Roof truss questions

[davidfite1978]

My shop roof has some kind of weird truss system that I have never seen. It is made of 2x4's only, and I think 24" on center (need to measure to double-check). The joists are either 3 or 4 pieces connected end-to-end, it's about 24 feet or so (again, need to double-check, but close enough for this conversation. Probably 4 - 8ft - 2x4's connected) I have several questions...

1.does anyone know what the name of this system is called?
2.can I safely insulate the rafters?
3.can I safely insulate the ceiling joists?
4.can I safely add a drywall ceiling or drop ceiling?
5.can I safely add any storage?
6.any other thoughts?

I uploaded a drawing I made that roughly shows how it's designed. Where the joist 2x4 pieces meet, there is a wooden plate (plywood) connecting the 2 joists and 1 column coming down
thanks guys

 

[bczygan]

I would call it "jury rigged".

It obviously holds itself up, but I would worry about additional loads.

What area are you in?

First I would measure the deflection on the rafters and then the joists.

I would be very careful about the weight of the roofing material. What is the decking and roofing?

The safest solution is to install new intermediate ceiling joists, sized for the span and the load of a ceiling and insulation. It would be NECESSARY for a drywall ceiling.

You might get away with a suspended ceiling, or a lightweight metal one, along with ceiling insulation.

Bill

 

[davidfite1978]

I'm in central Kentucky.

The decking is plain old plywood. 23/32 I think. It has dimensional shingles.

I really like having it open so I can hang stuff here or there if needed, but I also would like to insulate for heating/cooling. I don't necessarily want a finished ceiling, just something so I can insulate. Thought about just insulating the rafters (with vents too of course) so I could leave the ceiling open but still get some good heat/AC going. I dunno... I'm perplexed. And I have a feeling any new joists I have to buy to add/fix anything is going to be expensive since it's such a wide span.

 

[Onewolf]

I'm no truss expert, but I've never seen anything like that. "Hey Billy Joe Bob, hold my beer while I work on the the new truss design."

 

[davidfite1978]

I'm no truss expert, but I've never seen anything like that. "Hey Billy Joe Bob, hold my beer while I work on the the new truss design."

I know... It's been there for 30 years at least, so it's got to be somewhat "sound", but man... never seen anything like it.

 

[Kevin54]

I'm no truss expert, but I've never seen anything like that. "Hey Billy Joe Bob, hold my beer while I work on the the new truss design."

Exactly!!!!!

You don't have a truss system, you have rafters that someone decided to hang some 2x's off of for intentions of having a ceiling sometime on down the road.

They wanted to support the ceiling joist, using the rafters for support.

Personally.....if it were me, and I wanted to make the garage really nice, I'd rip everything off down to the square, and then put some proper rafters up. But that's me, and the way I am about certain things. I don't know how much money my dad spent over the years, and how many hours I spent helping him, cobble up the roofing system to get the ridge level without a sag in it, to redoing things to try and get the sag out over the garage door. It was always dad's way or the highway. I tried to talk him into proper trusses for years, but it was always too much money, yet over the years, he probably spent 4x's that amount rigging things up.

 

[sands35]

Yeah - those are pretty sketchy.

What I'd do is take some basic measurements then cross reference those with rafter span tables to back into the allowable load limits. If you are under-designed, then you should think about sistering in new rafters with the proper dimensions.

I dunno, might be an optical illusion from the photo, but are the rafters still straight?

It doesn't look like there is a collar or rafter tie?

 

[davidfite1978]

No collar/rafter ties. The house doesn't have any either. I'm in process of adding those to the house. I'm assuming I should probably add some to the shop too?

Rafters seem to be straight from what I can remember, I'll have to check. Nothing sticks out though that I can remember. The joists are a little wavy, so that if I were to drywall it'd be super-wavy looking and not flat, but everything is straight I think.

 

[Falcon67]

Yep, I've seen that style in farm sheds and some older 60s build garages. The "rafter ties" are the bottom chords. Problem is, they are in 8' pieces and not spliced together with any kind of real strength. Just nailed to the pieces of 2x4 hanging from the rafters. Not something I'd want to load, but it apparently works barely well enough.
1) No
2) sure, why
3) I wouldn't like they are
4), 5) No IMHO
6) glue and screw 2x10x24 #1 or better (or 2x12x24 ) to the bottom "cords" of those things to give it some real rafter ties, then you could put in a ceiling, insulation and storage.

 

[davidfite1978]

6) glue and screw 2x10x24 #1 or better (or 2x12x24 ) to the bottom "cords" of those things to give it some real rafter ties, then you could put in a ceiling, insulation and storage.

I like the sound of this option. I could do that 1 at a time, as I had the time/money/help. All of the walls are 2x4 construction as well. Would it be ok to do this option knowing the walls are 2x4 as well? I just don't want to overload anything.

 

[DekeT]

Exactly!!!!!

You don't have a truss system, you have rafters that someone decided to hand some 2x's off of for intentions of having a ceiling sometime on down the road.

They wanted to support the ceiling joist, using the rafters for support.

Personally.....if it were me, and I wanted to make the garage really nice, I'd rip everything off down to the square, and then put some proper rafters up. But that's me, and the way I am about certain things. I don't know how much money my dad spent over the years, and how many hours I spent helping him, cobble up the roofing system to get the ridge level without a sag in it, to redoing things to try and get the sag out over the garage door. It was always dad's way or the highway. I tried to talk him into proper trusses for years, but it was always too much money, yet over the years, he probably spent 4x's that amount rigging things up.

If I walked in that garage I would walk right back out.

 

[bczygan]

Step 1 - Measure span.

Step 2 - Find required loads to use for calculations in your location and zoning and use.

Step 3 - Find span tables for joists and for rafters and find out sizes and species needed for loads and spans. Design joists for ceiling and insulation load you decide on. Don't forget the weight of any additional furring or nailers.

Also:
Check existing rafter deflection.
When re-roofing is due, consider lighter roof, such as metal.

I suspect thst the roof structure is adequate to hold itself up and little more. Extreme wind and or snow conditions coupled with a too heavy ceiling and insulation and hanging some things from it could cause partial or complete failure. You just don't have a way of knowing without investigation and calculations.

As it stands now, everything is supported by the rafters.

Remember this: Doing calculations, or engineering is nothing more than finding out what your structure's capabilities are, so you know what the structure can and cannot do.
Engineering can also give you answers as to cost.

There are numerous ways to reinforce or even replace the structure you have, to give you various capabilities.

So, first you can investigate the existing structure's engineering, and see if it will do any of the things you wish without modification.

If not, you can see if any of the range of possible modifications will give you the capabilities you want.

Price each method, based on each alternate solution and you will have your choices.

A drywall ceiling will undoubtedly require the most reworking.

Bill

 

[kengoff]

Honestly I would replace it (the roof) while you have it tore down to what you have. Manufactured trusses is the way to go.

 

[rburke65]

The wood that is pictured is NOT a truss! Pretty scary.....IMO!

 

[Mike in Ohio]

It looks to me like a previous owner copied an end truss and just built a bunch of them. The problem looks to me (I am no engineer) that end trusses are usually supported by the end wall so they don't always carry the weight of a regular truss. That being said the most I would consider would be a thin guage light weight metal ceiling with a little insulation laying on top. Or maybe better still 1 1/2 or 2 inch 4 x 8 sheets of Styrofoam insulation used as the ceiling. Individually the sheets weigh almost nothing but I have no idea what the total weight would be for your whole ceiling.

Clearly those "trusses" are built heavy enough for what they need to do, but I don't think they can do a lot more than that.

 

[davidfite1978]

Thanks for all the comments/suggestions. I appreciate the different perspectives. I measured it last night and looks like right at 24', so my plan will probably be to find some 2x12x24 lumber and start sistering them to the bottom cord, and then expand from there.

 

[Kevin54]

Thanks for all the comments/suggestions. I appreciate the different perspectives. I measured it last night and looks like right at 24', so my plan will probably be to find some 2x12x24 lumber and start sistering them to the bottom cord, and then expand from there.

I don't appreciate these comments though...

I thought this was a forum to get help and share ideas with? Not the "my garage is better than yours" contest. Pretty immature for a "senior" member...

I didn't see what comments that you DIDN'T appreciate, but a word of advice since you are relatively new......get a little thicker skin. And don't take that wrong as I'm, not saying it as a put down to you, but just a suggestion as to how to let some of the remarks roll off. Some members don't mean to sound disrespectful, but the smilies are the only way to show what attitude you have when replying as the internet cannot actually let a person see or hear emotion. But on the other hand, some peoples responses can really be ******, and the reply typed out with no thought to the member they are replying to.

ANd before I forget....Welcome to Garage Journal. Don't let a few bad or smartass replies put a vision in your head as to what the site as a whole is like. I've been on this site from the very beginning, and you'll find more helpful people on here than any other site. And if you are working on a project, and need an answer, you can normally ask on GJ, and have your answer within 15 minutes. The members really come through to help others.

With all of that being said......your 2x12x24' boards, You will have a small fortune in just one, let alone getting a quantity of them. Look at your standard truss design. It is made out of nothing but 2x4's. Quite a few people have made their own trusses, and are probably better, or stronger than the standard 24' 4/12 truss.

Make your own. Get on Craigslist under materials, and do some shopping for some 2x4's and some 7/16 OSB, or if you have the money, buy new. Keep your top rafter, keep your bottom chord, then add your webs between the two (rafter and chord) Where a standard truss has metal plates, you can glue and screw OSB to the sides of what you are making, only make your plates considerably larger. Just as in from the wall going towards the center, instead of a small plate in the corner area at the wall, make a larger, possibly 3' wide OSB triangle on each side. Once you get one truss made and completed, then you'll have your dimensions, and can work on the others as you have time and money

 

[davidfite1978]

I didn't see what comments that you DIDN'T appreciate, but a word of advice since you are relatively new......get a little thicker skin. And don't take that wrong as I'm, not saying it as a put down to you, but just a suggestion as to how to let some of the remarks roll off. Some members don't mean to sound disrespectful, but the smilies are the only way to show what attitude you have when replying as the internet cannot actually let a person see or hear emotion. But on the other hand, some peoples responses can really be ******, and the reply typed out with no thought to the member they are replying to.

ANd before I forget....Welcome to Garage Journal. Don't let a few bad or smartass replies put a vision in your head as to what the site as a whole is like. I've been on this site from the very beginning, and you'll find more helpful people on here than any other site. And if you are working on a project, and need an answer, you can normally ask on GJ, and have your answer within 15 minutes. The members really come through to help others.

With all of that being said......your 2x12x24' boards, You will have a small fortune in just one, let alone getting a quantity of them. Look at your standard truss design. It is made out of nothing but 2x4's. Quite a few people have made their own trusses, and are probably better, or stronger than the standard 24' 4/12 truss.

Make your own. Get on Craigslist under materials, and do some shopping for some 2x4's and some 7/16 OSB, or if you have the money, buy new. Keep your top rafter, keep your bottom chord, then add your webs between the two (rafter and chord) Where a standard truss has metal plates, you can glue and screw OSB to the sides of what you are making, only make your plates considerably larger. Just as in from the wall going towards the center, instead of a small plate in the corner area at the wall, make a larger, possibly 3' wide OSB triangle on each side. Once you get one truss made and completed, then you'll have your dimensions, and can work on the others as you have time and money

I removed my comments. While I agree to have thick skin when you're on the internet, I also know there was no "smiley" or "LOL" on the comment, so it was rude nonetheless. I guess I just have different standards than some people. I would only post something like that to someone I knew personally and knew how they would take it. Any-who... thanks for the suggestion about building new trusses. Gonna try and find a structural engineer I can get some free advice from, and explain to him the options you guys gave me and see what he says.

 

[DekeT]

I removed my comments. While I agree to have thick skin when you're on the internet, I also know there was no "smiley" or "LOL" on the comment, so it was rude nonetheless. I guess I just have different standards than some people. I would only post something like that to someone I knew personally and knew how they would take it. Any-who... thanks for the suggestion about building new trusses. Gonna try and find a structural engineer I can get some free advice from, and explain to him the options you guys gave me and see what he says.

The only free advice you are going to get from a structural engineer is:

1) Hire a general contractor to rebuild your roof.
or
2) Hire me to design you a fix.

Your problem for adding load is limited by the strength of the rafters.
Reinforcing the bottom chord without increasing load on the rafters will require a 24 foot board setting on the plates. Only LVLs are that long. Unlikely that board will match up with the sag in bottom chord.

 

[davidfite1978]

The only free advice you are going to get from a structural engineer is:

1) Hire a general contractor to rebuild your roof.
or
2) Hire me to design you a fix.

Your problem for adding load is limited by the strength of the rafters.
Reinforcing the bottom chord without increasing load on the rafters will require a 24 foot board setting on the plates. Only LVLs are that long. Unlikely that board will match up with the sag in bottom chord.

I've seen several places where I can get 2x12x24 pine lumber. Lowe's had it on their website but it's gone now for some reason. IF I can find it, would that be OK? Or is a 2x12x24 that's not an LVL inherently bad for this sort of thing? I also found a couple of other posts similar to my problem on other forums where the OP installed 2x12x24 pine lumber and fixed their problems. We have a salvage place nearby that tears down big old buildings and stuff so I was hoping to check it out and maybe find some for cheap.

 

[Falcon67]

Go try a "real" lumber yard - not Lowes or HD. McCoy's here stocks 2x12x24' lumber. I forget the type, but it's not pine or SPF. I wanted 2x4x10 for my 24' span, but I would have had to buy 40 pieces (bundle) and only needed 19 - not a stock item. And yes, mine sit on 2x4 plates. It's preferred that the joist sit on a stud, so you could consider sistering the studs also. 2x4s are cheap.

My 2x12x24 joists:

I did some old shed saving here:
http://www.garagejournal.com/forum/showthread.php?t=41042

 

[davidfite1978]

Go try a "real" lumber yard - not Lowes or HD. McCoy's here stocks 2x12x24' lumber. I forget the type, but it's not pine or SPF. I wanted 2x4x10 for my 24' span, but I would have had to buy 40 pieces (bundle) and only needed 19 - not a stock item. And yes, mine sit on 2x4 plates. It's preferred that the joist sit on a stud, so you could consider sistering the studs also. 2x4s are cheap.

My 2x12x24 joists:

I did some old shed saving here:
http://www.garagejournal.com/forum/showthread.php?t=41042

Nice! We don't have McCoy's anywhere around here. We have an 84 lumber in town. I'm going to call them at lunch today. If Lowes/84 don't have them then I'll have to see what's in Lexington (about 30 min away). I'm sure there are some more yards up there.

 

[MN4x4]

If you have a Menards. check out their prices:

24' 4/12 Residential Truss Available Immediately
$47.99

You might not be able to find a 24' 2x10 or 2x12 for that price? And even if you did, how are you gonna get them up there? You can't angle then in from below and still have adequate bearing area, so you're gonna have to take off some of your existing roof near the eave on at least one side to 'sneak' them in.

If you're that far into it, why not just replace the trusses?

 

[davidfite1978]

If you have a Menards. check out their prices:

24' 4/12 Residential Truss Available Immediately
$47.99

You might not be able to find a 24' 2x10 or 2x12 for that price? And even if you did, how are you gonna get them up there? You can't angle then in from below and still have adequate bearing area, so you're gonna have to take off some of your existing roof near the eave on at least one side to 'sneak' them in.

If you're that far into it, why not just replace the trusses?

I hadn't really figured out how to get them up there yet. You don't think with angling each end there's not enough room to sneak it up in there?

It's got a brand new roof on it so I don't want to tear anything off. I don't have to do anything to it, I would just like to have some options. If I can't fit the 24' pieces up there, then maybe I can rebuild the trusses like one of the earlier suggestions. Probably a hell of a lot cheaper.

 

[davidfite1978]

Oh, and I just called 84 Lumber, they have 2x12x24 in stock - $50 each. So around 850-900 bucks. Definitely can't do that this year with all the other remodel going on, but still would like to figure out the best option.

 

[Jim Riseborough]

Davidfite1978,
I am a structural engineer, and what you have is definitely hand made. Most regular trusses have diagonals, not just vertical members, and the bottom chord of the truss is usually continuous, since its always in tension.

If you had rafters, and they added this, then the roof would need a ridge beam to resist the thrust, and thus the load at the ridge would be transferred down to the endwalls, and usually have a beefed up column at the ends, and I dont see that either.

So, if you remove it all, it may collapse. If you dont, and it snows heavily, it may collapse.

I highly doubt any structural engineer would want to tackle that for fixing, It would more be just tear it off, and replace with trusses, or a rafter system with cross joists.

Another option is the I joists (search menards) they are about 35$ a piece. They could be placed to create a ceiling, and they could support the roof a bit more. (i doubt the 2x4 rafters at 2'-0" are structurally adequate). Some connection details would need to be figured out.


Thats general suggestions. Basing this all on the one picture, I could be way off.

As for free advice, there is a time and place for everything. I get calls asking questions, and I tell most that without a site visit, I cant comment. Some pay, some dont and I suppose find someone that will tell them what they want to hear over the phone. Engineering is not a commodity that is discounted, or given out for free. Advice is different.

 

[davidfite1978]

Davidfite1978,
I am a structural engineer, and what you have is definitely hand made. Most regular trusses have diagonals, not just vertical members, and the bottom chord of the truss is usually continuous, since its always in tension.

If you had rafters, and they added this, then the roof would need a ridge beam to resist the thrust, and thus the load at the ridge would be transferred down to the endwalls, and usually have a beefed up column at the ends, and I dont see that either.

So, if you remove it all, it may collapse. If you dont, and it snows heavily, it may collapse.

I highly doubt any structural engineer would want to tackle that for fixing, It would more be just tear it off, and replace with trusses, or a rafter system with cross joists.

Another option is the I joists (search menards) they are about 35$ a piece. They could be placed to create a ceiling, and they could support the roof a bit more. (i doubt the 2x4 rafters at 2'-0" are structurally adequate). Some connection details would need to be figured out.


Thats general suggestions. Basing this all on the one picture, I could be way off.

As for free advice, there is a time and place for everything. I get calls asking questions, and I tell most that without a site visit, I cant comment. Some pay, some dont and I suppose find someone that will tell them what they want to hear over the phone. Engineering is not a commodity that is discounted, or given out for free. Advice is different.

Jim

Thanks for the comments. Unfortunately we don't have a Menard's either. I always find stuff on their site I want that no one around here carries.

I understand what you're saying. It's just hard for my brain to get past the fact that it's stood for 30+ years as-is (with carpenter ant damage too...). I haven't done the measurements but what about this for another option...
I could put 1 post in the middle of the room and connect some 2x12x16's (2 or 3 glued/screwed to make a big beam) going the other direction (across the joists), and then have a more manageable span on either side of the beam to re-do the joists (2x12x12 on either side). then after that's done, use those joists and work up to the rafters with a new truss system piece-by-piece?

I dunno. Just thinking out loud and trying to come up with every option.

 

[Jim Riseborough]

The best analogy I can come up with is that is like putting brand new rims and tires on a rusty old car. Might look better, but long run not solving any problems other than getting you around until the tires wear down.

 

[sands35]

Trusses might be cheaper than a 2x12x24 - but then new trusses imply new shingles and all the other stuff to make it water tight - likely including permits and inspections.

I guess you could price out the required number of shingles and see what that is. Felt and the trim is pretty cheap relatively. OSB is around $8 a sheet now. Also need to pay for a dumperster for disposal of the old roof and it'll cost you a few pizzas and a couple cases of beer to hire some buddies.

 

[Casey69]

tearing out those existing "trusses" would be a big job, but the right way to go. those things look awful.

that said, if funds & time were tight, i'd probably sister on a joist to those trusses & connect them to the rafters on each side of the garage like the poster mentioned above. i doubt that configuration would be engineered to support a 24" span, but it'd probably be much stronger than what you're working with now.

***not an engineer***

 

[buddyboy]

well one good thing, it's been holding up well for a long time!

you could do the following.

working on one at a time, using temp supports on either side of the truss you're working on at the moment.

take down the bottom chord and vertical 'supports'

re-use lumber and build it with plywood gussets similar to this:

glue and nail those gussets

keep your new work level and plumb

might not be the best way, but it's cheap and at least a little safer than what you have now

 

[Bib Overalls]

well one good thing, it's been holding up well for a long time!

you could do the following.

working on one at a time, using temp supports on either side of the truss you're working on at the moment.

take down the bottom chord and vertical 'supports'

re-use lumber and build it with plywood gussets similar to this:

glue and nail those gussets

keep your new work level and plumb

might not be the best way, but it's cheap and at least a little safer than what you have now

I agree. You have all the components of an engineered truss. They are just arranged wrong. At one time the USDA had truss plans on-line. I can't find them on the USDA web site but Googling "USDA Truss Plans" will bring up a lot of information and plans hosted on other sites.

 

[Falcon67]

Dang - prices are up. I paid $1/ft for my 2x12s in 2011.

 

[Daniel Dudley]

Oh, and I just called 84 Lumber, they have 2x12x24 in stock - $50 each. So around 850-900 bucks. Definitely can't do that this year with all the other remodel going on, but still would like to figure out the best option.

Put a 2x6 collar tie halfway up the rafters. Tie it into everything else and you will be OK. Re nail and gusset the bottom cord.

 

[bczygan]

Jim

Thanks for the comments. Unfortunately we don't have a Menard's either. I always find stuff on their site I want that no one around here carries.

I understand what you're saying. It's just hard for my brain to get past the fact that it's stood for 30+ years as-is (with carpenter ant damage too...). I haven't done the measurements but what about this for another option...
I could put 1 post in the middle of the room and connect some 2x12x16's (2 or 3 glued/screwed to make a big beam) going the other direction (across the joists), and then have a more manageable span on either side of the beam to re-do the joists (2x12x12 on either side). then after that's done, use those joists and work up to the rafters with a new truss system piece-by-piece?

I dunno. Just thinking out loud and trying to come up with every option.

Jim Riseborough's comments are spot on.

Your comment about the structure standing for 30 plus years needs addressing.
There are plenty of structures like that. Most garages built back in the day are similar. They were built based on common practice. Like the European cathedrals, they were built strong enough to not fall down, mostly by trial and error.
When something is built that way, there is no way to accurately tell it's capability for additional loads, without reverse engineering it.
The purpose of engineering is to be able to calculate, and know for certain, what a structure is capable of. In this case, you can't know without analysis and calculations. You also can't know what to do to renovate it for the purposes you outlined, without doing the same analysis of the existing and proposed modifications.

Generally speaking, as has been mentioned, the rafters, vertical supports and horizontal joist members form a structure that holds itself up, but there is no way to tell what additional forces it will sustain without either excessive deflection or failure.

The suggestion to install new horizontal members for ceiling joists is workable. The most cost effective would probably be, like Jim said, a wood I beam type joist, especially for that span.

The problem is that the existing structure probably deflects too much already, and will interfere with the new ceiling by hanging too low. Using the existing horizontal members for a new drywall ceiling in conjunction with the new members would not be good because they will have different properties and cause nail pops or worse. Your new ceiling structure should be independent of the existing framing.

Then you need to look at the existing structure as determine of the rafters are adequate for your new roof and local conditions. Is the new roof one layer? What was the roof before that? You say it's dimensional. Was it 3 tab before? They are lighter. You may have already added additional loads to the structure.

You may need to restructure the existing structure to support the additional loads, to make the rafters adequate and to raise the bottom members to clear the new ceiling.

Another method to keep the new and old separate would be to have the new ceiling just below the existing framing, either by a drop of the bottom chord of the new ceiling joists, or by adding a system of spacers and nailers to the bottom of the new joists.

Do you understand what I am saying? Email me your phone.

Bill

 

[bczygan]

Just a note to expand on the "It's been standing for "X" years thing, for everyone who doesn't understand.

Buildings and structures are subject to more that the forces created by their own weight. Wind, rain and snow can act alone or in concert and from different directions, and in not uniform ways. This can place dynamic loads on parts of a structure.

In addition, new materials can add loads the structure wasn't designed for. Roofs that were lightweight metal with no deck under them, that are replaced with wood decking and shingles will change the loads. More commonly, adding new shingles over old, will greatly increase loads. Even changing from a light 3 tab to a heavy dimensional shingle will add weight and corresponding loads onto a structure. Using attic space for storage, adding a ceiling or even lighting, all adds to the demands placed on the structure.

I live in a city that has major portions built for industrial workers and their families from the early 1900's to the 1950's. Virtually every garage was structured in such a way that little leeway was left for any of these additional loads.
When you couple that with inadequate and shifting foundations and rotting sill plates, you have a recipe for disaster. Especially true if new owners don't understand the mechanics involved and don't keep up with maintenance.

These structures were designed by the common practices method. Modern design and engineering involves calculating all reasonable possible future forces that a structure might sustain. Wind, snow, rain, flood and fire, and potential loads the owner might subject it to. All are determined by engineering it to certain standards that are far more robust than it is likely to see.

So the OP has a range of choices, from temporary fix to substantial improvement.

 

[Falcon67]

Put a 2x6 collar tie halfway up the rafters. Tie it into everything else and you will be OK. Re nail and gusset the bottom cord.

No, do not do this. This increases by far the load on the rafters and top plates.

http://mathscinotes.wordpress.com/2010/11/29/the-mathematics-of-rafter-and-collar-ties/

 

[bczygan]

No, do not do this. This increases by far the load on the rafters and top plates.

http://mathscinotes.wordpress.com/2010/11/29/the-mathematics-of-rafter-and-collar-ties/

Very interesting.

I learned a lot!

Thank You!

 

[BearsFan315]

Wow, lots of Good Info on this one here...
sad thing is that looks just like the "truss" in my garage. Talking with my neighbors our garage was built in the 70's using lumber from an old warehouse they tore down in old town. they built our garage from that warehouse, all wood is TRUE 2"x4" Aged Pine (Hard as Rock, Tough as Stone). Yet the Support system, as I call it, looks very much like the pictures posted.
my current plan is to tear down the existing garage and have a new one built in the near future, however, if I am unable to do so I may employ the idea of rebuilding the support system into a truss system.

 

[davidfite1978]

Wow, lots of Good Info on this one here...
sad thing is that looks just like the "truss" in my garage. Talking with my neighbors our garage was built in the 70's using lumber from an old warehouse they tore down in old town. they built our garage from that warehouse, all wood is TRUE 2"x4" Aged Pine (Hard as Rock, Tough as Stone). Yet the Support system, as I call it, looks very much like the pictures posted.
my current plan is to tear down the existing garage and have a new one built in the near future, however, if I am unable to do so I may employ the idea of rebuilding the support system into a truss system.

Nice to hear someone else with a similar dilemma. Unfortunately I don't have the time or money to tear down and start over. Already too far invested in what I have in progress. Just gotta keep chipping away...