Need additional Ceiling Clearance for Lift

[kbuhagiar]

Hello Folks,

I would like to install a 4-post lift in the single bay of my three-car garage.
The existing ceiling height is approximately 9'8". I would like to modify the ceiling directly above the lift location in order to get some additional lift height. My thought was, by strengthening and reinforcing the adjacent rafters, to somehow 'box in' or remove altogether the two rafter ties directly above the bay.

I have seen other examples of similar garage ceiling modification (mostly here on GJ) and based on what I have seen I was under the impression that it would be a relatively straightforward modification, if done thoughtfully and carefully. However I sent these same pictures to a local structural engineer, and he pretty much blew me off, saying it would be too costly and expensive (I think he said I'd need a ridge beam).

I'm discouraged, to say the least. Based on the pictures provided, does anyone see anything in particular in the ceiling that would create any unusual difficulties or expense? I live in California, no snow load on the roof to worry about.

Thanks in advance.

 

[astroracer]

This is what I did for my hoist area.
Looking toward the garage door you can see I plated the entire truss on either side of the bay I was opening up with OSB.

Added collar ties to the three rafters I was cutting out. After the middle of the truss was removed I plated the entire top of the opening with OSB. You can also see the verticles I added to the two end trusses to give the added OSB something to attach to and give it some robustness.

I also added 16" engineered floor joists at both ends of the opening.

These go thru three sets of trusses on both sides of the new opening.
In this pic you can see where the three trusses were cut of at the engineered floor joist.

The cut off trusses were tied into the new structure with joist hangers on the back side.
If you do something along these lines you should be okay.
Mark

 

[ms fowler]

When you need structural sheathing, remember that OSB has only the binder working to resist tension forces. While it often works, if kept dry and away from sunlight, it is not the best choice. Plywood is the sheathing to use in these situations.

 

[Ironcrow]

However I sent these same pictures to a local structural engineer, and he pretty much blew me off, saying it would be too costly and expensive (I think he said I'd need a ridge beam).

I'm discouraged, to say the least. Based on the pictures provided, does anyone see anything in particular in the ceiling that would create any unusual difficulties or expense? I live in California, no snow load on the roof to worry about.

Thanks in advance.

For this job, you don't want an engineer. Hire an experienced framer and tell him what you want to end up with. Looks like you sister the adjacent joists, remove the two in the middle, add some purloins between sistered joists, and sheath in plywood. High lift the garage door. Install lift.

 

[JohnnieMo]

Search out "Woodys Works Garage". He replaced his trusses with a ridge beam. Turned out awesome. It's a smaller job than you'd think.

I had to lift my entire garage just to get that 9'8" you've already got!


Sent from my BlackBerry Priv

 

[woody6904]

I see no problems with it as long as its done properly. We had to do this exact thing 10 years ago to the rafters in the barn so the new combine would fit. Have never had a problem.

 

[lakeroadster]

For this job, you don't want an engineer. Hire an experienced framer and tell him what you want to end up with.

Horrible advice, simply horrible.

If you are modifying trusses, and don't involve an engineer & your local zoning (if applicable), and the truss fails, guess who will be paying for all the damages?

Hint: It won't be your insurance company.

If you're ok with that and possibly injuring the one's you love and your stuff... then shine on you crazy diamond.

 

[dave*99]

OP, have you considered a ridge beam? The engineering is simple. You can get the info right from the beam manufacturers website. Then you could remove all the collar ties and Sheetrock the ceiling. And then you could..... Sorry I get carried away some times.

 

[Ironcrow]

Horrible advice, simply horrible.

If you are modifying trusses, and don't involve an engineer & your local zoning (if applicable), and the truss fails, guess who will be paying for all the damages?

Hint: It won't be your insurance company.

If you're ok with that and possibly injuring the one's you love and your stuff... then shine on you crazy diamond.

If one can not accomplish this simple job then they shouldn't be allowed near sharp objects and power tools.

 

[kerr]

LOL , Agreed .

 

[lakeroadster]

Hello Folks,

I would like to install a 4-post lift in the single bay of my three-car garage.
The existing ceiling height is approximately 9'8". I would like to modify the ceiling directly above the lift location in order to get some additional lift height. My thought was, by strengthening and reinforcing the adjacent rafters, to somehow 'box in' or remove altogether the two rafter ties directly above the bay.

I have seen other examples of similar garage ceiling modification (mostly here on GJ) and based on what I have seen I was under the impression that it would be a relatively straightforward modification, if done thoughtfully and carefully. However I sent these same pictures to a local structural engineer, and he pretty much blew me off, saying it would be too costly and expensive (I think he said I'd need a ridge beam).

I'm discouraged, to say the least. Based on the pictures provided, does anyone see anything in particular in the ceiling that would create any unusual difficulties or expense? I live in California, no snow load on the roof to worry about.

Thanks in advance.

The ridge beam concept that the Engineer eluded to is a good one. It would entail using a king post style truss that spans the garage (front to back), one on each side of your new lift. A ridge beam would span these. Then the top of your rafters would be supported by the ridge beam. This may require additional wall studs at the location of the king post trusses.

This would be retrofittable to your garage.

Don't get discouraged by the one Engineer rejecting your idea. Find another engineer, hopefully a motor-head / gear-head type that will work with you.

The issue with cutting the lower chord (or lower rafter tie / ceiling joist), as astroracer did above, is the downward load of the roof wants to push the walls of the building outward.

The support provided by a ridge beam holds everything in place.

 

[redmondjp]

^ What lakeroadster said above. You don't need a ridge beam over the entire space, just spanning the area directly above the lift. Then all you have to do is to engineer the additional support needed at the ends of the new ridge beam. For that width, it's not that hard to do as stated above.

 

[kbuhagiar]

Thanks to all the responders for the suggestions and support.
I realize that the first engineer was not really interested in working with me. I am now looking for someone local who has done this sort of modification before.

 

[JohnnieMo]

Look into the suppliers of LVL beams (ie. Truss manufacturers). I know for Denwood since he was buying the ridge beam they did the engineering for him. I can't recall for sure but I think it was included.

Truss manufacturers usually throw in the engineering for free since it's all automated anyways.