Raising ceiling joists

[kp33]

Hello I just purchased a home and decided I wanted to see if anyone has ever raised a low ceiling height? I have a 7'4" ceiling that I would like to raise 8" to the More normal 8' ceiling height. This is a Gable roof 5/12 pitch Unfinished attic space above with 2x6 rafters spaced at 24oc. The ceiling I want to raise is a living room kitchen combo. 20x24, and the master bedroom at the end of hallway 24x16. I have got a few ideas about how others cut the existing ceiling joist and moved them up one at a time leaving the end for part of a box to form a tray ceiling. Has anyone done something like that before?
I am worried about my walls being pushed out by lateral thrust so the end result will probable being have an engineer look over this.

 

[guyod]

i was tempted to do something like but my roof was shoot so i ended up riping the roof off and raising the walls... not something i would suggest..

 

[Pinocchio]

You don't necessarily need engineering, although it is a good idea nevertheless.

Your local code office or knowledgeable framing contractor can also assist with sizing the new joists and rafters and spans.

Here's your problem:

When ceiling joists are fastened directly on top of bearing wall plates to resist the outward thrust from roof loads and fastened along side the rafters at that location, they are in the best poisiton to create a stable roof assembly.

Once one moves ceiling joists vertically above the bearing walls...the design not only reduces the ability of the rafters themsleves to resist those loads and keep the bearing walls from spreading....the design also reduces the ability of the rafters to resist loads placed upon them from things like snow and wind.

The result is, the higher you raise the joists above the top plate of the walls, the weaker the rafters become, to point that, depending on how high the joists are raised, the rafters themselves may also need to be replaced or increased in size or spacing to accomodate the loads.

Bottom line is, a design professional or code offical will usually need to assess the loads by your proposed design to see if it will work before you do anything.

 

[kp33]

Thanks pinoccho for your reply. Have u seen this done before, raising the rafter tie up alittle to gain ceiling height and boxing in your angle to form a tray ceiling?

 

[Pinocchio]

Yes, I have seen it done before and have done it.

You just need to make sure you are not weakening the overall structure of the roof assembly in raising the joists.

 

[dufunnel]

Hey kp, did you ever get this solved? How did you do it? I'm in a similar situation and looking for some information.

 

[ncatal]

I have the same situation can a do something like what a drew in this sketch?