Hi Christy and Cindy,

We'd suggest starting with a phonecall to Timbertech and see what they recommend. As a general rule of thumb composite decking does not react well to heat. I believe Timbertech is made up of some percentage of plastic (again not positive, but a call to them should answer the question) and heat transfer down metal legs of a firepit could melt your decking. As far as poured concrete goes, we'd recommend checking with Timbertech, a local engineer and your local building codes to first make sure your deckboards and the deck structure itself can handle the load of the additional weight.

Since we're on the topic of decking and fire....... a tropical hardwood decking material like Ipe has a class A fire rating which is the same as concrete. Of course it, like any other material, will eventually catch on fire, but if one is thinking about building a deck that is to include a fire feature then they should consider using a tropical hardwood like Ipe.

Best of luck and let us now how it goes. As always share some pictures of the finished product!