Architects and General Contractors - Space Ques

[2002 Maxima SE]

Hi All,

For the new year, I am thinking about starting a project that has been on my mind for 8 years. Above my garage I have a bi-level attic. The upper part is separated from the lower part by joists. The upper part houses my hvac and a very narrow part for storage.

The lower part (front of the house) has a small space...maybe just enough for more storage and hopefully a small office.

This thread on lifehacker.com got me motivated (http://lifehacker.com/5871671/the-warm-attic-workspace).

A few questions:

Those joists support the roof over the garage (only the roof). Is it possible those joists could be removed or relocated?

 

[JOD]

Sorry, but there's going to be no cheap, easy way to accomplish this. You're looking at modifying engineered trusses, which by definition are built as light as possible. So, once you start cutting into them, you're gonna have to add material elsewhere (like rafters and floor joists). In most places, once you start cutting trusses you have to have a structural engineer sign off on it in order for it to be to code. Otherwise, you'd have do completely rebuild that section according to building code span tables so that engineered trusses aren't required. And in looking at it, the center support for the trusses looks like it would hit so low that it wouldn't buy you that much space.

Not what you wanted to here, but that's my eyeball take on it.

 

[2002 Maxima SE]

Crud! Well, Plan B was to just add a drop ladder and use it only for extra storage. Thanks for reviewing the pics, much appreciated.

 

[MNgopher]

I was thinking the same thing. All those stamped metal plates are a sure sign of engineered trusses, and they are as economical as is possible. Any modifications at all will require a structural engineer to sign off. Best bet if you still want to go this route is to get an engineer/architect to meet with you and find out what you are in for.

Long story short, more work than you'd think to begin with.

 

[Clevy]

Engineer. Are you kidding me. A decent framer can header off some space up there. The picture posted is what I do for a living. Metal ties are called gussett plates.
Op. I promise you it wouldn't be cost effective to try to make some space up there. However a carpenter could give you some viable options. You don't need an engineer or code this that or the other.
Keep your mouth shut about what your doing up there and find a carpenter you trust. You could easily joist a floor above and cut out one of the truss members however you need to tie everything to something.
Don't give up. Call a carpenter. Not an engineer.

 

[MNgopher]

As a licensed engineer, all I'm going to say is that avoiding code is generally not a good choice.

Messing with engineered trusses is not a good choice without guidance, no matter what the carpenter says is a good idea. You should see some of the jokers we see in the field...

 

[hattaresguy]

Its a truss roof, only way to change it is remove all the framing from the walls up and re frame with conventional, if that's even possible using the existing structure without adding a lot of interior support.

When a structure is framed using engineered trusses all the load is being put on the two outer walls, ie front and back of the garage usually depending on how they are run. The left and right walls and all interior walls are just for show. You can do this with conventional framing but it gets expensive fast. I just did this on a garage, I used two steel I beams to support 30ft long 2x12 roof joists, and the beams spanned 40ft clear and have trolly's that run on them for lifting up to a ton.

Trusses are engineered, if you start hacking them up and putting a lot of [censored] up their your roof will come down.

 

[Hokiefyd]

OP, where in North Carolina do you live? Your attic space looks EXACTLY like mine. I mean, in terms of the truss layout, the "notch" in the roof. Is this your attic space over the garage?

 

[rjundi]

Originally Posted By: MNgopher
You should see some of the jokers we see in the field...


+1, never practiced in design but I have a MS in Civil/Structural engineering.

 

[Pop_Rivit]

Originally Posted By: Clevy
Engineer. Are you kidding me. A decent framer can header off some space up there. The picture posted is what I do for a living. Metal ties are called gussett plates.
Op. I promise you it wouldn't be cost effective to try to make some space up there. However a carpenter could give you some viable options. You don't need an engineer or code this that or the other.
Keep your mouth shut about what your doing up there and find a carpenter you trust. You could easily joist a floor above and cut out one of the truss members however you need to tie everything to something.
Don't give up. Call a carpenter. Not an engineer.


I think we need a contest to see who can come up with the worst advice this year, and I'd like to nominate this thread as a contender in 2012.

By the way, they are "gusset" plates, not "gussett" plates.

 

[JOD]

I know you're probably wondering "lots of people open up their attic space, like the guy in the posted link, what's the big deal". Why is Clevy's advice so bad?

This issue is that most (older) houses use stick framing, where the load is supported by lots of wood. They were built when labor was cheap and people thought wood grew on trees... Engineered trusses, like the ones in your house, are a different, newer method. They use less wood, less labor to install at the site, are lighter and typically stronger over the long haul. The downside? They don't take well to modification. Yes, it can be done, but to modify an engineered truss isn't a matter of just cutting it and replacing some wood. They're built as light as possible (that's the whole point), so randomly cutting them is just a bad idea unless you know how much material, and where, you need to add. Standard construction has plenty of margin for error, and lots of the wood isn't actually doing much. That's not the case with engineered trusses.

The other issue is that one thing tied to another. Will the top plate support heavier rafters? Will the walls support the(now) heavier top place? And so on.

Sorry if any of this seems oversimplified, but since you asked the question I figure it would be good if it were spelled out better for you, and you understood why randomly cutting into engineered trusses is a really bad idea. Bottom line is that if "a carpenter you can trust" suggests cutting into those trusses, make sure he has an engineering degree... Otherwise, he's not a carpenter I'd trust.

 

[tom slick]

Those gusset/gussett/gussette plates are called "gang nails" around here.

 

[sleddriver]

I coffered the ceiling in my kitchen years ago and hired a CE so I wouldn't run into any problems down the road. The chords/diagonals/rafters are all tied together and can't be cut on a whim.

Consult an archy or engineer FIRST.

 

[hattaresguy]

Yeah a lot more hack jobs out their than good framers and carpenters. Most guys don't really care, just want to get paid and move on, and when your ceiling is sagging 6 months later are not reachable.

I like truss roof construction I order a ton of them each year. But the only downside is attic space is tight. I get around this by using cathedral ceilings where I can, and the rest is filled up with a lot of insulation.

Storage? ehh not so much.


BTW not wild about the OSB they used on your sheathing, IMHO it doesn't hold nails as well as a 1/2 5 ply or a 5/8. But it costs about half as much to buy. Also doesn't look like they used clips between the plywood joints that ride in the center of the trusses. I wouldn't strip that roof unless you have to.