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Adding 2nd floor to orginal 2 story open room

26011 Views 13 Replies 7 Participants Last post by  naptown CR
I've spent more time with new construction so i haven't run into a situation such as this yet. The scinario is at my personal home, so i'm not too worried about anyone poking around with anything. I have an addition that was added by my father 20 years or so ago. Its a 24x28 2 story addition to the side of a raised ranch. The rear half of the addition has an office on the bottom and a family room above it. The front half of the addition is a 2 story room with cathedral ceilings throughout. There is a staircase in the center of the room parallel with the floor above.

What i am looking to do is continue the floor all the way across to utilize the space. The current cieling is over 20' tall and could very well be 2 rooms instead. I want to build a wall next to the stairs to support the floor. This gives a 5' or so walkway to the continuing floor which is fine for me. On the oposite side of the wall however is the original gable wall (full of windows) that was framed with 16' lumber. I feel the best course of action is to nail on a ledger board and use joist hangers for the floor joist. My common span is 12' with a bumper out section to span 14'. I will be using 9.5" i-joist material not just for the load (pool table above) but also because they are nice and light and i work alone.

I realize that ledger boards are a normal aspect of construction... anyone who had a deck has one really. My deck was framed 2x8 joist with a ledger board and has all 2x decking material. I know they can support thousands of pounds... but I'm not sure how comfortable i am using a ledger board to support a 2nd floor in my own home. The sq footage of the floor is about 225 and i calculated tributary load at around 6k over the 24' wall span.

I've attached an image to better explain what I'm planning on doing.
Text Line Font Parallel Screenshot

Advice from the seasoned pro's would be much appreciated!!


Thanks in advance,
-- Rick with AHI
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First and foremost, even though it is your house, absolutely consult an engineer to ok everything. Your not talking about a lot of money for them to look it over carefully. My thoughts on the ledger, would be to let it into the wall 1 1/2 inches. This way, it is fully supported, and your not relying on nails to hold up that load. Yes we have all seen decks hanging from a ledger, and yes we have all seen pictures of deck collapses due to improper ledger connections.
I think Warren is one who falls on the side of being over-cautious. This can be done using conventional construction means and not require an engineer's approval.

From what I see of the plan so far.

Andy.
Scorpio: Did u notice he is a first time poster? I think caution should be observed. As far as the ledger, I prefer to notch them in whenever possible. Doesn't really take a lot of time, and helps me sleep better too!:thumbsup:
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Letting in the ledger was a standard practice in balloon framing. The ledger would support the joists on the top, not hangars on the face, though either would work.

I see a much more interesting issue. You say the ceiling is 20' high and is framed with 16' studs. I assume that the other 4' is a foundation for a below grade area, is that correct?

You will need proper foundations along the portion of the new load bearing wall. This may be difficult, or it may be simply breaking out a slab and thickening it. It's possible it was thickened for the stairs, but maybe not. Obviously the new loads will need to be calculated so proper foundations can be engineered. It might be easier to run your joists the long direction. Off hand, I think 14" 350 series would do it, with additional 14" microlams to beef up for the pool table. Better get this properly engineered also.

You will need to add proper fire blocking and deal with window/floor height issues. You will also create new HVAC issues and electrical issues to deal with.
Follow up...

Engineering wise, i know it will be fine. Currently building a 6k sq ft new construction with 14' spans all over and we're using the 9.5" standard 400 series i-joists. I asked about a pool table and the load isn't an issue. I've considered using conventional lumber... but i just framed a 46x28 hip last week and those 22' common rafters are starting to catch up to me... they are definitely a lot heavier to install yourself :no:

I like the idea of letting in the ledger board. While we own several turn of the century buildings, its not something I've seen before. This would definitely work on the two side walls. The main front wall that has the window has a 2' space above it then another 10' wide window. There is no header in there, being a gable wall and all, so i figured i could rip it apart and toss in a header there. Probably tripple 2x12, just to be safe, then hang to that just like the other ledgers. Is letting in a necessary step though? I would think this has to weaken the 2x6 framing at least a little bit.

As far as the floor is concerned... it is a 5" avg thickness slab. Pretty much the same as a garage. People park 10k trucks in them all the time with 4x2500 point loads. I wouldn't see why a short wall with a light (relatively) floor above it would put excess stress on the concrete. There is no roof load or additional load on the floor, its basically floating except for the supporting wall, and with a trib load of 6k over say 25', that's the same as me standing on a single spot on the floor. Its likely not going to have anywhere near a 40plf live load or 20plf dead load on the floor anyhow. My main concern was for the ledger, i wasn't doubting the concrete at all. Anyone else have concerns regarding the load there?

On a final note... the gable wall doesn't sit on anything more than a 6" high foundation wall... if even that. Might be just slab out in front. By 20' tall ceiling... the walls are actually 16' + the cathedral add the height to around 20 or so. We have exposed collar ties with a full cathedral, not scissor trusses.
I think Warren is one who falls on the side of being over-cautious. This can be done using conventional construction means and not require an engineer's approval.

From what I see of the plan so far.

Andy.
I agree with Andy. However nailing a ledger imho is taboo. I would at minimum remove the drywall where the ledger will attach. Install solid blocking if there is nonepreferrably sitting on the plates below. Consider installing a header across where the window bumps out. This would reduce longest span to 12 feet. Was the existng wall balloon framed? if not maybe matching the existing 2nd floor joists and setting them on plates within the wall may make more sense. To really make a good determination we will need to know how the tall wall is framed.
The walls were framed tall and not one on top of another. I thought about throwing a flush beam across the window bump out to reduce the span, but i didn't think that 14' was too much to span.
The walls were framed tall and not one on top of another. I thought about throwing a flush beam across the window bump out to reduce the span, but i didn't think that 14' was too much to span.
My thought there was to eliminate cutting in and installing a header above the lower window. spans are OK Whaqt is the ixisting 2nd floor area framed with?
In any case, the point of connection needs to be fire-stopped between floors. Another option to eliminate the ledger would be to set your joists on jack studs in the wall, running the joists to bear fully on the jacks. The firestops can be incorporated into the assembly also. Where headers may interfere, you can lag bolt the ledger and hanger the joists in those areas. This would eliminate the notching and possible weakening of the studs and give you peace of mind having solid bearing for the joists.
Fire stopping should have occurred somewhere in that wall anyway. Well maybe
Fire stopping should have occurred somewhere in that wall anyway. Well maybe
Possibly, but not likely to fall in an acceptable location.
You don't weaken when you notch,
because you fill the notch with wood.
(Obviously this doesn't apply to
notching the bottom of a joist, though
it does on top)
You don't weaken when you notch,
because you fill the notch with wood.
(Obviously this doesn't apply to
notching the bottom of a joist, though
it does on top)
In this case I agree notching would have no impact on the structure of the wall. It was framed with 2x6 because of the unsupported height. By adding the intermediate deck this will more than make up for any notching.
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