18" Half-Moon Ceramic Heat Deflectors for XL Big Green Egg | CGS

Superior Flexibility & Outperforms One-Piece Deflectors

Our 18" ceramic heat deflectors are built for serious XL Big Green Egg cooks. The deflectors actual measurements are approximately 18.5" diameter and 3/4" thick, giving you a durable ceramic heat barrier for indirect cooking, two-zone grilling, barbeque, roasting, baking, and pizza setups.

Built specifically for the XL Big Green Egg, these half-moon deflectors work with multiple XL cooking systems, including the CGS XL Woo, CGS XL Adjustable Rig, XL EGGspander, CGS XL Spider, and CGS XL Flexible 2nd Grid setups.

More flexible than a one-piece deflector or ConvEGGtor-style plate, the half-moon design lets you cook full indirect, split-zone direct/indirect, or elevated setups depending on your rack system.

Use one half-moon deflector for a two-zone setup, or use a pair to create a full indirect heat barrier for ribs, brisket, pork butt, whole chickens, turkey breast, roasts, and other low-and-slow cooks.

Benefits of Half-Moon Deflectors

A heat deflector transforms your ceramic grill from a typical grill into a barbeque smoker or dual-zone grill by blocking direct heat and redirecting it around the food. These deflectors require a rack system such as a Woo, Adjustable Rig, EGGspander, Spider, Flexible 2nd Grid, or compatible support system to hold them.

• True indirect barbeque — ideal for brisket, ribs, pork butt, and poultry
• Two-zone cooking — direct heat on one side and indirect heat on the other
• Even heat distribution — helps reduce harsh hot spots under the food
• More setup flexibility — bake, roast, smoke, or grill with confidence
• Easier handling — half-moons are easier to move than a large one-piece ceramic plate or ConvEGGtor

XL Big Green Egg Rack System Compatibility

CGS 18" half-moon ceramic heat deflectors are used across several XL Big Green Egg setups. The deflectors are the same size and interchangeable, but how they are used depends on the rack system supporting them.

Use the links below to view compatible XL Big Green Egg rack systems. Each rack system page explains how the 18" half-moon deflectors work in that specific setup.

• XL Woo Expander
• XL Adjustable Rig System
• XL Big Green Egg EGGspander
• XL Spiders
• XL Flexible 2nd Grid Setups

Using 18" Deflectors with the CGS XL Adjustable Rig

The CGS XL Adjustable Rig gives you the most options with the 18" half-moon deflectors. You can:

• Set a pair on one of the Rig's lower two levels for barbeque cooks
• Use a pair on each of the two lower levels for double indirect setups
• Use one half-moon to create an indirect zone on the Rig's upper level

An extra Slide Guide or pair of Crossbars may be needed depending on the setup.

Using 18" Deflectors with the CGS XL Woo

In the CGS XL Woo, the 18" half-moon deflectors sit on the Woo's lower ring below the XL cooking grid. This creates an indirect setup while keeping the cooking grid at or near the felt line.

Use one half-moon deflector for a two-zone setup or a pair for full indirect barbeque smoking.

Using 18" Deflectors with the XL EGGspander

Like the XL Woo, the 18" half-moon deflectors can be used with the XL Big Green Egg EGGspander to create full or half-moon indirect zones under the XL cooking grid.

Compared to a one-piece ConvEGGtor-style deflector, half-moon deflectors give you more flexibility. Use one side for indirect cooking while keeping the other side open for direct heat, or use both stones together for full indirect barbeque setups.

Using 18" Deflectors with CGS XL Spider

Use the XL Spider and deflectors to create an indirect setup at fire ring level. The XL grid sits on the fire ring with the Spider and deflector(s) underneath. It's a popular setup for dual-zone grilling at this level.

Using 18" Deflectors with the XL Flexible 2nd Grid

Like the Adjustable Rig, the XL Flexible 2nd Grid adds a second, elevated cooking level above your main grid. The Flexible 2nd rid can sit on the XL Woo or directly on the fire ring,  with or without the XL grid.

Add the XL Half Stone Hanger and one 18" half-moon deflector to create an elevated indirect zone high in the dome. It's a popular setup for reverse sear cooks or holding food away from direct heat.

Pair vs. Full

A pair of half-moon deflectors is the most versatile option for most XL Big Green Egg rack systems.

Half-moons

• Easier to place before a cook
• Easier to remove during a cook
• Use both for full indirect barbeque setups
• Use one for two-zone direct/indirect grilling
• Use both together for pizza
• Lower replacement cost if one breaks

Full round

• Best for a dedicated pizza stone

Use as a Pizza Stone

These deflectors can double as a pizza stone, but bigger isn’t always better:

• Wide diameter stones are harder to handle and move
• Temperature control becomes more difficult

Pro Tip: If you're not a pizza pro, go 16" for a pizza stone—easier to handle with more consistent results.

Size & Specifications

• Diameter: 18.5" actual, commonly referred to as 18"
• Thickness: Approx. 3/4"
• Material: High-heat cordierite mullite refractory ceramics
• Total weight, pair/full: Approx. 13.6 lbs

Use Tips

• Place in the grill during warm-up to reduce thermal shock
• Use a drip pan to protect the surface during messy cooks
• Avoid rapid temperature changes
• Avoid placing a cold, wet ceramic stone directly into a very hot grill

Care & Maintenance

• Do not use soap or detergents
• Do not clean in a dishwasher
• Scrape debris and burn off at moderate temperatures
• Expect natural darkening from use

Don't Forget the Drip Pan

For longer cooks, we strongly recommend using a drip pan above the deflector. This helps protect the ceramic, reduces buildup, and keeps your ceramic grill cleaner.

Benefits of a Gap

On barbeque cooks, CGS Ceramic Spacers lift the drip pan off the deflector, reduce heat transfer, and help prevent burnt drippings and off-odors.

On the CGS Woo or EGGspander, 1-1/2" is the maximum lift for the CGS drip pan. Shown are CGS 2" spacers used on their 1-1/2" side for stability.

Adjustable Rig users: the rig naturally creates spacing between the deflector and drip pan. An extra Slide Guide or pair of Crossbars is needed.

This setup is our favorite for one-grid barbeque cooks in the XL EGG. It provides great airflow and direct access to the fire.

Pro Tip: On pizza cooks, use a gap between the deflector and pizza stone for more consistent pizza stone temperatures.

FAQs

How does the 18.5" compare to the Big Green Egg ConvEGGtor?

The CGS 18.5" deflector is slightly larger than the circular portion of the ConvEGGtor.

Will heat escape between two half-moons?

Yes, but the amount is minimal and does not meaningfully affect cooking performance.

Can I foil the deflectors?

You can, but creases in foil can create pinholes that may leak. Avoid wrapping the bottom side, as extreme heat could damage the foil.

Can they be used as both a deflector and pizza stone?

Yes. For pizza, we recommend parchment paper or cornmeal to help prevent sticking. Using a drip pan during barbeque cooks helps keep the deflector cleaner for pizza use.

Can I high-heat clean burn the deflector?

We do not recommend it. Using a drip pan greatly reduces the need for cleaning.

Are half-moons better than a full round?

If you cook pizza frequently, a full round is a great dedicated option. For most rack-system setups, we recommend half-moons for their flexibility.

Brand Compatibility & Product Engineering

Ceramic Grill Store is an independent manufacturer and retailer of ceramic grill accessories. We are not affiliated with or endorsed by Big Green Egg, Inc.

“Big Green Egg,” “EGG,” “ConvEGGtor,” and “EGGspander” are trademarks of Big Green Egg, Inc. All trademarks are used solely to describe product compatibility.

Since 2005, CGS has engineered premium accessories designed for compatibility with leading ceramic grills.