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Discussion Starter #1
Back in September I asked about a Garage Construction Problem Correction. After some false starts and unavoidable delays I'm finally about ready to re-secure the couple of existing joists/rafter ties that had come loose, add the additional joists/ties, put back the collar ties I'd removed and add additional collar ties. I'll also install hurricane ties where I can.

The existing construction has a cross-tie going across the tops of the front-to-back rafter ties/joists, tied-in to the side of the house , secured to the tops of the front-to-back ties/joists, and secured to one rafter opposite the house. (You can see the ends of it in the 2nd and 3rd photos, below.)

Here's the question: The span on those front-to-back rafter ties/joists is about 23 feet. With the ones I"m adding that's ok if all they'll be used for is ties (tension), but I'd like to place 4x8' sheets of plywood up there for storage. Plus the existing ties/joists had some 1x3's and 1x4's providing some mid-span support for some of the rafters. (You can see some of them the first photo.)

I was thinking maybe replace that cross-tie with a pair of 1-3/4 in. x 9-1/4 in. LVL joists under the front-to-back ties/joists, with flush-mount hangers on 2x8's at each end--secured to several wall studs on the house side and several wall studs on the far side (photos #2 and #3).

Then watch for deflection and, if necessary, a vertical support mid-span, later on.

Is this a reasonable approach?

Photos:

Sorry about this overview photo. It was the best I could achieve.



House wall side.



Far garage wall side.

 

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retired framer
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For 20 ft, the smallest beam we get would be 5 1/2 x 14".

23 ft with somewhat less load is anyone's guess unless the anyone is an engineer.

The header over the window would have to be made bigger, I suspect.
 

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So drew on your pic to better understand, is this correct? You want to store on top of the existing 2x4 rafter ties, so instead of relying on just the 2x4 strongback for "extra" support, you figure if you put a couple LVL under the rafter ties (which will be hung off of ledger board each end) would be better than what you have now anyway? The rafter ties I think are 23' long, but how long will the LVL be, and how much storage you talking about?
 

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Discussion Starter #7 (Edited)
23 ft with somewhat less load is anyone's guess unless the anyone is an engineer.
I guess all I'm looking for is educated guesses. Whether I'm completely off in the weeds or whether this has some likelihood of success.

The header over the window would have to be made bigger, I suspect.
Definitely. I'll be tying 2x8's across both ends. (Two on the house side, because I have to clear that conduit.)

So drew on your pic to better understand, is this correct?
Wow, that's terrific! Yes, exactly.

You want to store on top of the existing 2x4 rafter ties, so instead of relying on just the 2x4 strongback for "extra" support,
They're all 2x6's, and there'll be nearly triple the number there currently are when I'm done. Otherwise: Yes.

That thing I've been calling a "cross-tie" has a name, "strongback," eh? Now I've learned something new. Thanks!

you figure if you put a couple LVL under the rafter ties (which will be hung off of ledger board each end) would be better than what you have now anyway?
Bingo!

The rafter ties I think are 23' long, but how long will the LVL be, and how much storage you talking about?
The LVL will also be 23' long.

How much storage...? Good question. I don't plan to pile it to the roof. And it'll mostly be things like a small artificial Christmas tree (±4' in height), boxes of Christmas ornaments, couple of sports equipment bags (paintball and ice hockey gear) and the like. Have a couple small boxes of spare floor tiles from the bathroom remodels. That's about the heaviest stuff I'd put up there. But I can put those elsewhere, too. The hardware I upgraded from my table saw (stamped steel wings, fence rails, the fence).

Maybe 200-300 lbs. per 4x8 sheet, max? So a total of 800-1200 lbs.?

I could go to 11-1/4" LVL w/o affecting headroom in the garage, but I'd prefer to stick with no more than 9-1/4".
 

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retired framer
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You do not hang a beam from a ledger screwed to studs. You open the wall and install jacks and king studs.

The other end might be hung from a header if the header is big enough. Here all our headers are 2x10 doubles, and are never enough for a beam. At the very least would have to change that o a 2 ply LVL much taller than what is there now and likely it would want 2 jacks under each end.
 

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Attic storage is always tuff to predict. With your username and location, you (or future occupants) might eventually have some iron heads up there or want to hoist an engine from the LVLs. But 10psf is what is normally considered for limited general storage.

I think you're saying you'll use what's there and add some more 2x6 rafter ties to be @24"o.c. And you'll use continuous 24footers or splice 12footers?

Splitting the span of the 2x6 to <12' looks to cover the 10psf up there, but the LVLs should be designed for that considering their length. And you'd have to adequately support the ends like Neal is getting into.

The "strongback" is usually two 2x4 - one flat, one turned to create an 'L.' I've heard "binder" as well, that may be for just a flat one but I don't know if there's a differentiation in terms.
 

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retired framer
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Attic storage is always tuff to predict. With your username and location, you (or future occupants) might eventually have some iron heads up there or want to hoist an engine from the LVLs. But 10psf is what is normally considered for limited general storage.

I think you're saying you'll use what's there and add some more 2x6 rafter ties to be @24"o.c. And you'll use continuous 24footers or splice 12footers?

Splitting the span of the 2x6 to <12' looks to cover the 10psf up there, but the LVLs should be designed for that considering their length. And you'd have to adequately support the ends like Neal is getting into.

The "strongback" is usually two 2x4 - one flat, one turned to create an 'L.' I've heard "binder" as well, that may be for just a flat one but I don't know if there's a differentiation in terms.
A normal strong back is only as strong as the nails down into the joist pull out resistance. To spread a load from above an upright with blocks down in the side of the joist is better as all nails are in shear to the load.
 

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Discussion Starter #11
You do not hang a beam from a ledger screwed to studs. You open the wall and install jacks and king studs.
How about 2-by headers atop side-ways jack studs secured to the existing wall studs? Would that be acceptable? I could easily do that on both ends.

Attic storage is always tuff to predict. With your username and location, you (or future occupants) might eventually have some iron heads up there or want to hoist an engine from the LVLs.
I've occasionally considered a hoist, but not for engine work. I doubt I'll ever do that. I'll leave future occupants to solve that problem for themselves :)

But 10psf is what is normally considered for limited general storage.
"psf" == pounds/sqft? So 320 lbs/sheet of 4x8?

I think you're saying you'll use what's there and add some more 2x6 rafter ties to be @24"o.c. And you'll use continuous 24footers or splice 12footers?
I'm going to try to get the additional 24-footers in there with enough meat on the ends to secure them adequately. (I'm thinking one structural screw and three 3 in. nails with my framing gun.) If that doesn't work, I'll cut 'em in half and re-secure them in the middle with 3/4" ply gussets, screwed and glued, on each side..

Splitting the span of the 2x6 to <12' looks to cover the 10psf up there, but the LVLs should be designed for that considering their length. And you'd have to adequately support the ends like Neal is getting into.
Noted.

Like I said: I'm thinking get it installed, keep an eye on deflection, and, if necessary, install a mid-span post. That will split the LVL to two <12' lengths.

The "strongback" is usually two 2x4 - one flat, one turned to create an 'L.'
Fascinating, because, w/o even being told, I'd looked at the strongback that was in there, thought "that's lame," and had planned to replace it with an L-beam fabricated from glued and screwed 2x6, any way :)

So it's sounding like I'm not completely off in left field, but just need to up my game a bit?

Q: How to hang the LVL off each end? Will face-mounted joist hangers suffice?

Thanks for the help, guys!
 

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How about 2-by headers atop side-ways jack studs secured to the existing wall studs? Would that be acceptable? I could easily do that on both ends

Thanks for the help, guys!
In some garages the concrete curb sticks out from the wall, studs or a post going down to that work.

But just nails, you are on your own, and you would likely want to remove the drywall to get good contact with a stud inside the wall, by then you may as well just add studs to the wall.
 

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Discussion Starter #13
In some garages the concrete curb sticks out from the wall, studs or a post going down to that work.
No certain what you mean. There is no curb on the inside. The concrete is level and flat right up to the wall.

On the house side I cannot remove the drywall. It's the firewall. It has to be there and has to be uninterrupted by code. (As I understand it.)

But just nails, you are on your own, and you would likely want to remove the drywall to get good contact with a stud inside the wall, by then you may as well just add studs to the wall.
Oh, I wouldn't use nails. That's the kind of idiot thing the idiot original owner did. (I have a photo or two somewhere...) Ah, here we go. This is how somebody attached that strongback to a single wall stud on the house side:




Surprise, surprise: The nails pulled out. Imagine that


I'm talking about attaching jack studs, of a sort, and headers, to the existing studs using structural screws. The new/additional studs would go all the way down to the concrete garage floor. My thinking is the jack studs would take the load. The screws to the existing studs just to keep them in-column. A bit of a hack: Yes. But it's only an unfinished garage :)

The bottom foot or so on the house side is actually poured concrete basement wall. I could even secure them to that with 5" spring spikes.

I'd probably want to put a sill on the bottom to keep the end grain of the jack studs from directly contacting the concrete?
 

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No certain what you mean. There is no curb on the inside. The concrete is level and flat right up to the wall.

On the house side I cannot remove the drywall. It's the firewall. It has to be there and has to be uninterrupted by code. (As I understand it.)


Oh, I wouldn't use nails. That's the kind of idiot thing the idiot original owner did. (I have a photo or two somewhere...) Ah, here we go. This is how somebody attached that strongback to a single wall stud on the house side:




Surprise, surprise: The nails pulled out. Imagine that


I'm talking about attaching jack studs, of a sort, and headers, to the existing studs using structural screws. The new/additional studs would go all the way down to the concrete garage floor. My thinking is the jack studs would take the load. The screws to the existing studs just to keep them in-column. A bit of a hack: Yes. But it's only an unfinished garage :)

The bottom foot or so on the house side is actually poured concrete basement wall. I could even secure them to that with 5" spring spikes.

I'd probably want to put a sill on the bottom to keep the end grain of the jack studs from directly contacting the concrete?

By curb I meant the top of the foundation, which is some time visible because it is thicker that the wood wall.



Yes the drywall has to be there, you cut the drywall install beam and studs, replace drywall and seal around the beam.

If you trust the concrete floor to carry a load, put in a post saddle and use a post.



The picture is a beam pocket ready for a beam.
 

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Discussion Starter #15
I thought I'd share with y'all what I finally ended-up doing.

It took a while, but I finally got the walls as plumb as they were going to get. (It was to the point that the ends of two rafter ties that had come loose were butting-up against the roof sheathing.) Most of the wall studs are now plumb and all of them have the bubble between the lines.

I doubled the number of collar ties and more than doubled the number of rafter ties. I was able to get the new rafter ties in, with plenty of overlap with the rafters--at least as much as the originals had, without too much trouble. Collar and rafter ties were secured to the rafters with a 3-1/8 in., #10 GRK structural screw and three 3 in. nails each.

I then installed a 9-1/4 x 3-1/2 in. LVL mid-span beam.



The beam is supported on the house side with two 2x6's, secured to the wall stud behind with 3-1/8 and 4-3/4 in. #10 GRK structural screws. The vertical load is supported primarily by the concrete floor.



On the far side the beam is supported by jack studs and a header formed of doubled-up 2x6's, secured to the wall studs. Again: The vertical force will be primarily supported by the floor.



I created a "pocket" for the window end of the beam by affixing 2x4's to the top of the header, either side of it.




The beam was secured at each end with a pair of 4-3/4 in. #10 GRK structural screws.



I toe-nailed all the rafter ties to the top of the beam with 3 in. nails: One driven from each side.



I removed the old not-so-strong strongback, fabricated a kind of "L-bracket" of glued and screwed 2x6...



...and secured that to the rafter tie to which the old strongback had been attached and to the top of the beam.



Finally, I added support for the ridge board in two places, using a pair of doubled-up 2x4's.



The chains and turnbuckles you see in that photo were part of what I used to pull everything back in. I think I'll just trim off the excess chain and leave them there.

So: Verdict? How did I do?
 

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Discussion Starter #17
Looks good.
Thanks, Neal! Coming from you, I regard that as high praise indeed :)

I realize that 9/1-4 x 3-1/2 in. LVL beam is not optimal for that span, as per your prior comments, but I was height-limited by the space I had over the top of that window. In fact, as you can see from the photos: That 9-1/4 in. beam brought the bottom of the 2x6's exactly to the top of the window frame.

I'll keep an eye on deflection. If I start seeing much, I'll jack it back up and install a center post in the middle of the garage. That'll reduce the span on each side to less than twelve feet.

Side note: Here's a funny ol' thing from the files of "Even a blind squirrel...": Once I got that beam snugly up under the rafter ties and the end supports in, only then did it occur to me to check to see if the beam was level. Doh! Darned if it isn't right on the money.
 

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Thanks, Neal! Coming from you, I regard that as high praise indeed :)

I realize that 9/1-4 x 3-1/2 in. LVL beam is not optimal for that span, as per your prior comments, but I was height-limited by the space I had over the top of that window. In fact, as you can see from the photos: That 9-1/4 in. beam brought the bottom of the 2x6's exactly to the top of the window frame.

I'll keep an eye on deflection. If I start seeing much, I'll jack it back up and install a center post in the middle of the garage. That'll reduce the span on each side to less than twelve feet.

Side note: Here's a funny ol' thing from the files of "Even a blind squirrel...": Once I got that beam snugly up under the rafter ties and the end supports in, only then did it occur to me to check to see if the beam was level. Doh! Darned if it isn't right on the money.
Yeah, it may not be the best but compared to what you had it is far better than nothing.
 

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Per LVL catalogs, the Total load capacity of your 2.0E LVL is about 80 lb. per linear ft. of span, x 23' span = 1840 lb. Subtract out 600 lbs. for the weight of the wall ties that you are supporting, and the remainder is your useful load. So you can safely throw about 50 lbs of payload on each of maybe twelve sheets of plywood, which themselves weigh 48 lbs. each if they are 1/2" thick. Don't concentrate all of your sheets in one area; distribute them evenly across the ceiling and try to avoid the midspan. Accounting for 12 sheets of plywood, your safe useful payload is about 640 lbs. total.
You can double that capacity by doubling up the LVL beam to be 4-ply.
Or add a center post and you quadruple your capacity.
 
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Discussion Starter #20
Wow! Thanks for that useful data, House Designer.

I've got only 3 sheets of 1/2 in. plywood up there. 1-1/2 sheets each side of the beam, the long sides paralleling it, and they're centered about half-way between the front and back walls and the beam.

I doubt I'll be placing as much as 640 lbs. up there.
 
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