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Martin, Electrical Engineer
Category: Home Improvement
Satisfied Customers: 4944
Experience:  Design, construct, fix and grow stuff around and in the home.
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I just hired a mason (and his team) to install some

Customer Question

I just hired a mason (and his team) to install some limestone. He will be installed 27' of bench, some columns and a wood burning fire pit. His bid was about 1/3 of another guys, but my general contractor knows him and says he does a good job. My concern is what to look out for on the fire pit. He will be installing a fairly large pit (5' OD) on a fairly recently laid stamped concrete patio (2 months old). I'm an engineer and I know that since he is cheaper he may not know all the rules for installing a fire pit on concrete. I know that most concrete does not stand up to high temp. What are the rules for such an installation that I need to make sure he follows? I'm assuming firebricks on the bottom and sides(I'd personable prefer no metal)? The stone he will use will be limestone, fairly large pieces. Should he put in a weep hole for drainage? Different motor? I'd love a check list to make sure the installation is going properly and I can stop the install if I don't agree.
Submitted: 2 years ago.
Category: Home Improvement
Expert:  Martin replied 2 years ago.
Hi. The first thing to look for is if your pit is in accordance to you city regulation. They usually have distance from building to respect and maximum diameter also flame height.
It indeed do not stand up. A lot of stone churches here that burned need to be completely demolished because even if the wall still seem intact, the rocks are all cracked and the mortar is chemically not bonding like it should anymore.
Firebrick is indeed the way to go, but simple sand and/or layer of wood ash do quite a good insulation (traditional Japanese Irori are no more complicated than that). Drainage is needed for any structure that may freeze in winter. In case of a fire pit in stone, water should be kept at a minimum because soaked stone can explode with heat. That said, you can have filty residu from that, tar especially that can stain, so plan something to collect those.
I am not sure why a motor is needed, for the initial oxygen intake? that is better done with a little battery fan. If you mean a motor to turn meat over the fire, it should be far away at the end of a long rod/shaft.
Try to have him make it easy to destroy, nobody want to be stuck with something they hate to use in the end. Fire pit are fine when enclosed but when wind start they blow smoke on everybody. Personally if i was to build an external heat source, i would prefer a rocket stove.