Consider When Designing Your Heated Pergola

Consider When Designing Your Heated Pergola

Posted by Alfresco Heating on Oct 23rd 2014

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 7.5" 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.