Welcome to the Bunnings Workshop community @shann1825. It's great to have you join us and many thanks for your question.
Are these mats a product you have bought from Bunnings and if so, could you please post the link to the product? What type of surface are you laying them on and do you wish this to be a semi-permanent installation?
We look forward to hearing more details about your project and offering a solution to laying your matting.
We haven't got them yet. Just wanting to know how to do it first we was thinking lay sand down then the mats on top. I was told we have to buy 2 layers but that works out double the price just seeing if we could still do 1 layer for a kids area
Many thanks for the additional details. Products like the Swing Slide Climb Grey Rubber Pavers are used in conjunction with Swing Slide Climb 1 x 1m x 20mm Shock Pads. I've included an image of the number of shock pads required to help prevent injuries from certain heights. If there are heights which can be fallen from, I would strongly suggest you follow the manufacturer's instructions and the Australia standards shown below.
If there are no heights which can be fallen from, then you are free to install the mats as you wish, and an underlay of sand would be a suitable option.
Please let me know if you need further help or had questions.