Spa Tub Install
 

I'm installing a Spa tub in an alcove. The tub (an American Standard Cadet Spa) has four feet that you level with shims. I have to put Leveling Stringers on that should contact the tub but not support any weight. I shimmed the four feet with Cedar shims and my question is how much will the tub settle down when it is filled with water (around 800 lbs)? Should I place the Leveling Stringers tight to the tub or not? Is there a different type of shim I should use?
Thank You for any guidance you can give me.

Yes use stringers

Thanks but maybe a little more info...
 

My question was not should I use stringers, my question was and is will the cedar shims compress with the weight of the tub? Should I leave a gap between the stringers and tub to compensate for the cedar shims compressing? Or place the stringers tight to the tub?

Cedar will compress, cedar is soft, set stringers tight to tub, we usally support the bottom with mortor mix.