Records not stored vertically for decades

Recordguardian, I was wondering whether there was any scientific basis for the 70 degree F cutoff point. That seems low , plus I would think humidity plus temperature together are the determinants. Therefore the temp cutoff would vary with ambient moisture. Furthermore while it seems inescapable logic to say that storage at an angle promotes warping, one also notices (during my own 50 years) that sometimes warps appear for no logical reason, even in LPs stored vertically in tight rows, and even free of charge in brand new LPs.

Where do you get your “rules of warping”?

Always a good idea to clean your LPs, but I see no reason why horizontal storage would make the LPs any more or less in need of a cleaning.  I disagree that even the bottom-most LPs in the pile would have had dirt driven into the grooves to any greater degree than if the LPs had been stored vertically, because the playing surface per se is not supporting most of the weight exerted downward by the stack.  That force will be mostly resisted by the raised lip around the circumference of each LP and to some degree possibly by the label.  The greater possibility for damage is that the topmost LPs might have developed some warps.  But that you can discover for yourself by simply looking; you don't need to be able to play an LP to determine if it is warped.  Someone else already said as much.

But Raul’s pint is valid, especially since we are not sure we have the full story(conditions of storage being the most important). Why not play a few LPs from the bottom of the stack and a few off the top.? Then let us know your results.