Question on ceiling joist length and strength
bk1000
| Posted in General Discussion on
We have a garrison colonial home. The master bedroom is 17’3′ long X about 11′ wide. The 2X6 ceiling joists run the 17′ length. These long 2X6 joists are caught about halfway by a beam above them in the attic. That beam runs the 11′ width of the room, from one exterior wall to an interior partition wall. The joists are then nailed to the beam by some boards that come down from the beam.
See picture
My issue — we want to join this bedroom with the adjacent room by removing the partition wall, which would remove support for this “above the joists” beam. Will this create issues?
I’m assuming that beam is there to keep the ceiling joists from deflecting, as they aren’t able to make that 17′ run at only 2X6.
Replies
yes it will creat an issue. you are correct, that beam does keep those ceiling joist from saggin. you will either need to put in a new beam (more than likely an lvl) to span your new room width or take down the ceiling and change the ceiling joist direction.
Just thought of another option? Drop a column where the beam lands on the (soon to be removed) partion wall? So, the wall gets removed, and only a column remains.
yeah if you dont mind a column in the new opened area.
bk
remember to solid block below the floor to foundation. If post and beam, engineer such that it can take the point load.
The original wall is offset from the wall in the floor below by about 4" to one side (the joists between the first and second floor run perpendicular to the walls)
Does replacing the wall with a single column in the same footprint as the original wall make a huge difference? Granted it becomes a point load, but it's close to the wall beneath, and it's only carrying a beam that prevent the ceiling joists from deflecting. It's attich storage with minimal load.
The other option is to replace the wall with a beam, but the issue there is one end of the beam would end up in the 2nd floor cantilever, which I can't imagine is a good place for a post to carry a beam.
Replace the load bearing wall with a beam. Either below or above the ceiling. Unless you are knowledgeable about such things, get an engineer to do it for you. And like Calvin said, make sure there is bearable path to the foundation etc.
Bearing point
IT is hard to tell where the end of that beam bears, but extending it may be an option(an engineer could give you). As far as a point load(an engineer would say), a post would only be as good as it's path. The sheer strength of the joists between the offset walls is probably not an issue. However, if the post were to land between two joists, the floor may not have enough strength in that span. Also an option I can't confirm from pictures is taking ceiling load up to the roof load by making a "truss" situation for every member. Yes, my time at Purdue was well spent, both days.
Sister the joists?
Another option would be to sister a larger joist along side the original 2x6 ceiling joists....2x10 or 2x12's? ...2x8 each side?....and eliminated the beam altogether..It's tough to manueuver something this long in a confined space. You may have enough shear strength and bearing in the existing 2x6's near the end, that the sistered joists would not have to be full lenght - since the goal of them is to minimize deflection. Would need to run it by an engineer familiar with light frame construction.