Garage 'ceiling height'

[Wood Grower]

Why did you even post here if you don't want to take the advice of those here who have experience and know-how? Do what you want you what you are going to do anyway we will not stop you but we won't validate your ideas just because you are too lazy to do it right.

It was stated early on this sort of thing is possible, however some people are trying to say don't bother because you don't know what your doing without knowing what I know. I can fabricate something that will be stronger than an engineer would make and stamp and the material costs will be lower than engineering costs. Engineers try to figure out the minimum material to do something safely. Engineers even doing this have failed greatly by building bridges that have collapsed. It is a serious job engineering, but if they say use a 2x6, I could put a 4x12 in place have more material use but a much stronger than engineered. This isn't a thread about how wrongly a job can be completed, it's a thread about is it possible to change from one system to another without taking everything down. Even it was suggested to buy prefab truss and build more on site that are identical to the fab unit, install then take off the old wood. So from at least 2 - 3 angles have been identified how to do this, but nobody said what sizes shapes to make to make it safe probably because they aren't engineers and identifying as an engineer falsely is a crime.

[iamtooler]

lI do not pretend to know the ''law'' but normal building repairs don't require permits under a certain value and I cannot imagine an engineer wanting to approve modification to a building for which there were never plans. Possibly a complete new roof structure but even then not knowing the wall specs and condition he would probably decline. Preengineered buildings only started in the late seventies on farms around here and still today my local lumber yard will

[Jerome]

With all due respect according to the Ontario Building code which has jurisdiction here and the Canadain Building code that is exactly what he has to do. All the advice he has gotten here is great but changing the structure as he wants to is illegal without an engineered drawing and the approval of the local building department. As a facilitator for the OBC and a longtime construction worker, I think I know what id be doing but, I would not attempt this without an engineer's approval and neither should anyone else.

[iamtooler]

Why did you even post here if you don't want to take the advice of those here who have experience and know-how? Do what you want you what you are going to do anyway we will not stop you but we won't validate your ideas just because you are too lazy to do it right.

With all due respect telling somebody to hire an engineer and bring in inspectors is the lazy answer. There is nothing difficult about what he wants to achieve and the value is not there to justify an engineer's study. For a couple of hundred dollars he can replace the ceiling joists with a superstructure that will be stronger than they were.

[Jerome]

Why did you even post here if you don't want to take the advice of those here who have experience and know-how? Do what you want you what you are going to do anyway we will not stop you but we won't validate your ideas just because you are too lazy to do it right.

[John Bartley]

I'm just going to post this as an observation and an idea of what "I" would do if this were my thread and garage. This is NOT an encouragement to do anything.

In this part of the country, "making do" has always been part of the psyche and because we have small populations spread out over large areas, the resources are sometimes limited, including building inspections etc. There has traditionally been an easing of requirements around here for buildings that are not habitations, including garages. Most of the garages around here are constructed using home brew trusses and rough cut, unstamped lumber. The trusses are assembled using plywood webs nailed to both sides of 2" x ?" parts, and that includes my own garage here, built several decades ago and still as solid as a rock.

The OP's garage is not trusses however, so ....

In the case under discussion in this thread, what I would likely do is cut a cross tie piece the same thickness as the rafters, bevel the ends to fit "under" the rafters and cut it to a length that allows it to be installed about 12" or 18" above the current ceiling joist. Then I would create plywood webs, large enough to span from the end of the rafter at the eave (or as far down as I could go), along the new cross tie about 18" to 24" (whatever looked appropriate) and up past the tie toward the ridge an equal length to the length below the tie. I would install verticals the same way in order to create a torsion box effect using the existing rafters, new cross ties and new verticals and use the ply webs to spread the load across the joints. Once that was done I would cut out the existing ceiling joists (cross ties) to make my new headroom.

Again, this is speculation, but it's what I personally would look at.

[Wood Grower]

I'm not sure if you're asking or telling us. I am absolutely sure if you use quarter inch mild steel plate using at least a dozen hot rolled rivets at every connection with all the roof trusses also made out of quarter-inch steel you will be fine if they're on 16 inch centres and they're more than 18 inches thick. If they are double gusseted at every connection with hot rolled rivets you will be fine. How big is the shed again? What is the dead load calculation for your area and what are your walls studs? 2 x 4 or 2 x 6 or 2 x 8? Is this a floating pad or does it have a structural footing?

My standalone garage is 23 x 23. The footing is 5 foot below grade and is 8 inches thick and 24 inches wide. From there I built up 8 inch wide centre block aboat 10-12 inches above the soil. I insulated the block wall on both sides with 1 inch of foam and then put a weeper tube around the footing that drops into the septic weeping system. The 1 inch of foam on the inside of the block wall got 6 inches of a gravel topped with a floating 6 inch concrete cement pad. The walls are all 2 x 6 construction with stick frame 2 x 6 on 16 inch centres roof trusses and joist. I personally engineered it all, but I took it through the local building department. The local building department charged me about $200 as it also had a 60 amp panel in it.

Yeah the whole build did cost me close to $30,000, Labour not included, but the city put it on as a registered certified outbuilding. I'm not sure if this is what you're looking for or not.

I have also lowered trusses by using Jack posts on every stud and a 12 high foot garage lowering the ceiling to 8 feet. This provided a loft. A city engineer gave approval for replacing the 6 inch joist with 12 inch joist with proper Jack support. The span was only 14 feet.

Reach out to your city engineer with a building permit and it will cost you almost nothing to get good advice. You pay city taxes for this. Why not take advantage.

My good old regular garage, the way I designed it could definitely I have a second floor. I would have to double or triple the 2 x 6 joists for living quarters and I might have to double or triple the studs. But, I would take this through my city engineer.

Not doing it through the city, in 10 years they could mandate nonconformance rip down. If you're trying to skate through the 10 years with engineering advice here. It will not float with the engineer in department of your city!

I'd rather see you make it safe and to engineering specs with your local building department on board, then doing it on the down low.

What's up? Are you scared to take out a building permit with city engineers? Are you afraid of property tax implications? I did not add water to the building. My property taxes or raised $200 a year for the building. I'm not crying. The building upped the property value by easy $100,000.

I have a legal non conforming building. I hate it but it has concrete walls with wood roof. It isn’t big at all. If it collapses I wouldn’t shed a tear because I hate it absolutely. It is on property line and on odd angle too small too close to the house. I don’t think there is anything positive I like about it. Even the overhead and man door are junk. As I stated before just buying time to use longer. But I might be tear down and have new one next year and speculation is kind f pointless f I go ahead that quick.

As for engineering screw the and their Covid hysteria. They completely closed down engineering for a while. It might be open now but it is more hassle than it s worth in my opinion. I’d rather just overkill it than deal with their drama. I don’t even think we have Covid but we have fear here....

[Matt Matt]

If I use 3/8 bolt grade 9 and make 2x6 oak board, I think it would be just fine. Even 1/2 or 5/8 bolt would be fine. The strength goes up significantly as diameter increases. Can probably be 3/8 x 4 bolts spaced 3 inches in line, and a plate over it, I'm pretty sure nothing would be unsafe about that. I could even make wood 3x6 or 2x12. Like I said wood isn't the issue. I'm pretty sure something could be sorted safely. The only thing is too big of bolts lowers the integrity of the wood so going with smaller fasteners seems better idea than large ones.

I'm not sure if you're asking or telling us. I am absolutely sure if you use quarter inch mild steel plate using at least a dozen hot rolled rivets at every connection with all the roof trusses also made out of quarter-inch steel you will be fine if they're on 16 inch centres and they're more than 18 inches thick. If they are double gusseted at every connection with hot rolled rivets you will be fine. How big is the shed again? What is the dead load calculation for your area and what are your walls studs? 2 x 4 or 2 x 6 or 2 x 8? Is this a floating pad or does it have a structural footing?

My standalone garage is 23 x 23. The footing is 5 foot below grade and is 8 inches thick and 24 inches wide. From there I built up 8 inch wide centre block aboat 10-12 inches above the soil. I insulated the block wall on both sides with 1 inch of foam and then put a weeper tube around the footing that drops into the septic weeping system. The 1 inch of foam on the inside of the block wall got 6 inches of a gravel topped with a floating 6 inch concrete cement pad. The walls are all 2 x 6 construction with stick frame 2 x 6 on 16 inch centres roof trusses and joist. I personally engineered it all, but I took it through the local building department. The local building department charged me about $200 as it also had a 60 amp panel in it.

Yeah the whole build did cost me close to $30,000, Labour not included, but the city put it on as a registered certified outbuilding. I'm not sure if this is what you're looking for or not.

I have also lowered trusses by using Jack posts on every stud and a 12 high foot garage lowering the ceiling to 8 feet. This provided a loft. A city engineer gave approval for replacing the 6 inch joist with 12 inch joist with proper Jack support. The span was only 14 feet.

Reach out to your city engineer with a building permit and it will cost you almost nothing to get good advice. You pay city taxes for this. Why not take advantage.

My good old regular garage, the way I designed it could definitely I have a second floor. I would have to double or triple the 2 x 6 joists for living quarters and I might have to double or triple the studs. But, I would take this through my city engineer.

Not doing it through the city, in 10 years they could mandate nonconformance rip down. If you're trying to skate through the 10 years with engineering advice here. It will not float with the engineer in department of your city!

I'd rather see you make it safe and to engineering specs with your local building department on board, then doing it on the down low.

What's up? Are you scared to take out a building permit with city engineers? Are you afraid of property tax implications? I did not add water to the building. My property taxes or raised $200 a year for the building. I'm not crying. The building upped the property value by easy $100,000.

[cstephens2]

If I use 3/8 bolt grade 9 and make 2x6 oak board, I think it would be just fine. Even 1/2 or 5/8 bolt would be fine. The strength goes up significantly as diameter increases. Can probably be 3/8 x 4 bolts spaced 3 inches in line, and a plate over it, I'm pretty sure nothing would be unsafe about that. I could even make wood 3x6 or 2x12. Like I said wood isn't the issue. I'm pretty sure something could be sorted safely. The only thing is too big of bolts lowers the integrity of the wood so going with smaller fasteners seems better idea than large ones.

"I think it would be just fine". OK. Why bother with all the fancy pants engineering and math, right? Like I said before, you do you boo.

You came asking for advice, and numerous people said to consult a structural engineer. Why not take that advice?

[cstephens2]

as in almost all items there are different quality choices.

https://www.mitek-us.com/products/connector-plates/

I’m willing to bet that there were approved trusses built that had no metal plates and have stood the test of time.

Yes, made from old douglas fir or oak, selected for super straight grain. Modern readily and reasonably cost effective available wood (SPF) doesnt meet these requirements, nor do they have to given the application of structural and materials engineering disciplines.

And I specifically mentioned 'Mitech' in my last post albeit oddly/wrongly spelled, but their availability in less than boxes of 500 seemed nonexistent when I last looked into this.

But whatever, OP can design what he wants and build what he wants.

[Wood Grower]

Drilling holes big enough through a 2x4 for 1/4 steel flitch plates may actually detract from the strength of the 2x4. Putting steel tubing over the end of a truss member may move the shear point of that truss member to a unsatisfactory place.

You are trying to DIY this. IMO Dont.

If I use 3/8 bolt grade 9 and make 2x6 oak board, I think it would be just fine. Even 1/2 or 5/8 bolt would be fine. The strength goes up significantly as diameter increases. Can probably be 3/8 x 4 bolts spaced 3 inches in line, and a plate over it, I'm pretty sure nothing would be unsafe about that. I could even make wood 3x6 or 2x12. Like I said wood isn't the issue. I'm pretty sure something could be sorted safely. The only thing is too big of bolts lowers the integrity of the wood so going with smaller fasteners seems better idea than large ones.

[Wood Grower]

Why use white oak? Sounds like it would cost more than engineered trusses. Unless you want exposed architectural look, and even then its overkill IMO. Douglas Fir would be alot more expensive than standard SPF lumber these days and could probably well be what your stick built roof is made of now.

Well I have a 2 foot diameter clear white oak log 20 feet long. Seems to be cheaper than going to the store for lumber to me.

[Egon]

Just be careful when selecting the 'plates'. For an example, Simpson Strong Tie sells 'mending plates' that clearly state that they are not for truss applications

https://www.strongtie.com/miscellane.../mp_plate/p/mp

The last time I looked into this, the tie plates approved for truss applications were hard to come by in anything less than boxes of 500. They were made from a thicker material and had larger X-Y dimensions than anything commercially readily available. MiTech comes to mind as one supplier.

as in almost all items there are different quality choices.

https://www.mitek-us.com/products/connector-plates/

I’m willing to bet that there were approved trusses built that had no metal plates and have stood the test of time.

[cstephens2]

I am considering that I can use white oak and it would exceed anything that was existing connected with my roof already.

Why use white oak? Sounds like it would cost more than engineered trusses. Unless you want exposed architectural look, and even then its overkill IMO. Douglas Fir would be alot more expensive than standard SPF lumber these days and could probably well be what your stick built roof is made of now.

[cstephens2]

Oh ha ha, when I was thinking plates I was thinking 1/4" or thicker steel drilled with a fastener through the wood and sandwich the wood between to steel plates. I'm sure that thing you show is pretty strong, but actual steel plate must be a lot thicker and heavier duty. Even if I put a square tubing over the end of the wood I could fabricate something that would easily exceed those plates shown. Anyways I might just be pulling the trigger and bulldozing the thing, just am talking about a new garage right today. I still am unsure on sizing though and I guess I need a site survey. 40x60 with 10 or 12 foot wall would probably be ideal.

Drilling holes big enough through a 2x4 for 1/4 steel flitch plates may actually detract from the strength of the 2x4. Putting steel tubing over the end of a truss member may move the shear point of that truss member to a unsatisfactory place.

You are trying to DIY this. IMO Dont.