Roof truss question

[FlameOut]

I'm am in the process of planning my new garage (went from 24x24 to now most likely 24'w x 30' x 12' h)

From reading these forums, seems like you always want bigger after it's built

I was concerned about the strength of the prefab roof trusses. With the 24' span, will there be a problem hanging drywall on the ceiling? Seems like quite a bit of weight for the trusses to hold.

I've also been looking online for trusses and prices, but I can't seem to find anything, or anyone local, that sells them. I would think the 24' ones would be fairly common

I'm going with the 12' height because I plan on getting a 2 post lift at some point.

Oh, did most of you design your own garage/workshop, of did you buy plans somewhere? I know I need to submit plans when I apply for my permit, so I'm not sure if they will accept my drawings or not

Bill

 

[Franz©]

I don't recall hearing of many house roofs collapsing because they had drywall hung from the trusses, so I figure it works about the same way in a garage.

 

[rsanter]

go to a truss manufacturer. the trusses are engineered so there will be specs

bob

 

[Gus_Mahn]

From my limited truss experiance, trusses are increadibly strong. On what center will your trusses be? I agree with rsanter contact the manufacturer with any questions.

 

[DynoDave]

I can't imagine a truss design that couldn't handle having drywall applied inside.

The lumber company I bought from drew the building plans. They printed out complete plans, which were acceptable to the building dept.

 

[kbs2244]

You might be able to save some money if you build them yourself.
These schools offer plans.

http://www.public.iastate.edu/~mwps_dis/mwps_web/ut_plans.html#Anchor72045

http://www.ag.ndsu.nodak.edu/abeng/plans/index.htm


Be prepared to prov to an inspector that you built them to spec. (Size of lumber, size of nails, type of glue, etc, etc.

Any big box or lumberyard should be able to get you 24 foot span with 1 foot eves. And they may be cheaper then DIY.

 

[FlameOut]

I was planning on 24" oc. Do places like Home Depot or Lowes carry trusses? I was also a little concerned with having 12' high walls. Just not sure how good it will look, being in a residential neighborhood. Would a lift work with 10' high ceiling?

 

[Charles (in GA)]

You should have a number of truss manufacturers, locally. Most will be happy to talk with you about options that will give you height for lifts, etc. Look in the yellow pages or online.

Charles

 

[boiler7904]

24' span is nothing for a standard roof truss even with drywall on the bottom chord. On commercial projects, we've spanned 70'+ with drywall on the bottom chord. No problems at all. The last truss supplier that I talked to told me that he can confidently design trusses to about a 80' span before things get interesting when it comes to physically delivering to the job site.

Just make sure the truss company knows that you're planning a finished ceiling with insulation above. That will add loading to their calculation. I'd also tell them that you want minimum deflection in the bottom chord - they'll just increase the sizes of some members to make them more rigid.

You'll be able to order trusses through a full service local lumber yard - probably not Lowe's or Home Depot but you can check.

As far as the plans go, talk to the local building department that will review the plans. They'll be able to tell you exactly what they require. Some towns will let you build stock plans without any further documentation. Others will require that you have a local structural engineer or architect review and sign off on the plans as meeting the design parameters for your area.

 

[carcruse]

I got mine from Carter Lumber. They were cheaper than Home Depot and Lowes. Their site shows one in Meadow Lands, Pa. about 18 miles from Pittsburgh.

 

[logical]

For the trusses, go to the lumber yard or building supply place that the builders go to. They likely don't make the trusses, but they have a sub-supplier who designs/builds them. No good truss will collapse under drywall load but you ask a valid question. The most basic truss to span 24' that will hold the roof up just fine will just have 2 x 4 bottom cords and will move some if you are up in the attic storing even lightweight stuff. Talk to the supplier about the next few steps up...storage trusses and actual "bonus room" or 2nd floor trusses. In addition to giving you some attic storage, you are less likely to get drywall joint cracks due to movement.

10' height will certainly work with a lift as long as you don't mind working on your knees. You need to add the height of the upper car, 4 " of platform and how much height you want under the platform. Plus, you may need to package a garage door opener up there too if you use a conventional opener. You are likely to find 12' is needed.

 

[67 455 Bird ragtop]

I was planning on 24" oc. Do places like Home Depot or Lowes carry trusses? I was also a little concerned with having 12' high walls. Just not sure how good it will look, being in a residential neighborhood. Would a lift work with 10' high ceiling?

I purchased my trusses through my local Home Depot. They woek with a local truss company. Their proce was actually cheaper than if I had bought them directly from the truss company. Go figure. My trusses span the 30' portion og my 40x30x12 garage. They also built them to have 14' of open storage space. Ran me about $2500 I believe.

 

[doslocos]

Where ever you get your trusses made they should have an engineer stap on them from the manufacturer. All of the live and dead load info. There are many options for trusses, from different pitches, different looks, hips ect. You can have them design an attic truss and get a room up stairs. Are you going to build this building yourself? If not your builder should be able to help with all these questions. Another possibility is to have the dead load increased so you can mount a hoist to them.

 

[FlameOut]

Thanks for all of the good tips. I'm hoping to have some type of plans ready in the next week or so to take down and get my needed permits. Just need to make up my mind on what size garage I want (or am allowed to build)

I'll be doing all of the building myself. It's been a while since I've done any of this type of building (Over 20 years), but with some help, I should be fine.

I'm going to try to get some prices on trusses today

 

[hawkeye2]

I used 9' studs on my 30-40 shop. I bought trusses with a valuted ceiling. this gives my a interior center height of over 14'. plenty of room for a lift. these were actually cheaper than trusses for a flat ceiling. I specified a 4-12 pitch on the inside and let the truss company figure out the outside slope.

 

[FlameOut]

I used 9' studs on my 30-40 shop. I bought trusses with a valuted ceiling. this gives my a interior center height of over 14'. plenty of room for a lift. these were actually cheaper than trusses for a flat ceiling. I specified a 4-12 pitch on the inside and let the truss company figure out the outside slope.

I like that idea. I'm just worried that if I use 12' studs, it will look to commercial. I'll look into the vaulted 4-12 trusses. I just may have to go to 26' wide though, to help compensate for the angle of the vaulted truss. That extra 1' on each side should do it

 

[JohnZ]

My attached garage is 44' x 58' x 12', clear span, no interior walls or columns, with a 12/12 roof, fully drywall-finished inside, and the trusses are 62' long; my architect had the truss supplier design them specifically for my application; not so much as a drywall pop after seven years.

 

[FlameOut]

That's a nice size span JohnZ. Must be real nice having a garage that size

Hawkeye, what are those vaulted trusses called? I just went to Home Depot to get some prices, and I had a heck of a time getting the guy to understand what I was talking about. He finally called the company they buy the trusses from, and the company faxed him a drawing of what he thought I wanted. It was close, but only gave an extra 16" addition ceiling height above the stud wall height, so if I used 9' studs, I'd only have a 10' 4" ceiling

Oh, got a price of $68, and $104 for the gable ends. Was the same price for a standard 24' flat truss also

 

[doslocos]

In Colorado we call them scissor trusses. The inside pitch is limited by the outside pitch. I would try to find a lumber yard rather than home depot. I don't have any thing against them, but it is hard dealing with a middle person sometimes. I puchase all mine right from the truss plant. They have awesome software and can model it for you so you can see what it will look like.

 

[hawkeye2]

dos locos is right, scissor trusses is the right term. Look in the yellow pages and call the truss company they can build what ever you want, and cutting out the middle man will save you hassles. Here's a web page with pictures of all kinds of trusses.
http://www.pmhi.com/PMHINews-Truss.htm

 

[FlameOut]

A scissor truss isn't the type I was looking for. I wanted a flat ceiling. Looks like the Raided Tie on this page might be what I'm after.

This looks like it would give the vaulted sides, but still be mostly flat for about 3/4 of the ceiling

 

[X73]

I don't think you'll be happy with a 10' ceiling. I'm adding on to my garage now & I have a 10' ceiling, so I went with custom scissor trusses (4th pic down on the right on that page you have linked) that give me an additional 34" above my 10'. This will allow me to use a two post lift & be able to walk under my truck. I would suggest a 12' ceiling or use scissor trusses. I attached a few pictures of mine.

 

[comp]

love the links,,,any other good ones ???

 

[Matti]

My attached garage is 44' x 58' x 12', clear span, no interior walls or columns, with a 12/12 roof, fully drywall-finished inside, and the trusses are 62' long; my architect had the truss supplier design them specifically for my application; not so much as a drywall pop after seven years.

This makes your roof peak at least 34 feet high. I'm guessing there are no bylaws where you live!

 

[boiler7904]

This makes your roof peak at least 34 feet high. I'm guessing there are no bylaws where you live!

A lot of places determine the building height by taking the average of the eave and ridge height for the tallest portion of the main building. So if the eave height was 12' and the ridge height was 18', they would average them to 15'. That's a widely accepted International Building Code standard that would govern your design unless the local building department has amended the code for their jurisdiction.

Things get tricky in urban areas when they start enforcing building envelope criteria as it relates to neighboring properties.

Heights of accessory structures are usually figured to the ridge.

 

[6768rogues]

Truss manufacturers will make whatever you specify as long as the trusses meet local code required loading. In our area, that means 35 lbs. per square foot of snow load.
I ordered mine as 36-foot span, 2-foot centers, 35# top chord live load, lightweight roofing, 10# bottom cord dead load (standard for ceiling with no storage above), 2-foot overhang, 5/12 pitch, 23 standard trusses and 2 end trusses. They made them and dropped them off. Make sure to check the drawing provided with the trusses for bracing, as (typically) compression chords get braced and tension chords do not get braced. You will not know which are compression and which are tension by looking at them if you are not experienced in truss design. Save the drawing so that the inspector can check your bracing to the design criteria.

 

[Matti]

A lot of places determine the building height by taking the average of the eave and ridge height for the tallest portion of the main building. So if the eave height was 12' and the ridge height was 18', they would average them to 15'. That's a widely accepted International Building Code standard that would govern your design unless the local building department has amended the code for their jurisdiction.

Yeah that would still be 23' high to the roof mid-height. The local bylaws here are 12' although they are upping that a bit in the mature neighborhoods. I'm waiting for the bylaw change before applying for a permit!