New Guy, Starting a garage project. Need Truss Help

[lynchmob723]

Hello
I am building a 24x24 garage from scratch. My pitch will be 4/12. I am probably going with a 9' wall because I am limited to a 15' tall building. Sometime in the future I may want to install a lift in the garage so I can jack my car up. I know ill need about 12' ceiling to be able to stand underneath the lift. Would scissor trusses give me enough height in the midde of the garage to do this?

 

[Mike in Ohio]

With a 4/12 pitch on a 24' building you would have 4' of rise on your trusses. I would go with walls at least 10' and maybe 10' 6" and you would still be under your 15' max. Then with scissor trusses you would almost certainly have the room you need. I am not positive but I think with the scissor truss you will pickup about 2' in the center over a regular truss. Good luck, Mike

 

[tatra]

i have the same footprint and 10 foot walls and if i was going to it again i would go with scissor trusses as mike said..........as for insulation. spray foam would be best, but i would wait a year to allow the wood trusses to climatize/ shrink before applying...........

 

[Matti]

I'm told that the inside pitch is half of the outside pitch with scissor trusses. Thus, you will only have 11 feet in the center which may be okay if you want the lift there but likely not. I had the same problem with height restrictions and went with a custom vaulted truss

http://www.garagejournal.com/forum/showthread.php?t=21953&page=2

 

[usa#1]

Go talk to the truss manufacturer you plan on using to supply your trusses. They will be able to show you different designs that would work for you garage and give you exact dimensions for them. You will be able to determine the wall height necessary to get the interior height you want once you know which trusses you plan on using.

 

[lynchmob723]

Thanks for the tips guys

 

[lynchmob723]

So is it true that when I build a 24' wide garage I order 24' wide trusses? I always thought I would order 26' wide trusses for 1' of overhang on each side. Someone told me that it doesnt work that way?!

 

[lynchmob723]

Great thanks. Since I dont care what the overhang is (less is better here since its near the property line) I will prob just order the 24' truss and hopefully it will have a 4" overhang or something close to that. I'll talk to the manufacturer first though

 

[Kevin54]

For a 24' garage, you order a 24' truss and then specify the overhang that you want. For a 24' scissor truss with a 4/12 pitch, the pitch on the inside is one half that or 2/12. On a 24' scissor truss you would gain approximately 26" at the peak or a tick over 2'. And you really would want to have some overhang. Most in stock trusses come with a 1' overhang as standard. Check with a few of your local lumberyards as some do carry 24' scissor trusses in stock. Here is a site that shows some different truss styles. http://www.sbcindustry.com/images/trussconfig/configurations.swf

 

[rancherbill]

As an Alternative to trusses you can try manufactured floor joists. The kind that are I-beams.

You can get them with a longer middle section that allow for lots of insulation.

 

[RobSmith]

Look at a steel frame...I'm an Aussie and we mostly go for the steel frame now. There is much less material and much more interior room. . . .Just a suggestion

 

[kbs2244]

Check into a roof framing method called a “ridge beam”
(Not a “ridge board.”)
You use a strong beam supported at both ends spanning the entire length of the ridge.
Then you can run your rafters from the beam out to the walls with out the need for joists or color ties.
This is because the rafters are now in tension instead of compression.
You end up with a wide open vaulted ceiling inside.

 

[Matti]

Check into a roof framing method called a “ridge beam”
(Not a “ridge board.”)
You use a strong beam supported at both ends spanning the entire length of the ridge.
Then you can run your rafters from the beam out to the walls with out the need for joists or color ties.
This is because the rafters are now in tension instead of compression.
You end up with a wide open vaulted ceiling inside.

This is a very nice design but must be stick built of course. Around here you would need a stamped drawing to get it built though.

 

[Boyd Who]

Can you get a variance so you can go higher?

 

[lynchmob723]

Can you get a variance so you can go higher?

doubt it. Im in St. Paul, so Its quite the urban area. Plus the height of my house is 16' and I wouldnt want the garage towering the house. The beam Idea mentioned above is interesting, but looks more costly.

 

[Boyd Who]

Ah, ok. We have a two-story house so we plan to have a 20' peak height on our garage.

 

[kbs2244]

Building with a ridge beam should be considered "conventual” construction.
It has been around a long time.
It is the way log cabins were built.
A good contractor should be familiar with it.

Some may want to go with a gluelam type beam.
That is the common way in home construction.

But for shops, I prefer a steel "I" beam or a salvaged "Z web" type roof beam.
You can come back later and add a trolley for a chain hoist.

Cost wise you have to compare the high cost of the beam with the lack of the cost of the joists.

 

[Skyline]

Another thing to consider is where the hieght is mesured from. In my case it is from "grade" so since my slab is elevated 1 foot above grade, that reduced my allowable hieght 1' of the building itself.

This can work in your favor as well. For example my current 24x24 garage is 4' below grade at the rear. That means my since in my town, height is measured to average grade, I could go to 17' tall in the front. (I have the same 15' rule as the OP.)

Another option is to go to the local zoning board and ask for more height. The worst they can say is no. My zoning board is fairly strict, with a couple of truely **** individuals, and they still granted me an extra 2'. I would have also changed the grading a bit with a retaining wall, and gotten another foot. Overall, I was now at 20'.

In the long run, I decided to do an end around, and my current plans call for a breezeway to connect to the house, allowing me 30' above average grade, since it's no longer a detached structure. The downside is that I must meet house setbacks, not detached garage setbacks, but that's not an issue for me.