Securing the oven base to the table

[Vivi88]

I have finished the perlite/cement oven floor, now to place it onto the cement top table. A question though, is it enough to simply put it onto the table and have it secured in placed under the weight of the oven and bricks? Or should I look to put some mortar or adhesive between the perlite floor and the hebel panels?

I've seen some people put sand between the table and perlite floor, but I feel this will cause the oven floor to sink down inconsistently once the actual weight of the oven is put onto the floor.