Our house was built in 1949...old..and it still has nearly all of its original tongue and groove flooring, and roof! All is in great condition and we've lived here for 12 years. These days the tongue and groove serves as the subfloor with padding on top and until recently carpet. In March we replaced carpet with laminate hard wood. We saw then subfloor was still immaculate, and until 6 weeks ago the new flooring was doing great. But now suddenly there is a hump under one area about 4 ft long and about the size of 1 or 2 tongue and groove boards. Husband has gone under the house, its in the living room so no water, and no dampness underneath and it also seems its a gradual small bow because nothing was obvious from underneath. so we thought it was laminate peaking from edging space so we popped trim up and made better gap around that corner of the room..didnt help, but I know peaking doesnt always go away immediately. Started pulling up bpards last night and got to the bowed spot and its defanitely the subfloor, gradual as it is its making all the difference in the laminate! Not sure how besides just being old, why the floor would suddenly do this, and what is the best way to repair the small area of subfloor without completely replacing it?? TIA!!