This is a short description of my barrel vault build that I have done here in Central Portugal. The final internal size is a 1m squared floor with a arch height of 50cm. I hope you enjoy and get some ideas from it. I wish to thank ukwoodfiredovenforum for their advice and support. • 1: First I dug out a hole in the flower bed, on top of the stone wall, where the oven was to be built • 2: Set up a form to pour in the concrete base • 3: Pour the concrete base, which was about 5-6 inches deep • 4: On top of the base I cast 4-5 inches of LECA (light weight expanded clay balls) mixed with cement to hold it's form • 5: Then I cast a 2-3 inch heat retaining base, to add to the thermal mass, using calcium aluminate cement with large grain sand, as a flat base for the hearth bricks to sit on • 6-8: I then dry laid the hearth bricks on a dry bed of fine sand and clay mixture, with th...