The siding on the back of our new house got all wavey within a few months. It is a 2 story modular and is wonderful in almost every way. The builder has been good and sent a person to inspect and then a crew to replace some of the sheathing. They said the OSB was still hot when installed and so it lost shape and bulged between the studs. Now indeed it was bulged between the studs when they pulled the siding and plastic off. Everything was bone dry underneath. No water marks etc. It happened again in the repaired area. Crew came out and checked. same thing, bulged between studs and bone dry. I asked for an explanation of this "hot" OSB. the last foreman here said the glue in OSB takes a while to actually set/cure. The OSB is not actually warm, but still so fresh that the glue has not fully set/cured. He says it can take a week or two to fully set. If the OSB is put up too soon, it sags due to gravity, or bulges due to heat from the sun. It had definitely bulged and it was definitely dry. I overheard him talking on the phone with the builder about the problem and the foreman said yeah hot OSB again. He told me the builder orders OSB by the railroad car and they had the same problem a few years ago and had to re-sheath several of their homes. I have been to the builders business and they do order by the train load. There is a siding next to their warehouse. I saw them unloading skids of 2x's from several flat cars.
Is there really such a thing as hot OSB or am I being spun?