We have recently come to a halt with our building due to our hardwood floorboards cupping and swelling in several places.(Boards were acclimatized for several months before installation) They were laid by a so called professional installer, who sealed the concrete first then laid the boards, sanded and applied only one coat of lacquer.
Within a month we noticed boards cupping and swelling!! The installer has no idea of the cause and wanted more money to fix the boards, but not fix the cause of the problem. Since then we have given him the boot!! (unfortunately paid him majority of the money!! and heard nothing from him since!!)
My husband (handyman) replaced the popped up boards and sanded the entire area lightly at first waited another few months then sanded the entire area again. Now are faced with the moisture coming up through the joins as pictured.
Is there any solution? Our next step is an expensive inspector, but unfortunately money is an issue right now. If there's anybody out there that has had this problem or knows how to solve or point us in the right direction would be so helpful.
Beginning of problem.
Another pic, repair stage boards replaced and lightly sanded. Within a week of sanding Moisture coming up.