woodman2008

Dear Mr DIY Guy you need more experience and expertise before answering questions like this. It is widely accepted practice in the UK to use flexible adhesive to bond solid wood flooring to solid substrates like Concrete/screeds. the underlay that you used is useless when fixing solid wood flooring and it is against best practice to float a solid wood floor as this leads to failure in the bond and eventual separation of the flooring. This may of course take some time but in the end it will happen. it is a good idea to keep the ambient temerature stable but the use of underlay will nothelp this