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2nd floor beam

14K views 67 replies 7 participants last post by  markharmon 
#1 ·
when you have a 2 story house and obviously the joists can only span so far until you need vertical support. How is that usually constructed for a second floor? I supposed a flush beam and column on the second floor?
 
#9 ·
#10 ·
joists can only span so far. typically there are two ways of supporting the interior ends of floor joists, with a beam or with a load bearing wall. If the choice is a beam then it is usually either flushed framed or dropped under the joists. all loads must be accounted for and brought down to the foundation.
 
#12 ·
for a second story joists do they usually span the entire distance wall to wall with a bearing wall in the middle? Or, for instance, on a show I saw the joists from one end of the rim joist span to a point on a wall plate and then another set of joists were placed right next to the other and then they spanned to the other rim joist. Does this sound correct?
 
#17 · (Edited)
joists can be lapped at the drop beam or load bearing wall, can be connected to a flush framed beam or can be continuous from outside wall to outside wall with either a beam or load bearing wall in between. if the span is 28' for example it would be a special order (in my area) to get solid sawn lumber joists that would span that far, I-joists could easily span that. Depends on what you're using as joists and what the lumber yard can provide. Also the long the solid sawn joist is the HEAVIER and more difficult it is to work with, and the more expense for the material normally.

if you're looking for a cookie cutter recipe that can be followed for every project I'm afraid you're out of luck. books will give you general information, experience and knowledge also come into play. Sometimes you have to make decisions based upon your knowledge and experience that may not match with what the book says.

all beams must transfer their loads to undisturbed natural material or engineered fill. Usually this is either foundation walls or footing that the columns bear upon. Excavation depth depends on the type of soil,and frost protection depth. Footings sometimes need to go past the frost line, depends on if they are outside or inside of the perimeter foundation. If interior usually they do to the same depth as the footings, exterior they will usually go to below the frost protection depth, unless they are close to the foundation walls. if the ground was disturbed from excavation for the perimeter foundation then they would need to go down to where you find undisturbed soils.

Hope this helps.
 
#18 ·
Lets say you need to jack up part of the floor to level it. You would use jack posts with a beam under the joists and attached to the jack post. This is temporary. After the floor is leveled you would install wood columns or lally columns on footings below frost depth to support the beam?
 
#21 ·
This is just a question its not something i need to do. I just would like to get an understand of how a jack post comes into play. The jack posts have to attach to a beam, right? Once you get it leveled you add permanent posts, correct? Are you in favor of lally columns or wood posts? I know wood shouldn't be in contact with concrete though cause of possible moisture issues.
 
#20 ·
It is much better to say exactly what you are trying to do and ask how to do it instead of asking apparently random questions that amount to a framing 101 course. It becomes very frustrating to those trying to help you. Reading up on the basic theory of residential framing will help your confidence level going into a major structural change to your home. Once you understand how the whole thing works it will be easy. Just do the math.
 
#22 ·
As jagans said, this is a forum for others to help you with specific jobs you're currently or planning on doing. You are repeatedly asking questions that would be answered very early on in a framing book. If you have interest in the topic I suggest you do some basic reading and then come back w/ specific questions. Thanks
 
#25 · (Edited)
Want to see some beams? Click on the link in my signature......

Lets see...one of them is an 11.25x5.25 20' long.....another one is 11.25x3.5 18' long....that one sits on top of an existing wall........then I have a couple that are 11.25x7 and about 14' long.....

And then I have my steel beam....6x10 and about 14' long...with some custom buckets on the end made out of 1/4" plate steel....

Here is one of the pics....

 
#28 ·
Want to see some beams? Click on the link in my signature......

Lets see...one of them is an 11.25x5.25 20' long.....another one is 11.25x3.5 18' long....that one sits on top of an existing wall........then I have a couple that are 11.25x7 and about 14' long.....

And then I have my steel beam....6x10 and about 14' long...with some custom buckets on the end made out of 1/4" plate steel....

Here is one of the pics....

Why do you have so many beams? Where are the joists?
 
#30 ·
are you positive the 2nd floor joists do not extend out to the 1st floor walls? my second floor living space is smaller than the first floor, but my 2nd floor joists extend out to the perimeter of the first floor walls. my roof sits on the second floor deck and has a few dormers that creates sufficient space for the bedrooms.

got some photos of your home from the exterior?
 
#32 ·
Im not sure if they extend out. I guess what im asking is do rim joists have to sit on a wall that is foundation supported? So, your second floor joists span the entire length of the first floor? I figured since your upper floor is smaller than first floor then why would the rim joists need to extend all the way around the perimeter of the first floor top plate when part is not going to be used. Do you see what I mean? Since you have a 2 story house do just your load bearing walls support the roof above or are there any beams?
 
#34 ·
my second floor joists are supported by the exterior walls and two (either side of a central hallway) interior load bearing walls (on first floor). roof rafters are supported on exterior walls only. now the issue in my home is the two interior load bearing walls are not supported by a beam, the beam was installed in the middle of the hallway. so I have a hallway that is crowned like a road due to the load from the second floor pushing down on the 1st floor joists, which in turn cause lift on the joist ends over the one beam.

I've got to install two new beams in my basement, but I will not attempt to jack things as my home is a 100 years old with lath and plaster.
 
#38 · (Edited)
ddawg's pics show a 3rd way of supporting the (rim?) joist - on cantilevered
beams.

Let's see if I've got this right - and hopefully he'll correct me if I'm wrong - but I would guess most of the weight is taken by the heavy (LVL?) beam in the foreground. That looks to support the rim joists through that nifty steel connection. In turn, the rim joists tie together the cantilevered ends of the floor joists. Presumably there's a wall going above the rim? There will be a substantial post below the heavy beam, hidden behind the strand board?

Nice job.

PS didn't notice your earlier pics showing the steel beam!
 
#42 ·
You have to excuse the silly smile on my face....I'm a pretty happy camper at this point getting that beam up....but if you look under the steel beam you will see a 6x6 post...that takes the downward force of that section...my foundation below that point is a 4' x 4' pad that is about 3' deep....

Then on the angled wall I have some 4x6 posts under the PSL beams and the foundation in that area is another large pad....



If you click on the link in my signature you will see a lot more pics.
 
#45 ·
It depends on the design or your house. If it is a cape style house there is no rim joist on the second floor. If it is a colonial, there will be a rim (Band) joist on the second floor, and the second floor is often cantileverd out over the first floor exterior wall two feet. It all depends on the style of house it is. See? It all depends.
 
#67 ·
I just had my addition insulated....$1300....done in one day....included insulating the joists between the 1st & 2nd floors....upstairs is all vaulted....addition is a little over 1000 sq ft. Done in one day....and I didn't itch at all from the insulation.....

I figure material costs alone was over $500....3 guys at $150/day each.....company has to make a small profit.....

Yea....not worth my time to do it....

Now to find some drywall guys....
 
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