Hello,

We want to rennovate the area above our garage to make a bonus room.
Currently, the ceiling joists (soon to be floor joists) are 2x10x20,
spanning the entire width of the garage (about 19' 8") without any
beam. I know that I can install a beam to meet the local code
(Charlotte, NC) but what I don't know is if I can simply sister the
joints instead?

Installing a beam probably costs less in materials but it may take
considerable headroom out of the garage below it.

Thoughts?

In article . com,
wrote:

We want to rennovate the area above our garage to make a bonus room.
Currently, the ceiling joists (soon to be floor joists) are 2x10x20,
spanning the entire width of the garage (about 19' 8") without any
beam. I know that I can install a beam to meet the local code
(Charlotte, NC) but what I don't know is if I can simply sister the
joints instead?

For a room floor, even a 2 x 12 would not go 20 feet. A 2 x 10
is good for maybe 13 to 14 feet if you use top notch lumber
at 16 inch intervals. At 24 inches, you get even less distance.

You might be able to get away with this if you sister every
joist, install new joists 1/2 between every existing one, and
then put in a lot of blocking to keep the joists from twisting.
You may still end up with a bouncy floor.

You really have two good options. One is to get an engineer
to calculate it out for you, or go with the beam. If you get
a steel beam, you can make it a lot thinner than a wood beam,
which might ease your headroom issue. An engineer might be
able to come up with a 3rd option of making your bonus room
structure into a truss that would support the floor joists
from above.

-john-

--
================================================== ====================
John A. Weeks III 952-432-2708
Newave Communications http://www.johnweeks.com
================================================== ====================

Thanks, John.

The 2x10s are spaced 12" o.c. I had done some additional reading - how
about i-Joists? I have a call scheduled with the engineer on Monday
(he originally recommended the beam . . .) to see what other options
might be available. I'm just trying to do some weekend homework.

Cheers,
Chris.

In article ,
says...
In article . com,
wrote:

We want to rennovate the area above our garage to make a bonus room.
Currently, the ceiling joists (soon to be floor joists) are 2x10x20,
spanning the entire width of the garage (about 19' 8") without any
beam. I know that I can install a beam to meet the local code
(Charlotte, NC) but what I don't know is if I can simply sister the
joints instead?

For a room floor, even a 2 x 12 would not go 20 feet. A 2 x 10
is good for maybe 13 to 14 feet if you use top notch lumber
at 16 inch intervals. At 24 inches, you get even less distance.

Of course, a lot tdepends on local code requirements. As a practical
matter, 2x8x16-foot joists on 24" centers make a lively but
structurally sound floor in our hundred-year-old house, even though
there's no way the code would allow that today.

If you can't meet code with wood without the beam, another
alternative to look at is steel framing -- more costly, but if you
really want to avoid the beam and lost headroom, it can work.

--
is Joshua Putnam
http://www.phred.org/~josh/
Braze your own bicycle frames. See
http://www.phred.org/~josh/build/build.html

A flush beam may work and not impact headroom at all. I do not know, off the
top of my head, what size beam or if the 2x10 split in the middle is
sufficient.

A flush beam involves cutting each joist in the middle, wide enough cut to
fit the beam. Of course temp walls will need to be built in the garage to
support the ceiling/floor above. Also, consider what will hold up the beam
at each end. Column maybe? Wall, ideally. If everything is figured correctly
you may be able to get a flush beam in with no columns.


wrote in message
ups.com...
Hello,

We want to rennovate the area above our garage to make a bonus room.
Currently, the ceiling joists (soon to be floor joists) are 2x10x20,
spanning the entire width of the garage (about 19' 8") without any
beam. I know that I can install a beam to meet the local code
(Charlotte, NC) but what I don't know is if I can simply sister the
joints instead?

Installing a beam probably costs less in materials but it may take
considerable headroom out of the garage below it.

Thoughts?

Thought I would give everyone an update. The engineer responded that
the span was just too great and that 2x10 unengineered lumber would
have to be spaced 3" o.c. to meet the load requirements. (Although I
don't know what kind of load that would place on the supporting,
exterior walls!

Anyways, it looks like I'm going with a flush beam. It will be
supported at the garage door end by an upgraded header.

- Support both sides with the temporary walls.
- Notch (or completely cut) space for beam
- Use hangers to secure the floor joists to the hangers
- Remove the temporary walls

My final question - what's the quickest, safest way to build these
temporary walls? Don't laugh, but can I rent them? (I'm thinking of
some adjustable, metal posts and support beams).

Thanks again - kudos to "No" for the "right" answer.

PS: Code office said I could get away with sistering 2x12s but..I'd
rather have the flush beam.

Thanks for the kudos! For your temp walls just get the 2x4s that are on sale
that week and build a wall, on the floor then raise it into place. It should
fit snug but not so tight it puches up the ceiling. No need to remove
sheetrock. You may want to build the wall a couple of feet away from where
you will cut in for your beam so you have room to work. If things are
cramped you may need to bring in the beam before you build the temp walls
otherwise you may not be able to navigate it into the space w/o cutting a
hole in the outside wall!

Good luck.

"Chu" wrote in message
oups.com...
Thought I would give everyone an update. The engineer responded that
the span was just too great and that 2x10 unengineered lumber would
have to be spaced 3" o.c. to meet the load requirements. (Although I
don't know what kind of load that would place on the supporting,
exterior walls!

Anyways, it looks like I'm going with a flush beam. It will be
supported at the garage door end by an upgraded header.

- Support both sides with the temporary walls.
- Notch (or completely cut) space for beam
- Use hangers to secure the floor joists to the hangers
- Remove the temporary walls

My final question - what's the quickest, safest way to build these
temporary walls? Don't laugh, but can I rent them? (I'm thinking of
some adjustable, metal posts and support beams).

Thanks again - kudos to "No" for the "right" answer.

PS: Code office said I could get away with sistering 2x12s but..I'd
rather have the flush beam.

Chu wrote:
Thought I would give everyone an update. The engineer responded that
the span was just too great and that 2x10 unengineered lumber would
have to be spaced 3" o.c. to meet the load requirements. (Although I
don't know what kind of load that would place on the supporting,
exterior walls!

Anyways, it looks like I'm going with a flush beam. It will be
supported at the garage door end by an upgraded header.

- Support both sides with the temporary walls.
- Notch (or completely cut) space for beam
- Use hangers to secure the floor joists to the hangers
- Remove the temporary walls

My final question - what's the quickest, safest way to build these
temporary walls? Don't laugh, but can I rent them? (I'm thinking of
some adjustable, metal posts and support beams).

Thanks again - kudos to "No" for the "right" answer.

PS: Code office said I could get away with sistering 2x12s but..I'd
rather have the flush beam.

What size beam did the engineer recommend? Seems that beam will also
have to span at least 20 ft. Looks like a rock and a hard spot, lose
headroom below or have an intrusion into the floor above. My solution,
while not all that esthetic, was a beam below (2x8 with 1/2" ply
stiffener well glued nailed) supported by 3 posts (each end, one in
middle). Of course there I wasn't trying to make living space, only to
support the sagging ceiling.

Harry K