Insulation: What is it for your smoker & why you need it

by Joost Nusselder | Last Updated:  June 5, 2022

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Thermal insulation is the reduction of heat transfer (the transfer of thermal energy between objects of differing temperature) between objects in thermal contact or in range of radiative influence. Thermal insulation can be achieved with specially engineered methods or processes, as well as with suitable object shapes and materials. Heat flow is an inevitable consequence of contact between objects of differing temperature. Thermal insulation provides a region of insulation in which thermal conduction is reduced or thermal radiation is reflected rather than absorbed by the lower-temperature body. The insulating capability of a material is measured with thermal conductivity (k). Low thermal conductivity is equivalent to high insulating capability (R-value). In thermal engineering, other important properties of insulating materials are product density (ρ) and specific heat capacity (c).

What is smoker insulation

A smoker insulation cover wraps around your smoker to help it hold in heat.

It keeps temperatures high to ensure meats smoke properly. It can be in the form of a cover or blanket.

But how do you wrap the smoker to ensure it holds in meat? What products can you use to wrap your smoker? And what types of materials make for optimal insulation?

Read on to find out the answers to your questions and more.

Why Use Smoker Insulation?

Meat is typically smoked outdoors.

When it’s cold out, the low temperatures, chilly winds, and precipitation make it difficult for smokers to maintain the constant heat that is necessary for giving the meat its rich smokey flavor.

An insulator will hold the heat in so your meat gets smoked properly.

Insulation jackets may also keep your grill safe from combustion. If there are combustible materials near the grill, the jacket will shield appliances and structures from a fire hazard.

It will also save cooking instruments from warping and protect the underside of the grill from rust and corrosion.

An insulation jacket will be necessary if your grill consists of combustible materials like wood, polyvinyl chloride, or high-density polyethylene.

But even if your grill is not made of combustible materials, a jacket will be necessary if there are combustible items nearby.

The jacket will also protect your grill keeping it safe from the elements that can especially factor in during the winter.

It also protects you from burns.

If you touch the grill through the insulation, it will not feel as hot and it is not likely to result in a serious burn. This is good news if you have young children around.

Note, it is always best to avoid touching the grill, whether you have an insulation cover or not.

Also read: Best BBQ Smoker Gifts | 7 gifting ideas for the smoker enthousiast.

Different Types of Insulation Blankets

This section will tell you about different types of insulation blankets and the characteristics you should look for in each.

Insulation Jackets

Insulation jackets are often used to insulate vertical smokers. They feature aluminum foil insulation.

Aluminum foil is one of the most effective insulating materials because it reflects heat and conducts thermal radiation.

Insulation Blanket

An insulation blanket also uses aluminum foil insulation.

However, the jacket will have the insulation on the outside while the blanket has it on the inside.

Because both types of insulation feature aluminum, they offer similar amounts of protection.

The main difference is, the jacket lays on the grill while the blanket wraps around. Therefore, you don’t need the blanket to have a perfect fit.

Some blankets may drape over the grill while others need to wrap around several times. Ones that wrap around may have a Velcro closure to keep them in place.

Welding Blanket

A welding blanket insulates your grill just as well as an insulation blanket.

If you have one hanging around, you can use it as an alternative and you won’t have to fork over extra money to buy another device.

Welding blankets are meant to hold up to extreme levels of heat. They are made with inorganic, heat resistant fibers and can withstand temperatures that range from 300 to 2500 degrees.

Make sure the welding blanket you are using is suited to the temperature you are grilling at.

How to Insulate Your Smoker Firebox

When insulating your grill, you won’t want to cover your firebox. This will cause the insulation to burn.

However, because this is a heat source, it’s a good idea to keep this insulated as well. You can do this with a cement board.

A cement board is made of materials like clay and stone combined with aluminum, iron, silicon, calcium, and other ingredients. These are meant to withstand high heat.

Make sure the cement board is not mixed with any chemicals that can get into food.

Once you find a cement board you are happy with, here are the steps you will want to take to make sure it functions properly.

  1. Make sure there is no fuel burning in the firebox before lining it.
  2. Measure the inside walls of the firebox with a tape measure.
  3. Mark the cement board with those measurements.
  4. Place the board flat on a work table.
  5. Use a knife to cut out the piece of board you are using as marked.
  6. Repeat the process for each side of the firebox.
  7. Fit the pieces inside the firebox.

While the firebox can not be covered by a regular insulation jacket or blanket, all other parts of the grill should be covered including the cover, sides, and door.

Make Your Own Smoker Insulation Lid

If you would like to save some money, you also may consider making your own lid.

Here are the steps you will want to take.

  1. Apply strips of adhesive tape to the inside of the barbecue grill lid. Each strip should overlap the one next to it to ensure full coverage.
  2. Measure the exterior panels of the grill that need to be covered. Draw the shapes of the panels onto a thermal insulating blanket ensuring they are one inch larger than your original measurement in each direction. Cut out the shapes.
  3. Assemble the panel strips in the proper location on the grill so they are overlapping by ½” on either side. Use thermal tape to fasten the overlapped seams. Cut vent holes where necessary.
  4. Once the cover is assembled, slide it onto the grill once it has reached the appropriate cooking temperature. Remove it and set it aside when you need to tend to the food.
Joost Nusselder, the founder of Lakeside Smokers is a content marketer, dad and loves trying out new food with BBQ Smoking (& Japanese food!) at the heart of his passion, and together with his team he's been creating in-depth blog articles since 2016 to help loyal readers with recipes and cooking tips.