If you are building an oven for personal (home) use then you should use bricks. Brick ovens are low maintenance and preferable for home use. Clay ovens require more care during construction and may start peeling or cracking if not done right. Brick ovens use 3/4th of the heat from the fuel/fire, leaving out only 1/4th of the heat, which makes them fuel efficient as well. The bricks absorb the heat very well, have a very good thermal conductivity and heat withstanding properties, which makes them ideal for extended use.
Mortar is needed at almost every step in the building of a pizza oven. There are two types of mortars and neither should be substituted for another.
When flat fire brick joints are difficult or impossible, refractory mortar is used. Its maximum application should be no more than about 6mm. It shouldn't be used to fill holes or empty spaces in the oven. It is only suitable for external use on the oven.
Refractory Mortar can be prepared by mixing Sand, Calcium Aluminate Cement and Fire clay in the ratio 10 : 3 : 1.5:
Note: Use the grey Portland cement, not white.
This is the mortar that you will use to lay the bricks of your pizza oven. The mortar is for use with general building bricks, not refactory fire bricks. It is very easy to prepare. To make General Purpose Building Mortar, you need:
To make this building mortar, you will need the above components in this ratio 6 : 1 : 1.
Mortar can also be made with just sand and cement without the lime in the ratio 4 : 1. Lime allows for mortar to be easier to handle and increases the drying period giving you three times as much time to work with.
To prepare the mortar, first of all you will need to mix all the components properly (do not use water, only mix dry component.) Once you have finely mixed them, add a little bit of water whilst mixing. Continue adding water at regular intervals, while mixing, until it forms a paste as thick as peanut butter.