Adding ceiling/floor in two story living room

tnorton · 01-23-2010, 09:27 AM

I have a two story livingroom. I want to put a ceiling/floor to make a gameroom upstairs . I have 2 2x12 to tie into. A friend of mine said I should use wood or osb Ibeams for stregnth and ease of installation. The size of the room is 17x19 and I plan to run the beams across the 17ft span. I initially planned to tie the beams into the 2x12s with brackets but my friend said I should remove the sheetrock above the existing 2x12s and install the beams on top of the 2x12s. It seems that this would be stronger but I have never worked with Ibeams and would like to know if there are special brackets for this installation and what size beams I should use. I found out they make a 10" and a 12" beam. If I am able to use the 10" I can keep the 9ft cielings downstairs and upstairs. If i have to use the 12" then I would have to have a step up for the upstairs into the room and would make the ceiling upstairs less than 9ft. Do you have any suggestions as to which size beams I should use and the installation of the beams on top of the existing 2x12s, is that the correct way to install. I live in Wake Forest, NC. if that helps in any way as far as code goes. Thanks, Tony

vsheetz · 01-23-2010, 10:08 AM

There was a thread awhile back with similar topic and senario - have you tried to search?

tpolk · 01-23-2010, 10:12 AM

whats the clear span on 2x12? I dont think it will carry the load as stated. you need to have this professionaly sized

Scuba_Dave · 01-23-2010, 10:47 AM

I-joists you would need to have sized, a lumber yard may be able to do this for you
2x12's will span approx 17' depending upon species & grade of wood

I had my I-joists sized for a 19' span & they spec'd BCI-40's 12" depth
I went the next size stronger - BCI-60, also 12" depth

Having the joist land on top of the beam is preferred

tpolk · 01-23-2010, 10:54 AM

I dont know about the 2x12 dave I have a 16' clear span with just a gable over it and i needed 2- 1-3/4x12 lvl

jlhaslip · 01-23-2010, 11:04 AM

Think scuba dave is talking about the floor joists span and tpolk is talking about the beam carrying one end of the floor joists.
As to the preferred connection method, having the joists on top of the beam is likely easier to layout/install, but using joist hangers will be as strong if the correct hanger is used (properly installed).

Spruce-Pine-Fir #2's or better will go 17 ft as per http://www.awc.org/calculators/span/...Options#answer

You need Select Structural grade to go 19 ft using S-P-F. I-joists would be better. Hangers would cost more using I-joists.

Regards to the beam carrying the load, it would likely need to be strengthened to carry this new added load. Possibly at each end. A Stuctural Engineer inspection would tell you exactly what is required.

Ron6519 · 01-23-2010, 11:05 AM

Quote:

Originally Posted by tnorton

I have a two story livingroom. I want to put a ceiling/floor to make a gameroom upstairs . I have 2 2x12 to tie into. A friend of mine said I should use wood or osb Ibeams for stregnth and ease of installation. The size of the room is 17x19 and I plan to run the beams across the 17ft span. I initially planned to tie the beams into the 2x12s with brackets but my friend said I should remove the sheetrock above the existing 2x12s and install the beams on top of the 2x12s. It seems that this would be stronger but I have never worked with Ibeams and would like to know if there are special brackets for this installation and what size beams I should use. I found out they make a 10" and a 12" beam. If I am able to use the 10" I can keep the 9ft cielings downstairs and upstairs. If i have to use the 12" then I would have to have a step up for the upstairs into the room and would make the ceiling upstairs less than 9ft. Do you have any suggestions as to which size beams I should use and the installation of the beams on top of the existing 2x12s, is that the correct way to install. I live in Wake Forest, NC. if that helps in any way as far as code goes. Thanks, Tony

I had a job like this last Fall. Homeowner split a catherdal space into two levels because the pro's estimates were too high. He attached the ledger 1/2" off the wall and attached it with 1/4" lag bolts. He connected the joist hangers to the ledger with 1 5/8" drywall screws. The weight of the floor caused the new french door to bind because of a little bitty header above it.
Lesson to be learned, is to have it engineered correctly and make sure you can execute the plan competantly. If you can't, put the tools down and step away from the project before someone gets hurt.
Ron

tnorton · 01-23-2010, 11:09 AM

Yes, i tried but im new on this site and cant seem to find it at this time. will keep trying. tx, tony

tnorton · 01-23-2010, 11:15 AM

Sorry, im not a carpenter or builder. Not sure what you mean by clear span. If you mean the legnth the Ibeam needs to be I plan on running them on the shorter distance 17ft. The room is 17ftx19ft.

tnorton · 01-23-2010, 11:18 AM

Im trying to keep the cieling height the same and the floor upstairs level. If I use a 10" I can achieve this. Do they make a 10" strong enough to handle that span.

tpolk · 01-23-2010, 11:19 AM

clear span means unsupported distance. the wall with 2x12 will it be an open area unsupported by wall and if so what length is this?

tnorton · 01-23-2010, 11:21 AM

Do they make a 10" beam strong enough to carry that span?

tpolk · 01-23-2010, 11:27 AM

you need to take your info to someone who can do span/load calculations. you dont want to be guessing someone can get hurt. alot of lumber suppliers can run these for you

tnorton · 01-23-2010, 01:05 PM

Thanks for the info, I didnt want to have any supports in the room, so i guess the area that you are asking is the size of the room? 17x19. tx again, tony

Daniel Holzman · 01-23-2010, 01:59 PM

The exact amount a given beam or joist can span depends on the load the element will carry. The North Carolina building code will specify a minimum amount of load that the structural element must support, both dead and live load. However, the specific geometry of your house may cause any given structural element to be subjected to loads not shown in the code book. Frankly, I would be surprised that you could pull a permit without some calculations performed by an engineer, architect or supplier. If you are planning to perform the work without a permit, good luck, be careful, and I hope you know what you are doing. If you are planning to pull a permit, you should check with the local code enforcement official about what they will require in the form of drawings, calculations, and inspections.