used the enamelled Onlyfire rotisserie ring, which fits 57cm kettles. The idea is simple. You drill four holes around the ring and bolt in supports, and a second grate sits on top. Your original grate stays at its normal height, so you lose nothing and gain a whole extra level.

Rotisserie ring marked with masking tape for a DIY Weber kettle extender

What You’ll Need

Important: only use stainless steel bolts. Zinc-plated or galvanised bolts can give off harmful fumes when they get hot.

Step 1: Measure and Mark

The ring is 57cm across, which gives a circumference of roughly 179cm. Divide that by four and you get about 44cm between each hole. I marked mine about 3.5cm down from the top edge, which matched the drop on my Weber nicely.

Step 2: Tape Before You Drill

Put masking tape over every spot before you drill. This matters more than you’d think. Enamel is basically glass on steel, so if you drill straight into it, the coating shatters. Moisture then gets in, the metal rusts, and the coating flakes off.

Step 3: Pilot Hole First, Then Go Bigger

Start with a small bit so the big one doesn’t skate about and scratch everything. Then step up to the full-size bit. Go slowly and let the drill do the work.

Step 4: Fit the Bolts

Push the bolts through, put the nuts on the back, and tighten them until they’re snug. Don’t over do it, though, because you’re tightening against enamel and you don’t want it cracking.

Step 5: Test the Fit

Put the ring on the kettle, drop in your lower grate, then sit the upper grate on the bolts. I ended up with about 10 to 11cm between the two levels. That’s a whole extra cooking space.

Weber kettle extender with two cooking levels using a rotisserie ring

What About the Gaps in the Ring?

The rotisserie ring has openings for the spit and motor. For now, I’m blocking them with foil while I test the idea. Longer term, I’m looking at heat-resistant magnets or custom silicone plugs. I’ve already 3D printed some prototypes.

Fitting a ChefsTemp S1 Lid Thermometer

My Weber has never had a lid thermometer. For 20 years I’ve cooked on vent position, gut feel and a meat probe. Since the drill was already out, I fitted a ChefsTemp S1.

It connects over Wi-Fi and Bluetooth, and it’s USB-C rechargeable. Better still, it puts your BBQ temperature and your meat probes in one app, instead of having me switch between two.

I measured between the vents and the lid edge and placed it about 9.5cm down. That’s close to grate level, but clear of the food. I used the same method again: tape, pilot hole, then the bigger bit. Be warned, though, the lid was much harder to drill than the ring, so take your time.

A quick warning: drilling your BBQ may void your warranty. Mine is 20 years old, so that ship has sailed. If yours is newer, check your warranty first.

Testing Temperatures on Both Levels

Indirect Setup

I lit a full chimney for an indirect cook, with an Inkbird probe on each level and the S1 on the lid. As expected, the top grate ran hotter, at around 142 to 147°C, while the bottom sat around 124°C.

That difference of roughly 20°C is useful. You could run a pork joint low and slow on the bottom for pulled pork, with ribs on top. That’s exactly why I wanted to do this.

Kamado-Style Deflector Setup

Next, I tried two baskets of lit coals with two halves of a pizza stone on the lower level as deflectors. With the vents fully open, the S1 climbed to 183°C, while the Inkbird read about 40°C lower. I’m still working out why, but I’m inclined to trust the S1.

Before anyone comments, I know this isn’t a real kamado. A ceramic kamado holds heat far better than a Weber. Even so, the amount of food I can now fit on this kettle will rival one any day of the week.

Is This DIY Weber Kettle Extender Worth It?

If you already own a rotisserie ring, absolutely. The bolts cost me about £5, and I’ve saved myself the £120 or so a shop-bought extender ring costs. It also takes up less space in the shed.

Are there limitations? Yes. The two levels will always run at different temperatures, because that’s how heat works. Still, that’s true of any extender ring, and you can use it to your advantage.

As for the ChefsTemp S1, for a kettle that never had a lid thermometer, it’s a no-brainer. I’ll save my final verdict until I’ve done a proper long cook with it.

Kit Used in This Video

BBQ Gear

ChefsTemp

Tools

Some of the links above are affiliate links. If you buy something through them, it costs you nothing extra, but I get a small bit of commission that helps keep the channel going and the BBQ fired up. Cheers if you do! As an Amazon Associate, I earn from qualifying purchases.

Season It Properly

Now you’ve got double the space, you’ll need double the seasoning. My hand-blended Pitmaster BBQ Rub is made for low and slow pork. Grab it, along with the rest of my range, in the Chef Bobby’s Kitchen shop.

Would you drill your rotisserie ring for double the cooking space? Let me know in the comments, and subscribe on YouTube for more.

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