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Gaby – What are you using across that section of the structure where there are no floor joists to keep the walls from spreading from the weight of the rafters and roof?
Ralph
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Oops, sorry, didn't see your second pic with the parallams. But, consider this idea for floor joist support: Build your stud walls continuous to the double top plate and instead of using hangars for your joists attached to a let-in at the same level, drop your let-in down 14 inches, the depth of your TJI, and allow the TJI to run long over the ledger thus created. If you run this let in the entire 30 feet you now have a place to add new floor joists at a future date. You'll see that the position of your floor is not changed, just the method of attachment. Also, with the TJI's run long, if you are concerned that the let-in will not be strong enough to support the TJI, blocking in the end of the TJI will allow you to bolt the joist to the 2x6 stud. Comments? Ralph
*And, your let-in doesn't have to be a 2x12. I think the shear strength of a 2x6 should be more than enough to hold those floor joists. If you also solid block the upper and lower chord of the joists with a 2x6 (laid flat)that goes to the opposing stud the usual band joist is superfluous. (Those bolts I mentioned earlier are probably overkill, too). Comments? Ralph
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Hi Ralph
Thanks for the reply.I deleted my previous reply because I rambled.I like your idea but I don't quite understand how I can add the joists later.If the joists sit on the let-in, they have to be longer than the inside dimension between the walls plus a little extra to protrude past the edge of the 2x6.If the joist is longer than the inside width of the garage, how can I put it in into postion.I can't drop it in from the top because of the cap plates and I can't slide it up from the bottom because of the 2x6 let-in.Can I bend them side ways a bit to pop them in?.I not sure if I explained this clearly.Any comments?Thanks
Gaby
*Gaby, I think the plan checker might want to see vented blocking at detail A between the TJI's. This is in order to transfer shear forces from the roor diaphragm to the walls. Also TJI's need blocking at each location where they are supported by beams. DH
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Gaby - Since the let-ins without joists have no load bearing duties they can be temporarily screwed in place (so you don't lose them) then, when it is time for more floor, remove the let-ins, lift the TJI's into place under the double top plate (you can use temporary shoring to hold them up or screw a tempory bearing block to the outside of the 2x6 stud) and then replace the let-ins, this time attaching them securely. Block and bolt as before and you're done. I'm assuming, I hope correctly, that the inside of your garage will be unfinished with exposed studs. Does this help? Ralph
*Gaby - I have the technology but not the ability to use it yet to send a drawing of what I described. Also, I agree with whoever said NOT to notch your TJI rafters. There are nice steel products that provide a secure seat on the top plate for those rafters which for for best load transferring capacity should be directly over the stud. I don't know what the code is for tieing everything together in your neck of the woods but here in Florida we can expect to use a jillion pounds of strapping from the ridge to the bottom plate and j-bolts to China in the foundation. The 2x6 flat blocking at the top and bottom chord, sandwiching the TJI joists between the 2x6 studs, obviates the need for a rim joist. Ralph
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RALPH
DUDE.. THAT IS GENIUS!!!
I know exactly what you mean.The garage walls will be insulated and covered but I can work around the upper section.I'm working your idea into my plan now.Thank you immensely.
Gaby
*RalphI'm in the process of talking to the guys at the joist company about different hangers and supports that are available.Advice well taken.I can help you with posting pictures or sketches.Let me know what type of program you haveto create line drawings.I use Autocad R14.Almost anything will work.It's just a matter of exporting the file into a .gif or .tif format.If you're interested and you want more explanation, send me an E-mail and let me know which program you can use.I can work up a procedure for you.Thanks again.Gaby
*Gaby,After a quick glance at the posts on this thread I have decided to jump in. For some reason I haven't been able to print your drawing out yet, but I will. I built my house 4 yrs ago, and made plenty of mistakes. However in the process I have learned a lot and would love to share some of it.First Off I also built a gambrel structure. I used glu-lam beam trusses, spaced 8' on center. the connections were done with 1/4" steel plates bolted thru with 3/4" bolts. The beams are exposed to the living area, similar to a timber frame. I used purlins on the roof similar to a pole barn system. I did have a problem with the walls skewing outward at the open area ( the area with no floor ) which I fixed by using a 1" threaded rod spaning the entire distance, with a turn buckle in the middle. I realize that this might seem hokey to some, but for the mountain cabin feel it works. I'm open to suggestions tho.P.s. I have a great article on how to get r-40 in a 9"1/2 vaulted ceiling. I can scan it but I might need some help on how to send it.Rob
*Hi Rob,I would really appreciate any info you can send me.Even though it's going to be my garage, I'm also going for that post and beam look .It wont look like your run of the mill garage.It's more like a well organized multipurpose workshop/garage/office type of thing.Aesthetics, insulation and functionality are important.I'm new at all this and I won't start construction until I have everything worked out.I do have concerns about the walls spreading where there are no floor joists.Insulation info would be great aswell.You can send your scanned image to me by email.Send it as a file attachement.Your scanning program should have options on what format to save your scanned image.If it's a picture (photograph), select the .jpg file extension option when you save.If it's a black and white sketch or drawing, select the .gif or .tif format for saving.Once you've saved it, send me an email and attach that file to it.You can also post the image onto this site if you'd like others to view it.If you have problems or want more explanation, please send me an E-mail.I could expalin it more in detail.Thanks very much.Gaby
*Gaby,Here it is a R-39.10 using 9"1/2 cavity !!!Rob
*Gaby, thanks for sharing. Looks workable, only spent about 60 seconds reviewing , got to get back to the jobsite... Question ??Are the garage doors a overhead type door.. What are their dimensions... Normal hardware for an overhead door requires 14" clearance. A normal door is 7' high x 9' wide (or 16' wide) I use a 7'6" door if the Owner has racks on their vehicles. Or higher if they need it. You can get low mount hardware, but call an overhead door place & ask what the want for clearance, They'll be glad to quote youon the installation , too !Gotta go.
*Looks good Gaby,A few changes that you might want to look at are:1. Imbeding the ridge beams into the roof for more ceiling height especially the 18 x 3 1/3 inch beams.2. Using a parallam or microlam for the garage door header and double check the size with the ridge beam load.3. Use cellulose with a baffle for insulation. The baffle can be cheap paneling rejects stapled to the TJI flanges giving a 1.5" air channel.Have fun.
*Thanks Jim.I'haven't thought about heating yet but I will look into radiant floor heat.
*Hi Mike.I'm still working on options for the garage door.I'll take your advice a see what the garage door guys can come up with.Thanks
*Hi Ron.I thought about embedding the beams in the TJI's but I didn't know you could cut TJI that way.Can the TJI support itself(and load)on the 3/8" osb web or should I use a support underneath the 2x4 section and nail that support to the side of the beam?I checked with Truss Joist Macmillan about the microlam for the header.They suggested it to me when I had the beams sized but they said two 2x12 would do the job.I'm trying to save $$ where I can.I never thought about cellulose.Good tip.I'll look into it.Thanks very much
*Gaby,You would have to use hangers for the TJIs. I think Simpson has adjustable ones.The cellulose will make a big differance in keeping the room from over heating in the summer if the sun hits the roof compared to fiberglass. Also 24" batts are harder to find than 23". If the batts don't fit, you might as well not bother to insulate. Cellulose also has a higher R value and may allow you to go to an 11 7/8" joist (over R35).Ron
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Hi everyone,
Mike, on your reply to my post on gambrel
framing and insulation you asked me to let you know
when I come up with something. Here it is. I apologize
for not being clearer about my intentions for the garage.
What you thought was a knee wall was actually a 30ft
beam. Any comments?
Joe, I tried your suggestion about I joists for rafters to increase
R value. Take a look.
To everyone else, here is some background.
I decided to attempt this myself because I can’t seem to find architects
or designers that would be willing to provide only framing drawings instead
of a complete package. I suppose a few hours of work is just not worth it.
In any case, I’m designing a gambrel roof type garage with half of a second
floor. The size is 20’x30’ with the second floor spanning 20’x16’ and
no intermediate support. The ridge beam is 84.0” above the second floor
giving me usable space of about 10’x 16’ at a clearance height of 77.0”
at the lowest ceiling point of the 10ft width.
The ground floor stud walls use 10ft 2x6’s trimmed to approx. 9ft and
notched to accept a 2x12 rim joists which will support the 14” TJI used
for the 2nd floor joists. The reason I decided to do it this way is because
I only need the second floor to be 16ft long but I want the option of adding
more floor later. This way, I still get 8ft clearance under the second floor.
Is there another way (easier, more cost effective, etc) to do this?
The roof is constructed using 3 main support beams spanning 30ft and
14” TJI as rafters. I’m able to get R40 with FG insulation and span the entire 30ft with a completely
open second floor. The rafters are supported by the walls and not by the floor.
Is there a better way to do this (trusses?) while maintaining the height (84”
from second floor to bottom of ridge beam), the R value, and the max height
allowed by the city (19ft)?
The beams and floor joists were sized by Truss Joist Macmillan
I’m a mechanical engineer and not an architect so the drawing may look a
little “mechanical” in nature. I would appreciate any comments, opinions on
construction, criticism, jokes, whatever. Please take a look and let me know what
you think. Your input is highly valued. Thanks a million.
Gaby.
*Great job Gaby.My comment is this:Radiant floor tubing in the slab>>>>>>>about 500 bucks. Regardless of whether you are in BC or SC.Enjoy and build!
*Gaby, thanks for sharing. Looks workable, only spent about 60 seconds reviewing , got to get back to the jobsite... Question ??Are the garage doors a overhead type door.. What are their dimensions... Normal hardware for an overhead door requires 14" clearance. A normal door is 7' high x 9' wide (or 16' wide) I use a 7'6" door if the Owner has racks on their vehicles. Or higher if they need it. You can get low mount hardware, but call an overhead door place & ask what the want for clearance, They'll be glad to quote youon the installation , too !Gotta go.
*Looks good Gaby,A few changes that you might want to look at are:1. Imbeding the ridge beams into the roof for more ceiling height especially the 18 x 3 1/3 inch beams.2. Using a parallam or microlam for the garage door header and double check the size with the ridge beam load.3. Use cellulose with a baffle for insulation. The baffle can be cheap paneling rejects stapled to the TJI flanges giving a 1.5" air channel.Have fun.
*Thanks Jim.I'haven't thought about heating yet but I will look into radiant floor heat.
*Hi Mike.I'm still working on options for the garage door.I'll take your advice a see what the garage door guys can come up with.Thanks
*Hi Ron.I thought about embedding the beams in the TJI's but I didn't know you could cut TJI that way.Can the TJI support itself(and load)on the 3/8" osb web or should I use a support underneath the 2x4 section and nail that support to the side of the beam?I checked with Truss Joist Macmillan about the microlam for the header.They suggested it to me when I had the beams sized but they said two 2x12 would do the job.I'm trying to save $$ where I can.I never thought about cellulose.Good tip.I'll look into it.Thanks very much
*Gaby,You would have to use hangers for the TJIs. I think Simpson has adjustable ones.The cellulose will make a big differance in keeping the room from over heating in the summer if the sun hits the roof compared to fiberglass. Also 24" batts are harder to find than 23". If the batts don't fit, you might as well not bother to insulate. Cellulose also has a higher R value and may allow you to go to an 11 7/8" joist (over R35).Ron
*Hi Gaby,Great drawing wished I would have talked to you about six months ago.Looking at this seems very similar to my post will collar beams help but I slit the two lower beams thru a window after the building was framed.My thought it would be much cheaper both laborwise and material wise by using trusses. Yes you will lose some space but is this just for a workshop or the like ? If lot size permits you could gain much more building for the same amount of money spent. The insulation will fit properly you can get gable trusses to do the ends etc. Good Luck
*Blacky,I went back and read a bunch of posts related to yours on collar beams.It made me think.The design is similar and I'm wondering if I'll have a problem with the walls being pushed outwards by the weight of the roof.The walls are held together by the floor joists but only for 16' of the entire 30' length.The only advantage I see is that the upper rafter section is supported entirely by the 3 beams.Loads aree transfered to the slab through the end walls.Any insight on this?The ridge beam is 18"x5 3/4 sized by Truss JoistI did call a company to have some trusses designed with the dimensions for space I need.They came up with something, but it seems "iffy" to me.It's about $800.00 cheaper than my beam design.It has less room and seems to be a "bare bones" approach.Then again I should assume the company knows what they're doing.It's their buisness, right?I'll draw it up and post it later on.I'd like your opinion on it.ThanksGaby
* Gaby,
Joseph Fusco View Image
*I believe that the 18 x 3 x 3/4 parralam beams that are supported with double jack studs at either end need to have this double stud carried all the way to the foundation. In other words, the double 2x12 needs double stud support on each end. Also, it looks loke you are creating a beam pocket in the gable end walls to support the beams with a box built of short 2x6s. A more traditional (and probably stronger) method would probably be to get rid of the box and have a king stud on either side of the jacks. the kings would go up the side of the beams.What tool did you use to draw the plan?
*Hi Joe,The reason I designed the floor joists to sit on hangers and not on the cap plate of the walls is because I didn't want the rafters to sit in the floor joists.The floor is only 16' of the entire 30' length of the structure.After the 16' of floor,the roof rafters have to sit on something.I figured that a single rim joist on the outside could not support the load, so I designed it to sit on the wall for the entire 30' length.This way I can add more floor later.I realize that it's not traditional but I don't want 30' of 2nd floor at the moment.Do you think it's still O.k?ThanksGaby
*Thanks for the reply Matt.The 2x12 header has 3 ply 2x6 support at each end.It's probably not very clear on the plan.I think I know what you mean about the king studs(I'm new to the terminology).I should keep the studs underneath the beam but add two other studs going up the sides on the beam, right?I use AutoCad R14 for my drawings.(I do them at work when no one is looking, shhhhhhh!)Gaby
*Gaby, some things you might consider.You should be able to imbed all the beams in the ceiling. Check out Simpson LSSU hangers with web stiffeners. You should use simpson straps over the top of your TJI rafters at the joints to hold them together regardless of which method used.You said cost is important, you should be able to use TJI 11 7/8" or maybe even 9 1/2" and still get R-30.Your 18" parallams will be plenty strong to hold up your roof. Be sure to run solid wood from the beams down to the foundation as Matt said. The footing should probably be widened/thickened under the middle one. good luck, build it. Jim
*Gaby,I like the rim detail. It supports the 14" TJI bottom well.Ron
* Gaby,
Joseph Fusco View Image
*Joe,I agree with you 100%.However, I think I wasn't clear on my explanation for the reason I decided to use joist hangers.Take a look at the sketch and you'll see what I mean.I would prefer to use the traditional method of supporting the floor joists but the sketch should illustrate why I can't.If you can come up with a solution to my problem, I would really appreciate it.The other thing is that if the floor joists were on the walls, the rim joist would have to be 14" wide.Is 2x14 available?(I would rather stay away from microlam..$$$).ThanksGaby
* Gaby,
Joseph Fusco View Image
*JoeI see your point and I agree.What I don't see is a solution.I didn't remove any TJI's from your drawing to prove a point.I'm trying to show that there are no TJI's in that section of the garage.I have a 30 ft long garage which has a second floor for 16 of that 30 ft.The rest is a vaulted ceiling.The rafters will sit on top of the TJI floor joists for only those 16 ft.What happens after that 16 ft when there are no more joists spanning the two walls?How can I support the rafters?I've tried a bunch of stuff but nothing seems to work except joist hangers.Can you suggest anything that would still allow me to add more floor joists spanning the 2 walls, if I decide that I need more room on the second floor in the future?ThanksGaby
* Gaby,
Joseph Fusco View Image
*Gabby,I agree with Fusco that you ought to platform frame for the reasons he stated: compression vs shear bearing and wall spreading... All you need to do is use two stud lengths. The shorter studs go under the floor. The roof sits on the floor where there's floor and on the wall where there's no floor.Also, it appears in your drawing that you plan to notch the TJI's. Don't do that. Contact your supplier to get alternative framing details.I like the idea of recessing the beams and hanging the rafters from them too.Dan
*Gaby - What are you using across that section of the structure where there are no floor joists to keep the walls from spreading from the weight of the rafters and roof?Ralph