What materials must I use if I plan to install a fireplace? As far as I understand, it must be something heat resistant.

I think that now it is not necessary to build everything yourself, and it is quite enough to find some company that will manufacture, deliver and completely install your fireplace. I can definitely recommend the outdoor fireplace for sale by capofireside. I've heard a lot of good reviews about these fireplaces, and besides this, on the site you can find many different options from laconic to very stylish.