Loose vermiculite fills the intended insulation space but does not independently form a rigid oven base. If it is to be near its bottom, first determine what bears the chamber's weight and encloses the granulate. Filling the void and supporting the floor are two different tasks.
Draw the space before purchasing a bag
Vitcas Vermiculite Loose Fill is a lightweight granular insulation with a declared resistance up to 1100°C. This format is used in suitable enclosed cavities, including compatible outdoor oven assemblies. However, it does not provide any floor panel with confirmed load-bearing capacity.
Mark the bottom closure, sides, top layer, and all passages. The granulate should not fall out during installation or find its way into the working chamber. If the project requires rigid insulation, consider the properly supported ceramic fibre board rather than substituting a loose-fill layer without checking the altered design.
Calculate the volume of the actual cavity
Calculate volume from the cavity area and depth, then subtract the space occupied by internal components. For example, one square metre of a cavity five centimetres high has fifty litres of volume. This is an example of the calculation, not a recommended insulation thickness for every oven.
Check the method of filling as well as any project requirements regarding settlement. Do not compact the material simply to fit a larger quantity. Record the working volume in the summary and separately the justified allowance.
Protect the granulate in the finished arrangement
The casing joints should limit water ingress according to the construction detail. Simply pouring dry material in April does not ensure dry conditions during later rainfall. Before closing, inspect the base, corners, and terminations at the entrance.
Keep a photo of the void and a description of the materials containing and protecting the insulation. During repair, this will help assess whether the issue concerns the loose fill, its covering, or the support of the part of the oven located above it.