I'm a newbie to the forum in search of answers. I have a house that was built in the 50's. It a solid built house with 12" pine tongue and groove planks on the ceiling and walls of the living room and kitchen. I've been renovating the house, trying to update it over the past 4 years. In the last 2 years, I've noticed that the ceiling in the living room is developing a sag. The sag is closer to the middle of the house, closer to a load bearing wall. I've noticed that it's beginning to worsen. I can calso see that a seam between the tougue a groove appears to be getting wider. In the attic I have trusses. It appears to have enough bracing above the living room area. I have not removed any load bearing walls. I did have to jack up the floor about 2" on the opposite side of the house. Any suggestions on how to raise and support this problem? Any suggestions are appreciated.