I have been looking round for wooden flooring and was set on the click type as this is what I have put down before. However, all the flooring I like seems to be tongue and groove so I have decided to go this route and take a bit longer to lay it. It will be laid on a solid floor with underlay and will be glued at the edges. Is there any problem with laying a glued up floor on thickish underlay that will have some degree of flex. Will the wooden floor have enough flex for the underlay or is this not an issue?