My whirlpool tub is not quite horizontal - is that a problem?
If the foundation of your whirlpool tub is only slightly inclined, then this does not impair the whirlpool tubs's performance or its construction. The installation surface, however, should not have a slope, depression or bumps. Most terraces or backyards are built so that they slope away from the house, so water can flow away from the house. The inclination should not exceed 1.27 cm over a distance of 2.44 m. No levelling pieces/stones or shims should be used to level the whirlpool tub as they can cause tension in the tub and cause damage to it.