There is one important thing to consider in the planning phase of your future pergola, gazebo, or covered porch: Combustible Clearances

I have personally taken many calls from customers who have built an outdoor-entertainment area and piped gas in for outdoor heaters. I have disappointed many of those customers when I have informed them that their combustible clearances are too low for gas patio heaters. Here are some rules of thumb to consider when designing your heated outdoor structure:

  • The lowest part of the lowest power overhead gas patio heaters typically should be at least 8' above the floor or ground below it.
  • Most overhead gas outdoor heaters are 8" to 12" tall.
  • For the greatest flexibility of patio heater models and to maintain the ability to tilt the heaters allow 18" above each heater to the closest combustible surface.
  • That equals up to 30" (2½') from the closest combustible above to the bottom of the heater.
  • In short if you have 10½' or more from the bottom of combustible surfaces above where the overhead gas patio heaters are going to be mounted and the floor then you have maximum flexibility.
  • The minimum flexibility for a gas patio heater is with the Habanero M20, pointed straight down with a low-clearance mounting kit. This has a 3" top clearance and is about 11" tall. With this you could get by with a 9' combustible clearance, so long as the heater is not mounted directly over stationary people's heads. Ideally it would be mounted over a table.

If local codes (or other considerations) prevent you from building so tall a structure, there is still hope. You can use 240 volt overhead electric patio heaters, which have lower clearances from combustibles, and are typically thinner than the overhead gas heaters.