I have a 4/12 hip roof, 14 years old, r40 blown insulation, ridge vent plus 4 square vents. styrofoam vents between each trussto allow for air flow, continous venting in the soffit. Every year by December My ceiling lifts 3/4 of an inch, 6' on either side of the center support wall the length of the house. The contractor put drywall screws into the ceiling boards right to where ceiling meets the wall. What do you suggest would be the best way to remedy the situation?
Answer:
Its those last fasteners you speak of that is causing your rafter lift. The only way you'll get rid of it is to remove the ceiling fasteners within 16" of the walls.Cornice moldings tend not to completely cover the consequences of what is known as rafter lift – ceiling joists responding to varying amounts of moisture content and then impacting on the drywall joints where walls and ceilings meet. You can normally get a way from permitting that joint to open by not having ceiling drywall fasteners nearer than 12 to 16 inches from the walls. That way, when the ceiling joist lifts or disfigures in any direction, ceiling drywall stays where it is because it will bend enough to not tear the tape.
Courtesy of Ren Molnar, Construction Consultant at HomeFocus.com. I can also be reached at (613) 748-3003 and Home Focus phone-in is broadcast live 8 to 10 A.M. (Ottawa, Ont. time) on Saturdays on www.cfra.com.
