Rasing ceiling height in half the shop

[k&l_performance]

Hi everyone new to group be been reading a lot of post and tread on rasing ceiling height so here’s my question. I have a 32x 48 shop with 10’ ceilings I’m wanting to put a 2 post hoist in so I wanna raise the ceiling height at least 3 feet. Had one option of raising half the shop ceiling 4 feet with building on top of exciting walls yes it pricy. Other options was nodding the rafters. I see a lot of ppl doin the whole width of the shop has anyone done just half the width. My shop I would need to mod 10 rafters and about 14feet keeping the hoist to one side. Has any one done it this way. Oh my rafter style is the “w” style I believe they call it
Thanks all for your time

 

[mike93lx]

Pictures will save a lot of time.

You'll want an engineer involved if modifying trusses or adding height. Adding wall height is tough as it creates a hinge in the wall that needs to be designed properly.

How much height you can get by modifying the trusses will depend on roof pitch

 

[billconner]

True rafters and rafter ties/ceiling joists OR trusses? Approaches to raising vary a lot depending on roof structure. Agree pictures would help.

 

[nickelTwin]

. Oh my rafter style is the “w” style I believe they call it
Thanks all for your time

It sounds like you have roof trusses. You should get an engineer or a truss designer to help you modify your existing trusses.

Is this getting city permits and inspected, if so they will require engineered drawing of modifying your trusses.

Consider this. If your roof collapsed in the future because of improperly designed and modified trusses, damaged your vehicle and tools or someone gets injured and you file a claim with your insurance and they determine the roof collapsed because of your modified trusses, they will probably fight your claim.

If you do have engineered drawings and inspections. You will most likely be paid.

Not knowing where you are, snow loads, high winds, etc.may need to be taken into consideration

Somethings to consider.

 

[k&l_performance]

The roof is a 4/12 pitch I’ll try and get pics the ceiling is sheeted so plan to pull a section down this weekend

 

[nickelTwin]

I

 

[mike93lx]

4/12 means your peak is only a bit over 5' over the walls. Getting 4' isn't happening.

You could put in a scissor truss with a 2/12 interior pitch, and maintain the 4/12 outside pitch. That would get you about 2.5ft at the center

 

[nickelTwin]

You posted pictures at the same time I posted my last comment on rafters

 

[k&l_performance]

4/12 means your peak is only a bit over 5' over the walls. Getting 4' isn't happening.

You could put in a scissor truss with a 2/12 interior pitch, and maintain the 4/12 outside pitch. That would get you about 2.5ft at the center

Yea sorry it’s not 4/12 that was my other shed it’s definitely high peak from the ceiling height there is more than enough room to go up min 4ft for sure

 

[mike93lx]

Yea sorry it’s not 4/12 that was my other shed it’s definitely high peak from the ceiling height there is more than enough room to go up min 4ft for sure

Scissor trusses usually use half the outside pitch for the inside. If it's a 6/12, that's 8' from wall to peak, 3/12 inside would get you 4'. But keep in mind that's only in the center

 

[billconner]

Here's what I see as options:
1. Raise half the garage. Rather than building atop wall and raising trusses and the problems of 14' studs and stiffening, lift the whole thing (half the garage walls and all) and build a 4' block wall under it.
2. Tear off half of roof trusses and all roofing and rebuild roof with new scissor trusses like 12:12, 6:12 inside, adds 8' at peak.
3. Replace trusses with rafters, a ridge beam, and add a column (post) to support ridge beam at center. If heavy snow load, might have to be TJI rafters but hopefully 2x12 max.

I'd probably pick no. 3 because it should be least material cost and I could do myself and not require (registered) engineering, and doesn't leave garage open to elements. Unlike 1 and 2, no zoning review - same envelope outside.

 

[mike93lx]

If you tear the roof off, raised heel scissor trusses may make adding height easier that adding a wall on top of the existing wall