I have a 20x50 area that is totally open half great room and half kitchen area that is slab on-grade. We are wanting to put 5-inch engineered hardwood throughout that space and I am looking at leveling the slab to be able to do floating with glued T&G. I have read that most floating floor installations will have an issue with going that long, but I am wondering if there is any way to reduce my risk of buckling because my wife doesn't like the look of T-moulding. The kitchen area is huge with a C-shaped set of base cabinets with a floating island in the middle if that makes a different. The other half is totally open with a stone fireplace in the middle.

You just need a little more expansion space, undercut sheetrock, add wide base and maybe shoe. The stone fireplace can be undercut with the right saw.

Thanks for the reply. Around the kitchen cabinets and island, should I do 3/4 inch or is 1/2 enough?