Replacing Trusses to Gain Ceiling Height?

[Gieb]

Hi everyone,

I have a detached 24' x 26' unfinished garage in Minneapolis, MN. It only has 8' ceilings, and I'd like to increase that height as much as I can to accommodate my 4 post lift. I've searched the forum, and most folks recommend hiring a structural engineer to create plans for modifying the existing truss structure.

Given that my garage is completely unfinished, I'm wondering if it would be simpler and less expensive to replace the existing pre-fab trusses with new higher ceiling pre-fab trusses. Is there any reason I couldn't add new trusses next to the existing ones, and then simply remove the old ones? Pre-fab trusses appear to be ~$100 each, so that's only $1200 to replace all 12. No engineering plans needed.

A few photos of the existing structure are attached.

Thoughts?

 

[mike93lx]

Gable trusses are different.

Are you pulling a permit? If so, engineering might be needed anyway.

Keeping the existing wall height, you can gain some celing height, but it will be mostly in the middle

 

[lakeroadster]

Overhead door is at gable end, correct?

Are you planning to put the lift centered in the garage or off to one side? If off to the side, how much of center?

What is the pitch of the existing roof?

What vehicles are your planning to lift?

What 4 post lift do you have?

Are you expecting the lift to go full height?

 

[LX-Markham]

Almost identical to my 19x20 detached garage.

I left the truss top chords in place, sistered rafters to them, and used a structural steel frame around the perimeter of the top plate to handle the horizontal thrust from the rafters.

You will definitely need a structural engineer.

 

[mike93lx]

Almost identical to my 19x20 detached garage.

I left the truss top chords in place, sistered rafters to them, and used a structural steel frame around the perimeter of the top plate to handle the horizontal thrust from the rafters.

You will definitely need a structural engineer.

Really interesting solution!

 

[nh_yota]

I assume you went with the roll up door so it wouldn't block the ceiling when open.

 

[Keith_MN]

I would think that lifting a complete new truss in next to the existing one would be difficult since the tails need to sit on top of the existing wall. Maybe you could take one old one out at a time and get enough room to angle the new one in place? Some of the shingle nails may have to be trimmed to get the new truss to sit up next to the roof decking.

 

[JohnnieMo]

Unless you plan on removing the entire roof I would think installing a ridge beam is your best bet. Woodys Works Garage is a thread to review. You can still get engineered plans from the beam manufacturer.

In my case I lifted the entire garage by 2 feet. It’s very cost effective as well. I have a video on it.

 

[Orionrising]

what age and condition are the shingles in? if it needs a roof anyway, simplest could be to remove the roof and trusses and frame conventionally with a ridge beam.

 

[James-W]

I have mixed feelings about it. Some people raise the building about feet. Others rip off the roof, add on to the walls, then put on a new roof using the old trusses. Each way has merit to it, but I am not sure what the less expensive way to do it would be. I think you would have a very difficult time trying to install different trusses without taking off the roof first.

 

[JohnnieMo]

Almost identical to my 19x20 detached garage.



I left the truss top chords in place, sistered rafters to them, and used a structural steel frame around the perimeter of the top plate to handle the horizontal thrust from the rafters.



You will definitely need a structural engineer.

What you did here is brilliant. I never thought of such an approach.

 

[lucky3]

Unless you plan on removing the entire roof I would think installing a ridge beam is your best bet. Woodys Works Garage is a thread to review. You can still get engineered plans from the beam manufacturer.

In my case I lifted the entire garage by 2 feet. It’s very cost effective as well. I have a video on it.

Do u have a link to the video. I'm thinking of raising mijne.

 

[bpjr]

Call a local truss company (that actually makes trusses) and ask them to do the calculations. This is really what a contracted "structural engineer", architect or contractor will do anyway. Talk the them before calling anyone else and see what they have to say.

 

[firebirdparts]

The wall stiffening approach is something we don't talk about much here, but I have that on the lift side of my shop as well. My stiffener is wood framed which it turns out is good for storage too.

With 8 foot walls, you really need a totally empty roof to get a lift in there. You need as much height as you can. A big ridge beam would also work about as well.

Generally in these height threads there are so many people talking about scissor trusses that everything else gets drowned out.

 

[Gieb]

I really appreciate all the responses so far. It looks like I have a lot of good options.

Responses to your questions and a few more details:

• I don’t have any specific height goals. I can just barely squeeze my Cayman and Miata on top of each other right now, and I’d like to have more leeway for different cars in the future and have more space while I’m working underneath them.
• I plan to insulate and finish the garage over the summer, so I want to “future proof” the height beforehand. Another 2 feet would be great. More than that would be icing on the cake.
• Using really rough measurements based on a photo, I think the pitch is 6:12. I’ll measure actual dimensions tonight to verify.
• My lift is a Direct Lift Pro Park 8S. I don’t need it to go full height - I just want to maximize my space. The left ramp is about 5 feet from the left side of the garage.
• The garage door is on the gable end.
• The garage was built in 2013, so everything including the roof is in near new condition.
• Attached are a couple more pics for reference.

So far, it looks like the options are as follows:

• Swapping my trusses for scissor trusses. This is what I considered in my original post, but it sounds like it would probably be challenging to do without removing the roof.
• Modifying trusses. This seems like a reasonable option, but I don’t know how much height I could gain, and I would be placing a lot of trust in the structural engineer to come up with the most ideal design.
• Raise the entire roof and add more height to the garage wall. Nobody has mentioned this on the forum yet, but I just got off the phone with a structural engineer, and he mentioned this might be the best / most cost effective option. Any thoughts?
• Raise the entire garage and add a cinder block footing. This seems reasonable, but it would require new entry and garage doors.
• Completely remove the trusses in favor of a ridge beam. This would maximize my height and provide a nice open feeling, but I think I would need to reinforce the gables.
• Completely remove the trusses in favor of something like LX-Markham’s design. I’m not sure what to call this, but it seems like a great solution. This seems equally as good as a ridge beam.

Does anyone have any thoughts on the cost of any of these? Are any more DIY friendly (assuming I have engineered plans) than others?
Thanks!

 

[JohnnieMo]

Do u have a link to the video. I'm thinking of raising mijne.

Here it is:

Read the comments as well. There were a lot of questions about lifting the roof vs lifting the base. In the end I think there are reasons to do either.

There is also a thread I started on lifting the garage.
https://www.garagejournal.com/forum/showthread.php?t=308011

I really appreciate all the responses so far. It looks like I have a lot of good options.

So far, it looks like the options are as follows:

• 
  ....
• Raise the entire roof and add more height to the garage wall. Nobody has mentioned this on the forum yet, but I just got off the phone with a structural engineer, and he mentioned this might be the best / most cost effective option. Any thoughts?
• Raise the entire garage and add a cinder block footing. This seems reasonable, but it would require new entry and garage doors.
  

Does anyone have any thoughts on the cost of any of these? Are any more DIY friendly (assuming I have engineered plans) than others?
Thanks!

Since you have an unfinished garage I think the cost to either lift the garage or lift the roof would be fairly economical. I suggested in my video that it was $500. That was about $200 for custom beams, then supporting lumber and 4 bottle jacks. I used a crib wall or a pony wall, although that necessitates sistering the studs after the fact, and that can be a nuisance.

I had a theory at the time that if I already owned my 4 post lift (as you do) I could just lift off the roof. This would involve cutting any ties to the walls, and removing or cutting any electrical. Then you could lift the roof with the 4 poster and graft in a couple extra feet. I think the best way would be to build mini triangular trusses and use them to join the top of the wall to the existing roof. It would take up some space along the walls, but would make the entire thing a lot stronger and would eliminate any of the sheer load.

 

[lakeroadster]

With the lift off to the side, and a gable entry door, about your only option is to raise the building so you have a higher side wall.

 

[Falcon67]

If I was starting with your same raw material - unfinished type "box" - I'd raise the roof. I've lifted a 22x16 so a 24x26 would not be much of a stretch. Mechanically anyway. The only issue I see would be removing the siding and later getting it back in shape and consistent.

 

[NUTTSGT]

You need a bigger garage, add another bay with taller ceilings.

 

[stingry]

[QUOTE
[*]Modifying trusses. This seems like a reasonable option, but I don’t know how much height I could gain, and I would be placing a lot of trust in the structural engineer to come up with the most ideal design.[/QUOTE]


To me, this seems like the best option. Since you really only need additional space above the lift to make the lift more functional, I would modify the trusses to utilize all that space above the lift. This can be done in several ways. I will not get into the specifics but a structural engineer or even a very good carpenter could do it, depending on your comfort level and local code requirements. There are several members of this forum who have done this. Try a forum search.