Help With 2nd Floor Joists - Building & Construction - DIY Chatroom Home Improvement Forum


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 09-11-2008, 09:14 PM   #1
Newbie
 
Join Date: Sep 2008
Posts: 3
Rewards Points: 10
Default

help with 2nd floor joists


My house is a balloon framed, 1 1/2 story built in the 1930's and added onto several times. The 2nd floor joists in one room were saging badly and needed to be replaced. After removing the old plaster I found the original joists were hardwood 2 x 6 spaced 24" OC, 12' span. The problem I have is the way the joists are hung. Because of the original 9' ceiling height in the adjacent room, the joists do not set on the stud wall top plate. The joists are face nailed to the stud sides with a 1 x 4 ledger mortised into the studs that the joists set on. I would like to replace these joists with
2 x 12, 24" OC, but I'm not sure how to attach them to the walls. I haven't found anything in the building codes that address using ledgers.

Also, I plan on sistering studs to the original studs that are 24" OC to meet code for 1st floor walls. Is this acceptable? Both walls are set on foundation with 8" block and do not support the roof - the 2nd floor is the only load. Could I set the joists on the sistered studs? Any help will be appreciated!

Advertisement

g heil is offline   Reply With Quote
Old 09-11-2008, 11:09 PM   #2
Registered User
 
Termite's Avatar
 
Join Date: Apr 2008
Posts: 6,520
Rewards Points: 2,000
Default

help with 2nd floor joists


There are provisions in the code for use of ledgers as bearing points. I never see it done, but I believe 2x2 is the minimum requirement. I think it is cheesy.

I really like your idea of bearing the new joists on top of new studs. I think that is the best option for you. If you're sistering new studs to the old studs, you can fasten the new joists to the side face of the old studs and bear them directly on top of the new studs. The new studs take the weight and the old studs provide lateral stability.

While you have it opened up, I'd suggest installing some flat 2x4 horizontal blocking in the wall at or below the ceiling line at the bottom of the floor joists. These blocks are called firestopping and are a code requirement these days and are especially important in balloon framing. In the event of a fire in the wall, they slow its progression and prevent it from traveling into the floor system. They also segment tall vertical sections of stud space, which is also a benefit in a fire. Most inspectors will require fireblocking in a major renovation such as this, since the walls and floor structure is opened up.

Advertisement

Termite is offline   Reply With Quote
Old 09-12-2008, 04:11 AM   #3
Electrical Contractor
 
kbsparky's Avatar
 
Join Date: Sep 2008
Location: Delmarva
Posts: 3,368
Rewards Points: 2,000
Default

help with 2nd floor joists


You could simply fasten a band board on the front of those studs, and use standard joist hangers on that for support.

Doing it this way, you could install the new joists on 16" centers, making for a better floor system in the long run.
kbsparky is offline   Reply With Quote
Old 09-12-2008, 06:35 AM   #4
Newbie
 
Join Date: Sep 2008
Posts: 3
Rewards Points: 10
Default

help with 2nd floor joists


I have thought about installing 2 x 10 ledger fastened to the face of the studs with 3/8 x 4" lags so I can go 16" OC, but is this safe? What about shear on the lag bolts? Has anyone seen this done? And thanks for the advice on firestopping, I already covered the floor openings inside the wall. What about placement of the stops? Are they needed on exterior walls? Thanks for your help!

Last edited by g heil; 09-12-2008 at 06:46 AM.
g heil is offline   Reply With Quote
Old 09-12-2008, 09:14 AM   #5
Registered User
 
Termite's Avatar
 
Join Date: Apr 2008
Posts: 6,520
Rewards Points: 2,000
Default

help with 2nd floor joists


Quote:
Originally Posted by g heil View Post
I have thought about installing 2 x 10 ledger fastened to the face of the studs with 3/8 x 4" lags so I can go 16" OC, but is this safe? What about shear on the lag bolts? Has anyone seen this done?
Yes, but I don't care for the notion of bolting into the studs with the shear load being applied parallel to the grain. I don't trust it as much as direct bearing. If you go this route you need to involve the local inspector (to see what they'll accept) and/or an engineer. The benefit of doing a 2x10 ledger is that it would take care of the firestop as well.

And thanks for the advice on firestopping, I already covered the floor openings inside the wall. What about placement of the stops? Are they needed on exterior walls? Thanks for your help!
You should place firestops at a place that prevents a fire/heat/smoke in a vertical stud space from entering a horizontal assembly, your joists in this case. The typical location is right at or below the ceiling line.
The way I help people understand the requirement is tell them to imagine a smoke bomb in the bottom of the wall once the wall is sheetrocked or closed up. Where can that smoke go? If it can move vertically up to 10', that is ok. If it can move horizontally up to 10, that is ok. But if it can move from vertical spaces into horizontal (or horizontal into vertical) spaces such as floor systems, attics, dropped ceilings, or furdowns, you gotta block it.

Firestops aren't in most older homes, but trust me, they work. I've seen them make the difference between partial loss of property and total loss of property.

FYI...Section R502.6 if the IRC code allows floor joists to be supported on a 1x4 ribbon strip and then nailed to the sides of the adjacent studs. For your application, it would be appropriate and expected that you'd inlet the ribbon strip into neatly cut notches in the studs.
Termite is offline   Reply With Quote
Old 09-12-2008, 07:41 PM   #6
Newbie
 
Join Date: Sep 2008
Posts: 3
Rewards Points: 10
Default

help with 2nd floor joists


After a week of searching you have given me the best info thus far. Thank you for your help!

Advertisement

g heil is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Top of Page | View New Posts