Loft Truss Span

[Grug]

Ok, so I've introduced myself in the introductions section. Now I'm ready to pose my first question.

I'm thinking about a steep pitch 26X26 garage with a loft area (I've Googled loft style trusses). So, can a fella' span that much distance with a truss and not have to use any jack posts in the middle of the garage?

The loft area will simply be for storage; nothing super heavy.

Cheers!
Grug

 

[bczygan]

Certainly!

What kind of load do you intend for it to support?

Simply talk to your local truss company to find out the costs.

 

[astroracer]

26' span is exactly what mine is. 26 x 28 with loft trusses. 14 x 27 usable space in the loft. Sorry about the snow.

And remember! There is a TON of storage in those knee walls. insulate the entire roof and put floors in the knee walls. Add plywood doors and build in bookcases and display shelves. I did!
Mark

 

[mlammerhirt]

Any pics of the loft space? Also how do you access your loft....pull down attic stairs or a stair case? Very interested in this thread, I will be building a similar garage in the future?

Sent from my XT1254 using Tapatalk

 

[matt_i]

I am building 25 x 40, on a 6:12 pitch roof. I have 12' of clear span storage in the attic truss. It cost roughly 2x as much as a standard "W" shaped truss. But, pretty cheap additional storage space for 12 x 40 = 480 sqft. The additional cost is in the timber, 2x10 bottom chord and 2x6 top chords. The truss company designed it all, except for the distance "between the blocks" on the bottom, (actually the outer dimension of the double top bearing plates atop the walls) the roof pitch and the amount of overhang. Its all clear span. In a 10:12 or 12:12 pitch roof you will likely be able to stand up and walk down the center without stooping.

Edit: this is all clear span. No big deal for the truss co.

 

[Grug]

Looks great, Mark!

So, you have no jack posts or any type of load bearing wall in the 'middle' of the lower portion of your garage? It's all completely open space? Your outer walls are carrying all the weight?

One of the contractors I've been having discussions with seems to think I'll need one (or more jack posts). That just doesn't seem right.

And to bzcygan, the loft of my proposed garage will be basic storage. Christmas lights, a few old air cooled VW parts, patio furniture (that kinda' thing). It will never be an apartment or anything like that.

Thanks for the prompt replies, folks!

Cheers!
Grug

PS, No worries on the snow. Old Man Winter just pounded us yesterday and reminded me of who's really in charge.

 

[LB-1911]

One of the contractors I've been having discussions with seems to think I'll need one (or more jack posts). That just doesn't seem right.

I would consider contacting a truss manufacture in your area.

From a previous thread -

You are looking for "Attic storage" trusses. I had some made to span my 26 foot wide garage. The pitch is 8/12. I have a 10 foot wide by 8 foot tall area in the truss. If only cost a $250 more than normal trusses, so it was not very expensive. My trusses can take 40 pounds/square foot, so I can store a lot of weight in my 10x30 ft room.

 

[bczygan]

Looks great, Mark!

So, you have no jack posts or any type of load bearing wall in the 'middle' of the lower portion of your garage? It's all completely open space? Your outer walls are carrying all the weight?

One of the contractors I've been having discussions with seems to think I'll need one (or more jack posts). That just doesn't seem right.

And to bzcygan, the loft of my proposed garage will be basic storage. Christmas lights, a few old air cooled VW parts, patio furniture (that kinda' thing). It will never be an apartment or anything like that.

Thanks for the prompt replies, folks!

Cheers!
Grug

PS, No worries on the snow. Old Man Winter just pounded us yesterday and reminded me of who's really in charge.

That contractor is ignorant of the facts, and even worse, he is acting as if he knows what he is talking about. Show him some of the solutions in this thread and ask him how they did that. This is why he is a contractor, not an engineer.

Have you considered a gambrel roof truss combined with floor trusses for an actual 2nd floor? Compare pricing.

Bill

 

[bczygan]

An upgrade from the storage trusses shown and discussed above is this:

Use floor trusses or wood Ibeams for the floor/ceiling joists. This will give you a depth of member that a storage truss will not, so you can install adequate insulation in the ceiling.

Then, instead of dimensional lumber for the rafters, use engineered rafters. This will create an open space with no need for knee walls. These also have additional depth, which provides space for insulation so the space can be inhabited. Typically though, not enough for FG insulation. Foam is the best option.

As with every other option, consider the cost versus the benefits.

Bill

 

[astroracer]

Looks great, Mark!

So, you have no jack posts or any type of load bearing wall in the 'middle' of the lower portion of your garage? It's all completely open space? Your outer walls are carrying all the weight?

One of the contractors I've been having discussions with seems to think I'll need one (or more jack posts). That just doesn't seem right.

And to bzcygan, the loft of my proposed garage will be basic storage. Christmas lights, a few old air cooled VW parts, patio furniture (that kinda' thing). It will never be an apartment or anything like that.

Thanks for the prompt replies, folks!

Cheers!
Grug

PS, No worries on the snow. Old Man Winter just pounded us yesterday and reminded me of who's really in charge.

Thanks! I designed the garage and the entryway between it and the house. The pitch is a 6/12. To access the office space there is a stairway on the back wall (to the left in the picture). 3' wide full access stairway. There is NO jack post in the middle of the garage. This garage/office was built in 1996 and there is ZERO sagging or settling.
I used 5 sheets of 1/2" oak veneer plywood to make the doors. There is one set of built in strorage drawers, one set of covered storage shelfs and three built in bookcases with storage behind them in the cubbies.
I also built a divider wall to separate the computer area from the living space with display shelves built into the divider walls. I'll get pics.
Mark

 

[Grug]

Oh my goodness...this site is a goldmine!

Starting tomorrow morning, I'm gonna' start looking for local truss manufacturers.

 

[bczygan]

Oh my goodness...this site is a goldmine!

Starting tomorrow morning, I'm gonna' start looking for local truss manufacturers.

When you talk to them, they will either want to know from you, or they will suggest themselves, what the load capacity of the storage truss will be.

There will be two load factors.

One will be for the roof loading, which will have snow and wind load components based on your location.

The other one will be the floor load capability for the storage area. Here in the US, typical residential living spaces usually have a 40#/square foot live load rating. That is for an occupied space, so for storage they may suggest less. It's something to think about and discuss. Also let them know if there will be a finished ceiling on the underside of the trusses. This effects the allowable deflection.

Bill

 

[Stuart in MN]

My garage is 24' with a 10/12 pitch roof, instead of 26', but this picture gives you an idea of the space available up there (this was during construction and before the floor was put down:

The space is 12' wide, and with 3/4" tongue and groove plywood glued and nailed down for the floor it's pretty sturdy. In my case, I just told the builder what I wanted and they sourced the trusses; if you're doing the build yourself you'll have to find a local source. Chances are you can order them from any decent local lumber yard or even the big box stores.

 

[srleen2]

I used a combination of attic trusses and scissor trusses for my garage build with a 30' clear span.

Around here the truss mfrs will talk to you somewhat, but only deal with lumber companies to retail their trusses to actually buy them.

Thread here

 

[theoldwizard1]

Attic trusses give you the storage you want. You just have to determine the width, roof pitch and storage load.

Scissors trusses give you a more "open" area that you can build your own loft using posts resting on the floor (a "real" foundation is recommended for heavy loads).

Vaulted parallel chord trusses give you even more volume.

 

[YukonXL04]

My garage is 24' with a 10/12 pitch roof, instead of 26', but this picture gives you an idea of the space available up there (this was during construction and before the floor was put.
The space is 12' wide, and with 3/4" tongue and groove plywood glued and nailed down for the floor it's pretty sturdy. In my case, I just told the builder what I wanted and they sourced the trusses; if you're doing the build yourself you'll have to find a local source. Chances are you can order them from any decent local lumber yard or even the big box stores.

Do you have a build log anywhere? Any more details on your building? Really contemplating doing attic trusses on my 24ft wide garage.

 

[Stuart in MN]

Do you have a build log anywhere? Any more details on your building? Really contemplating doing attic trusses on my 24ft wide garage.

I don't have a build thread, I built my garage before the Internet so I only have a picture or two of it here. It's 24 x 40, and pretty conventional otherwise. In my opinion attic trusses are the way to go, in my case they weren't that much more expensive than conventional trusses and you gain all that storage space.

 

[Grug]

Stuart, that image you included of your garage loft area is exactly what I'm looking for. Even the spaces between the trusses could be utilized for my many boxes of Christmas lights (just call me Clark Griswold) I'm assuming those trusses are 24" on centre?

Bill, you referenced 'allowable deflection'. I Googled it quickly and it appears to be 'movable sag' in the truss that could crack a gyprock ceiling. That right? My plans are for no ceiling at all; just the exposed bottoms of the trusses. I envision a floor in the loft of either spruce boards or aspenite.

I'm gonna' search the board for how to upload pictures and show you folks my proposed sight.

 

[Dhagan887]

Best thing I ever did to mine! Price difference was minimal, couple hundred bucks and my garage is the same size +/- a few inches. With an 8/12 roof I ended up with 10' of extra storage space. Only ~ 6'4" ceiling height, but it's plenty enough for me.

One thing to consider is access to it. I did not want to give up the floor space for stairs and went withe a standard 22x54 pull down. I can't get 4' sheet goods through the opening, and some other things are very tight on the width. Next time I think I would set up for a minimum 25" but probably go with the 30". Something to consider with the truss designer depending on which way you would want the opening turned.

 

[Stuart in MN]

Stuart, that image you included of your garage loft area is exactly what I'm looking for. Even the spaces between the trusses could be utilized for my many boxes of Christmas lights (just call me Clark Griswold) I'm assuming those trusses are 24" on centre?

Yes, they are 24" on center. For access I have a standard fold up attic ladder, installed in between two of the trusses at the far end.

 

[Onewolf]

Our new detached garage/workshop has 34ft clear span with light storage trusses. The storage trusses have a BC rating of 10lbs/sq ft. We just wanted to store lightweight christmas/halloween/misc stuff up there.

 

[Grug]

Ok, now you folks have me thinking about access to the loft.

I don't really want a fold up ladder. I'd like permanent stairs. I never thought how a 24" truss gap could affect a set of stairs. I'm assuming stair treads are about 36" (certainly more than 24").

Hmmm...

That's an awesome garage, Onewolf! With a garage like that, my wife would never see me.

I also checked out your build log. Couldn't get over all the sand! I had to have sand trucked in from almost 45 minutes away when I installed my home's septic system.

 

[LB-1911]

Ok, now you folks have me thinking about access to the loft.

I don't really want a fold up ladder. I'd like permanent stairs. I never thought how a 24" truss gap could affect a set of stairs. I'm assuming stair treads are about 36" (certainly more than 24").

Hmmm...

This might give you an idea or two....

Stairs are in.

Stair measurements:
16 steps total including the lower landing as a step and counting the final step onto the attic floor
8" rise and 11" run for each step (not including overhang of tread)
31" vertical from concrete floor to top of lower landing
124-1/4" vertical from concrete floor to top of attic floor
83" headroom from lower landing to bottom of floor joist
83" headroom (approximately) when standing at top of stairs in attic
41" stair width not including knee wall (i.e. stair treads are 41" wide)

I'm not happy with the length of the wall underneath the steps, so I've asked the builder to remove part of the wall. The wall is 43-1/2” long, which leaves 183" horizontal clearance to the far wall. Since one of my goals for this garage was to be able to fit a car parked perpendicular against the back wall, I would like to have as much horizontal clearance as possible. I hope to shorten this wall to not much more than 24" long to accommodate a sink. That would leave 202" horizontal clearance to the far wall and a minimum of 35" vertical clearance for a car hood at the edge of the stair wall.

The staircase has four stringers reinforced by one 2x4 on each side nailed to the outboard stringer. It seemed pretty solid even before they built the wall underneath the staircase, so I don't think shortening this wall will cause a problem.

New 24’x34’ Detached Garage with Attic Trusses

For those who are just starting this thread, here are some photos of the new garage as of August 2015:

 

[Rigpig]

LB, that's a great looking shop! That finished loft looks amazing, and i installed 4 skylights in mine as well, really enjoy the natural light.

Grug, i changed my trusses at the last minute and went with an 8/12 pitch i think it was... Best decision i made. I've got a build thread on here as well(32x36), haven't updated in a while but there are a bunch of pictures of the same idea. I went with stairs off the back of the shop, to not use up internal space, and i have a stream at the lower end of the property so the deck leading into the loft is a nice area to sit and sip a coffee in the morning.
Good luck and keep us posted.

 

[LB-1911]

LB, that's a great looking shop! That finished loft looks amazing, and i installed 4 skylights in mine as well, really enjoy the natural light.

sd171's Garage Build Thread is @
http://www.garagejournal.com/forum/showthread.php?t=245711

 

[Grug]

...
Grug, i changed my trusses at the last minute and went with an 8/12 pitch i think it was... Best decision i made....

Hey there, Rigpig. So what was your original plan for truss slope? More or less than 8/12?

I'll try and search out your build thread on the site.

Cheers (from the east coast, BTW)!
Grug

 

[bczygan]

Stuart, that image you included of your garage loft area is exactly what I'm looking for. Even the spaces between the trusses could be utilized for my many boxes of Christmas lights (just call me Clark Griswold) I'm assuming those trusses are 24" on centre?

Bill, you referenced 'allowable deflection'. I Googled it quickly and it appears to be 'movable sag' in the truss that could crack a gyprock ceiling. That right? My plans are for no ceiling at all; just the exposed bottoms of the trusses. I envision a floor in the loft of either spruce boards or aspenite.

I'm gonna' search the board for how to upload pictures and show you folks my proposed sight.

Exactly,

We use the word "Deflection". **** sag. Structural members deflect.

L/240 is OK for no ceilings below. L/360 for drywall ceilings below. I would use L/360 for stiffness anyway.

So with no ceiling, how are you going to keep the insulation in place?

Bill

 

[Dhagan887]

Yeah access was a huge problem with the layout I had in mind for my garage. Basically where the stairs had to go if I wanted them ate up the corner where my bench needed to be and would make me move the fridge/deep freeze out an already partially wasted corner to eat up 8 feet of other good area. Also woul basically have no room to walk around the truck (crew cab f250) unless I left the left front open and pulled in at an angle. Basically made for a one car garage with a terrible layout.

Edit: that's why I went with the pull down knowing it would just be storage anyway. Just wish I had went bigger on the pull down.

 

[Grug]

So with no ceiling, how are you going to keep the insulation in place?

Bill

For now, no plans for insulation or a heat source. I will throw some insulation in the corners where the studs meet.

Maybe down the road I'll install an airtight woodstove and insulate.

 

[Rigpig]

sd171's Garage Build Thread is @
http://www.garagejournal.com/forum/showthread.php?t=245711

Sorry, should have looked closer that it was someone else's build!

Hey there, Rigpig. So what was your original plan for truss slope? More or less than 8/12?

I'll try and search out your build thread on the site.

Cheers (from the east coast, BTW)!
Grug

Hey Grug,
My original plan was a simple 4/12 pitch, and i knew that with all my junk and losing a room/office in the house to "Jr." meant an office/storage elsewhere-in the shop-!
I quickly had the tech/engineer at the truss shop change plans to accommodate a workable area/office and ok'd by my inspector.
I like the pull down staircase and built-in stairs, but didn't want to lose the bench space, so i built stair access off the back.
Being that its considered a "livable space"(loft), you'll have to vapour barrier the ceiling and insulate(R-40) the ceiling/sheet it also(5/8's ceiling vs.1/2 walls), acts as a fire-stop to the upstairs.
But check with your local inspector.
Also, my insurance people didn't like the wood stove idea, not many places would not insure me with one, so i went with a propane Mr.Heater.
Good luck, and Cheers from the "Wet" coast!