My parents are visiting relatives until the end of January. Meanwhile, for several years one area of the bathroom has been subject to tub-splash, such that the subfloor next to the tub under the linoleum feels 'spongy' when you walk on it. The house is a one-story house with no basement, only a crawl-space beneath. Any ideas what kind of repair might be required? Has anyone repaired the floor of a 1970's era tract house before? I am considering whether this might be a project that I can do for them as a surprise for them when they return home; it has been a worsening problem for years. Also they've been wanting to re-do that bathroom anyway and this would let me put in a faux-travertine tile that I think will give them the look they want without the maintenance requirements of real stone--to upgrade instead of the 36 year old linoleum currently there. They keep talking about it and never actually do it... Since the spongyness extends right up to the tub edge, do you think repairing this would require removing the tub? Also, what about the adjacent wall, as the spongyness meets the foot of the wall (though the wall isn't spongy).