For a standard un insulated floor, the floor bearers are designed to run left to right across the building and at intervals of approximately 480-500mm centre distances from front to back. These bearers are supplied as stated in the cabin parts list. This method has open sides.
For the insulated floor there are some additional materials supplied, extra floor bearers and insulation boards.
It is necessary to create an enclosed void for the insulation material. The additional materials supplied will provide the floor bearers that run along the length of the building under the side walls. For them to fit, it is necessary to reduce the length of the original intermediate bearers by 116mm. Thus original bearer – 116mm ÷ 2 x side bearers = width of cabin. The additional material will need to be cut to the appropriate length of the building.
Floor insulation shown underneath the floorboards
The insulation is 50mm thick foil faced rigid urethane boards. This needs to be cut into convenient strips to fit between all the floor bearers. The board may be laid in any direction and pieces may be butted together.
Generally it is good practice, although not essential, to lay the insulation on a plastic membrane (not supplied) and to sit the boards on thin packers to provide a small air gap beneath the insulation boards (if space allows within the height of the bearer).