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[zc15]

deleted

 

[inphx]

If DIY is an option a reach forklift rented @ 2 to $300 a day leaves dough for some extra hands.

 

[Walkers]

You are wanting to put a beam at the ridge and delete your collar ties? You would likely need a post at both ends, are there garage doors in the way?

 

[sky jumper]

this is how I did it. the forklift rental was something like $1500/week. setting the beam only took 30 minutes, but I didn't have a roof in the way, and my gable walls were designed to carry the load. I think you are much better off just raising the ties to get the height you need. trying to restructure the entire roof and add load bearing columns after the fact is going to be a nasty job. $25k maybe more. you'd probably need a 4ply 18" LVL at least.

 

[PoorUB]

Another problem I see doing that is you will need to beef up the end way to support the LVL, most likely a post to the floor of the garage, which incidentally is not designed to carry all that weight at one point, so now you cut out the slab in that spot and pour a footing for each end.

 

[Showkey]

Confused …….ridge board has no structural function , it’s location to nail the rafters, trusses often use no ridge board.

As mentioned Ridge beam needs posts at both ends……..that’s where term post and beam come from.

 

[PoorUB]

Confused …….ridge board has no structural function , it’s location to nail the rafters, trusses often use no ridge board.

As mentioned Ridge beam needs posts at both ends……..that’s where term post and beam come from.

With a ridge beam like the OP is asking about it will hold roughly half the roof load as he wants to remove all the truss structure and have an open ceiling. Without collar ties the ridge beam carries the load. The function of collar ties it to pull the walls together. No collar ties and no ridge beam the roof framing will push the walls apart and the whole works come crashing down. The ridge beam takes part of the load that would normally be held by the walls with a truss rafter system.

 

[billconner]

When you raise the rafter ties, the capacity of the rafter is reduced. There's a table in the building code but raising to the max - 1/3 - the span rating of the rafter is reduced about a 1/3.

 

[zc15]

deleted

 

[59bones]

Leave the ridge in place and rip the bottom if it extends down below the underside of the rafters. Your ridge beam can be tucked up tight to the underside of your rafters. Use some strap ties to connect the rafters to the new ridge. You will need posts at each end of the new ridge beam. At 24' wide and assuming half of the roof load is on the new beam, you will have about 600 pounds per lineal foot on that beam (SE Michigan with 30/35 pound snow load). 600 x 15' = 9,000 pound point load at each end. Probably use a psl column on the end with no door. Will definitely need to review your garage door header size because a 9,000 point load in the middle of a 16'/18' span will require more than a couple of 2x12s.

 

[firebirdparts]

The garage door is bad, but nevertheless, I don't think anybody will quote on installing this until you develop a lot more detail. Price is not the problem. Actual labor and materials to do it would be modest, I think.

Super easy if you had two garage doors, though.

 

[dcg9381]

This one is a tough one to SWAG, as it's all about local labor and how much construction pressure is in your area. The guys that can do stuff like this (around here) are very busy framing new houses and ask a substantial premium to get them to do "small jobs".

I agree with others, having a detailed structural drawing of what you want will likely be a big help. And offering the right equipment may make the job more "accessible" to more contractors - IE - one of those "sky" lifts...

 

[billconner]

It seems you'll end up installing a new beam - lvl probably - to support overhead door end of ridge beam. I suppose you could raise it a little if it's supported on columns in line with edges of garage door.

I don't know anything about your garage, but it could cost less to jack it up the additional clearance you want and build a block or other wall. I'm planning on using block for bottom 40" of 28 x 32 and it's less than $200 per 8" course of block. I'm so diying with dry lay and surface bonding the block.

Tough problem.

 

[theoldwizard1]

But I got thinking about just scrapping that idea, and quoting out installing a 30' LVL ridge beam.

A true ridge BEAM requires a post that runs down to the foundation to carry the load.

I've been looking for ways to increase my ceiling height in my detached 24x30 gable end garage. The cheap option is to remove my existing rafter ties, cut them down to size with a miter saw and reinstall 1/3 the way up the rafter height. This would net 24" which would work for my needs.

If the horizontal boards are at the top of the walls, they are called joists not ties. How far a part are they spaced and how wide are the rafters ? 2x6 @ 16" O.C. would be good. So would 2x8 @ 24" O.C.

If you are going to go this way, start in the center. Use a come-a-long attached to the top plate on each side. Tension until the stud below is truly vertical and then give it a couple more clicks. Now cut out the joist, position it where yo want and attach it to the rafter. Don't skimp on the nails/screws !