Originally Posted by ErikvanD
I will keep an eye on the cracks and in the mean time just enjoy playing the bass
That's a very sensible plan.
What's your weather been like? If its really 70% RH inside your house, you should probably be using a dehumidifier.
What temperature do you keep the house at?
I just looked up the monthly forecast for Amsterdam and its almost exactly like our weather here in Crescent Beach! The dehumidifier runs quite a bit when its ~50*F. outside and wet but slows down considerably when its in the low 40s outside and the heat is on more. Downstairs were the basses hang out its 62*F at 42% RH at the moment - damn near perfect.