Connecting Joists over Bearing Wall
Usually I overlap my joists and block them over a bearing wall but in this case I need the Joists to be the exactly across from each other where they bear on the plates. This is because the rafters will be connected to the joist ends. My problem: With out overlaping, can I butt the joists together over the bearing wall and use plywood plates or Simpson plates? Should I use a 6″ wall v. 4″? Should I use a girder and joist-hangers? (rather not if possible) I am an occasional builder. All my own houses so far, this one is for mom. I am not in a position to ask a nearby professional for a few weeks. Any ideas? Thanks
Replies
"Usually I overlap my joists and block them over a bearing wall but in this case I need the Joists to be the exactly across from each other where they bear on the plates. This is because the rafters will be connected to the joist ends. My problem: With out overlaping, can I butt the joists together over the bearing wall and use plywood plates or Simpson plates? Should I use a 6" wall v. 4"? Should I use a girder and joist-hangers? (rather not if possible)"
TDRucker,
Why is that a problem?
You can overlap the ceiling joist. There's no need to butt them at all or any of the above mentioned. One rafter will be on one side of the center of the mark and the other rafter will be on the other side of the center of the mark on the outside walls and at the ridge. The rafters don't have to butt at the ridge.
I assume the span is to big to get ceiling joist long enough in one piece.
Thanks for the info. I was led to believe that the rafters had to meet at the ridge. Our local inspection has a handout that lists their requirements and one othe things it noted was a nailing diagram of rafters where they meet the ridge. I will find out more. following your diagram, what is the technique when you get to the gable ends? Sorry for the cluelessness but I have always had a wall to frame to and not rafters forming the upstairs.
Thanks again.
TR
Thanks again for the info. I have been going back over posts and it seems like quite a few guys have this same question, From what I read from you and others it is no problem to have the rafters offset on the ridge if your ridgeboard is not 1x material. I'm uncomfortable with "fudging over the distance" as a few suggested. It is just my nature to want it square. Even if I'm the only one that knows. I guess I will use a 2x12 with my 2x10 rafters and call it good.
Terence
"From what I read from you and others it is no problem to have the rafters offset on the ridge if your ridgeboard is not 1x material.I'm uncomfortable with "fudging over the distance" as a few suggested. It is just my nature to want it square. Even if I'm the only one that knows."Your rafters are square. It's sounds like to me that you think that they're offset just at the top and they're not square but they are square. You have the same measurement at the top as you do on the bottom.If the first layout number is 15-1/4" the rafter on the right side of the drawing would be on the right side of the mark on the wall and at the ridge and the rafter on the left side of the drawing would be on the left side of the mark on the wall and at the ridge.As for the last ceiling joists at the the gable end you just butt those together and nail them into the gable studs.You said that you have 2x10 rafters and you will use a 2x12 ridge. How come your making the decision on what size ridge to use? Don't you have a set of plans to tell you?Joe Carola
Edited 10/3/2005 7:03 am ET by Framer
I worked for a guy who put a joist on either side of the line at the bearing wall and kept the rafters the same at the ridge. I never liked doing it but it worked,(just O.K.) But what about the original question, I have pondered that many times myself.Just another homeowner...
petey...couple things
first, butting them is fine.. and they can USUALLY buttover a 2x4 wall.. extra loads might require a 2x6 wall
as to lapping the joists , that 's fine too, and it doesn't matter if the rafters on one side of the house are on one side of the joists and on the other side of the joists on the other side of the house..
the joists wind up 3" offset over the width of the house... i'd still align them on the ridge... or not....
if you are butting the joists.. you can use a plate to tie or a ledger board plate, or a plywood plate..
also .. the floor plywood can tie the joists..
it's important to tie the joists so you can form the third side of the triangle..
the joists tie one side of the house to the other side
in high wind design areas , you now have to strap one set of joists to the opposite set over the ridge, so aligning the joists at the ridge is called forMike Smith Rhode Island : Design / Build / Repair / Restore
"the joists wind up 3" offset over the width of the house... i'd still align them on the ridge... or not..."How are the ceiling joists 3" offset?Joe Carola
must have been late, joe...it 's the rafters that offset 3" , not the joists, the joists are on layoutMike Smith Rhode Island : Design / Build / Repair / Restore
"must have been late, joe...it 's the rafters that offset 3" , not the joists, the joists are on layout"Mike,Still don't get how the ceiling joist or rafter would have a 3" offset. They don't.If you look at the right side of my drawing and you were to hook your tape from the corner and pull 15-1/4" you mark the ceiling joist towards the corner and the rafter away. On the other side you pull your tape from the corner and mark 15-1/4" and your ceiling joist away and your rafter towards the corner. That's all. Nothing offsets 3".One side the ceiling joists and rafters are 1-1/2" one way and the other side ceiling joists and rafters are 1-1/2" the other way.Joe Carola
Edited 10/4/2005 9:06 am ET by Framer
true , joe.. but what we usually run into is the "ceiling" joists are "floor " joists and i like to Butt them so i have no jog in my joist layout..
if you butt your joists you can run your rafters to all on one side or on one side at one eave and the other side at the other eave ( 3" offset )
or you can cut your roof sheathing and get everything back to same-same on 16" OC rafters..
anyways.. the original post is much ado about nothing
Mike Smith Rhode Island : Design / Build / Repair / Restore
"true , joe.. but what we usually run into is the "ceiling" joists are "floor " joists and i like to Butt them so i have no jog in my joist layout."I agree that ceiling joist are floor joist in ceratin houses. Sometimes the ceiling joist are floor joist when the attic is finished. So every house or addition that you frame if you have a center partition you butt the joists only because of the jog?Just curious if you do that for plywood reasons. Joe Carola
i just found that it didn't take much more work to butt them and it kept the plywood even without nailers
it also made it easier to run utilities since we don't get squeezed over the bearing walls (14 1/2 " instead of 13" )
this is really important if you are doing staple-up RFH and a couple other examplesMike Smith Rhode Island : Design / Build / Repair / Restore
I didn't mean to scare such a hornets nest with my simple framing question but it seems that your solution is best to my situation. The ceiling joists ARE the floor joists for a daylight attic and I should have said so. I like the idea of butting the joists together in this case just for the reasons you specified. I think I will expand the wall to a 2x6 as the joists are 2x12 that span 14' and there could be a load on them if we put a seperate apartment upstairs. As you can tell I'm designing this myself and so far the calcs are good but I am always conservative. Just comes from living in earthquake country I guess.
thanks for the posts.
Terence
"I didn't mean to scare such a hornets nest with my simple framing question but it seems that your solution is best to my situation. The ceiling joists ARE the floor joists for a daylight attic and I should have said so. I like the idea of butting the joists together in this case just for the reasons you specified."All I'm trying to say whether it's a ceiling joist or floor joist you do not need to butt them. There is no need for all the extra work. Running the floor joist along side each other is done every day with no problems. I've never once seen any framer butt the floor joists before except one guy and he wasn't a framer. If Mike wants to do that he can but there's no need to ( no offense to Mike) because it doesn't effect anything as far as mechanical/utilities. There's thousands and thousands of house and additions built every day without butting floor joists.With I-joist you can get such long lengths so that you don't need to run them along side each other but even with them there's times when the spans are so long that you run them along side each other and that doesn't create problems. Yes the distance in between is smaller but not enough where you can't get mechanicals in.Theres' many many house framed with 12" centers with joist running along side each other.You said it yourself about a simple framing question and it is. I'm not being sarcastic with that. It's just that you are are making a lot more work for yourself for no reason at all. The only thing you have to do is add a nailer when the sheathing crosses over and that's it.You asked a question whether it was a simple one or not and it is a good question. The answer is a very is a simple one which I have given you one and also Mike has given one. You can choose which ever one makes you feel comfortable.Good Luck.Joe Carola
Instead of adding nailers, how about running a row of blocking (13" blocks) right down the centerline of the top plates of the wall below? Then lay the subfloor with an edge on this blocking. You'd be able to let the perpendicular edges of the subfloor be offset by 1 1/2", eliminating the need for nailers.
One suggestion if you do it this way: Relieve the tops of the tails of the joists, the part that extends past the wall. Just hit them with a coarse belt on a belt sander. That way downward deflection of the joist on one side won't lever up the subfloor on the other, creating a hump.
-- J.S.
John,I never cut floor joist until after they're nailed in unless I have joists going in between girders or a box. I just lay the uncut joist down in places and nail them up. Where the joists run along side each other and extend past the center partition or girder I just eyeball the cut down with my saw and cut the extra off to within about 1-1/2" of the center partition or girder. No need for any belt sander. As far as the blocking there's no need for that either because you start your decking on the outside wall and wherever it hits the change you put the nailer in. It's that simple. You only need a nailer at 8'. Sometimes the end of the sheet lands before the change and sometimes you need the nailer after the change.Do you butt all your floor joist and ceiling joist when you frame?Joe Carola
> Do you butt all your floor joist and ceiling joist when you frame?
No, I've been letting the wild ends run 6 - 16" past the bearing wall. It leaves plenty of room to nail the joists from the two sides together. Grampa did it that way back before there were skil saws. It wasn't worth anyone's labor back then to hand saw the wild ends off. Today, I'll cut them if the offcut would be big enough to use for blocking. Here in earthquake country, we probably do more blocking that elsewhere.
-- J.S.
John, it might not be a really good idea to run the joist that far past the bearing walls. In Michigan, we are limited to half the height of the joist so a 2x10 can only be run past 4.125".
The reason has to do with deflection. When the opposing joist deflects downward, it causes a lifting motion on the cantilevered portion and this can work the plywwood loose and cause squeaking.
I don't think it really will cause much of a problem and someone could argue that a long overlap helps to decrease the span on the lapped joist. Either way, I'm not losing any sleep. Carry on.
jimfka (formerly known as) blue
"With out overlapping, can I butt the joists together over the bearing wall and use plywood plates or Simpson plates? Should I use a 6" wall v. 4"? Should I use a girder and joist-hangers?"Petey,Those are TDRuckers original questions. He can do all the above but it's all just a waste of time and just extra work for nothing. Overlapping the joists at the bearing wall and the rafters not butting at the ridge the way I've drawn it for him is one of the most basic parts of framing."I worked for a guy who put a joist on either side of the line at the bearing wall and kept the rafters the same at the ridge. I never liked doing it but it worked,(just O.K.)"That makes no sense at all to do that. That's what throws the rafters off out of square 1-1/2". Why would anyone even do something so stupid like that? I've never once heard anyone say that the rafters being on either side of the line was a problem and that they had to butt each other before until I read it hear.If people think that they have to butt the rafters at the ridge and can't get ceiling joists long enough then they can butt the ceiling joist together or do all that extra work for nothing.Joe Carola