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

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

Reply
 
Thread Tools Search this Thread Display Modes
Old 03-03-2012, 11:13 AM   #1
Member
 
Join Date: Oct 2011
Location: SF Bay Area, CA
Posts: 150
Share |
Default

Do I need to beef up my garage ceiling joists?


My house was built in 1957. The garage (24'-long, 20' wide) only has 3 ceiling joists, 6' apart. I am planning to put a storage space up there between the two joists using a piece of 3/4" plywood (see photos). I expect no more than 200 lbs of stuffs will be up there - mostly my son's used toys.

Do I need to put two more ceiling joists beneath the plywood?

If I do need, then how? Do I need to take off the beam that supports the garage door opener rail? Can I use two 12' long 2x6 pieces and join them together for this purpose?
Attached Thumbnails
Do I need to beef up my garage ceiling joists?-cimg9019_s.jpg   Do I need to beef up my garage ceiling joists?-cimg9018_s.jpg  


Last edited by htabbas; 03-03-2012 at 11:18 AM.
htabbas is offline   Reply With Quote
Old 03-03-2012, 12:58 PM   #2
Member
 
Join Date: Dec 2008
Location: Fairbanks, AK
Posts: 1,847
Default

Do I need to beef up my garage ceiling joists?


tough call for someone from afar. i'd either have an engineer look at it, or, if you like to gamble, put a tight wire below the truss, measure its present deflection, and then watch it every few weeks to see if it is bowing. you are, of course, assuming it will bend before failure, and that may be a precarious assumption. a good carpenter should be able to add a similar truss in there w/out gross expense. have a local cat look at it, though.

jklingel is offline   Reply With Quote
Old 03-03-2012, 01:17 PM   #3
Structural Engineer
 
Join Date: Feb 2012
Location: Chicago, Illinois
Posts: 46
Default

Do I need to beef up my garage ceiling joists?


If the roof trusses are spaced at 6 feet on center, and properly designed to support a 6 foot wide width of the roof, then additional ties are not needed as far as roof rafter thrust is concerned. In that case, you would add the ceiling joists solely to support your storage loads.

If the roof ridge is sagging, as is the case with many older garages, you probably need to add ceiling joists across every rafter pair. (as is specified in the International Residential Code)

The roof pitch looks shallow, which results in a larger amount of horizontal force from rafter thrust.

Most of the old garages I see have sagging roofs and walls bowing outward as a result of a lack of ceiling joists to resist horizontal rafter thrust.
House Engineer is offline   Reply With Quote
Old 03-03-2012, 11:05 PM   #4
Registered User
 
Join Date: Mar 2009
Posts: 9,968
Default

Do I need to beef up my garage ceiling joists?


Those look like rafters with a ridge board to me. Someone added diagonal struts to help carry the over-spanned rafter tie you have the plywood on. They also added purlins (more weight) without the struts, so it appears. Holding a straight-edge piece of paper up in front of my screen, it appears the closest tie is sagging 2-3" in its length and the second one = 4-5". I've installed those garage doors before and there is a fair amount of weight loading that center tie when the door is open. Remove the plywood..... please.

Gary
__________________
If any ads are present in my answer above, I do not condone/support/use the product or services listed, they are there against my permission.
Gary in WA is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Create Garage Ceiling For Insulating traeki Building & Construction 4 10-01-2011 10:11 AM
Garage ManCave Please Help!!! ManCaveMark Building & Construction 7 09-14-2011 03:01 PM
Replacing garage 2x4 ceiling joists PAY22 Building & Construction 2 10-30-2010 03:50 PM
Garage ceiling and attic storage DIY KEN Building & Construction 7 01-06-2009 04:57 PM
Drywall Garage Ceiling Recommendations jsjames Building & Construction 6 08-22-2007 03:47 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.