This characteristic of fire is not unique to wild fires, but is the same regardless of the size of the blaze. The intense heat and variations in temperature have the effect of wearing down and destroying materials, even strong materials such as steel.
But there is something else working at destroying your fire pit along with the forces of the actual fire. Exposure to wind, rain, and temperature changes also has an effect. Weather can erode and rust steel relatively quickly, even without the help of fire.
An outdoor fire pit is the worst case scenario. It is a combination of direct contact with live fire, and exposure to all the outdoor elements, often year round. This combination effect is powerful, and inferior fire pits can break down very quickly.
So how do you know if your fire pit is built strong enough to endure the forces of both weather & fire?
This is the simplest way to tell if you fire pit is going to last. The fire pit is going wear over time, there is no way to avoid this. The question is how long until it wears out. This correlates almost exactly with the weight of the fire pit. The reason for this is that a lighter fire pit will have lighter gauge steel in its construction, which is much more likely to rust through in a shorter amount of time.
How much weight is good? Well it depends on whether the fire pit is made out steel, 430 stainless steel, or 304 stainless steel.
If its normal steel with a high-temp coating, you really need a heavier fire pit.
For 430 stainless, figure about the same as regular steel because once 430 is exposed to the high heat of a wood fire, it starts to breakdown similar to normal steel.
304 stainless is the ultimate material for withstanding both weather & fire. With this material a fire pit a fire pit will last longer, but remember it is still going to breakdown over time so a thin, tinny wall will break through eventually if it is not heavy gauge steel.
When researching your fire pit purchase, make sure to ask the manufacturer specifically what the wall & bottom material is made out of. While some firepits claim to be made from 304 stainless, they often use 430 for the bottom or walls. The problem with this is that those are the parts of the fire pit that rust that fastest! Make sure you know the wall material of your fire pit if you are paying for a “stainless steel” model.
Additionally, be wary of any mesh screens covering your fire pit. Unless made out of 304 stainless, a screen will break down very, very quickly. This is because the fire can heat up the metal from all sides, and there are hundreds of points of failure in the mesh. Even with a stainless steel mesh, make sure to never store the screen outside. The combination of heat & rain will kill it in very short order.
There you have it! When buying a fire pit pay attention to the material and especially the weight of the unit. Make sure you know what the bottom and sides are made out of, and remember that no matter what fire pit you buy, it’s going to take a beating!