I purchased an office chair mat for deep pile carpet and used it on a standard domestic carpet with a normal office chair (I weigh about 85 kg). It developed a crack and the suppliers (Office 365) are refunding me and say it often happens and they don't have a solution. They say a replacement may also crack and a chair mat for a hard surface placed on top of the original is also likely to crack.
Would something like a sheet of hardboard or ply (how thick?) be a solution?
Grateful for any suggestion as my chair is pretty immobile and in my 70s I really need it to shift around more easily.
Thanks
Cynthia