Gym Ball Pizza Oven for less than $250 - Part 1

This is the first part of putting together a pizza oven. I built this dome using Perlite, Cement, a gym ball, couple bucket cutouts, and a 4’ x 4’ x 1/2“ plank. All for less than $60. Perlite used: =sr_1_3?dchild=1&keywords=perlite&qid=1587428579&sr=8-3 Got questions around perlite and cement amounts used, so the whole bag of Perlite was 4 cubic foot, and I used a bit more than half. Cement was the regular 94lbs portland, and I used about half that bag.