Sistering A Joist With Plywood - 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 11-01-2010, 10:48 PM   #1
Member
 
Join Date: Oct 2010
Posts: 33
Rewards Points: 25
Default

sistering a joist with plywood


is there any benefit to sistering a joist with plywood?

Advertisement

artmark is offline   Reply With Quote
Old 11-01-2010, 10:56 PM   #2
Member
 
Join Date: Oct 2010
Posts: 206
Rewards Points: 150
Default

sistering a joist with plywood


I think if you put 1/2 inch plywood glued and tacked between 2 joists it makes it stronger because its laminated like a header but I don't think just plywood by itself would be very strong. If it's a space issue look into a flitch plate its a piece of steel added to the length of the joist to make it stronger.

Advertisement

guest is offline   Reply With Quote
Old 11-02-2010, 02:28 AM   #3
Member
 
Join Date: Dec 2008
Location: Fairbanks, AK
Posts: 1,847
Rewards Points: 1,000
Default

sistering a joist with plywood


This came up a while ago, and I mentioned using plywood, "glued, screwed, and tattoed" to a single joist. A reply was "I would never spec plywood; worst wood to use, as every other lam is perpendicular to the load". Since then, I did some looking. Here is one link on the subject, and what I interpret it to say is "If that is all the room you have, then it will help, but a solid piece of wood would be better" because of the lam situation. On the other note, I'd be real careful about putting steel into a header; a floor joist, sure. Steel is way stronger than wood, inch by inch. Art: Did we talk a bit ago on a different thread about the steel straps?

http://www.finehomebuilding.com/how-...-up-beams.aspx
jklingel is offline   Reply With Quote
Old 11-02-2010, 10:07 AM   #4
Member
 
Join Date: Oct 2010
Posts: 33
Rewards Points: 25
Default

sistering a joist with plywood


yes I have a dilema I have a built up beam side loaded bolted together there is a wire hole drilled in the no drilling holes range of 2" trying to find a fix other than taking the house apart or praying it never fails
artmark is offline   Reply With Quote
Old 11-02-2010, 01:50 PM   #5
Member
 
Join Date: Dec 2008
Location: Fairbanks, AK
Posts: 1,847
Rewards Points: 1,000
Default

sistering a joist with plywood


a hole for a wire is typically pretty small. if it is near the top, it is likely not a big deal. if there is concern, employ a couple of the methods suggested and go to sleep. too, if there is room, hang a 2x4 or 6 underneath the problem joist, and tie them together with plates of plywood, 1x8s, or sheet metal.
jklingel is offline   Reply With Quote
Old 11-05-2010, 10:23 AM   #6
Member
 
Join Date: Oct 2010
Posts: 33
Rewards Points: 25
Default

sistering a joist with plywood


Thank you, hole is on tension side been there for 12 years I do want to sleep! because of the bolts and the distance from next joist sistering will not work, also no head room what about metal straps does any one have a link?
artmark is offline   Reply With Quote
Old 11-05-2010, 01:42 PM   #7
Member
 
Join Date: Dec 2008
Location: Fairbanks, AK
Posts: 1,847
Rewards Points: 1,000
Default

sistering a joist with plywood


Article on this subject is in Fine Home Building, Dec 2006/Jan 2007, "Ways to stiffen a bouncy floor", BY MIKE GUERTIN AND DAVID GRANDPRÉ, pgs 90-95. After 12 yrs you are still worried about it? Install the straps; sleep well. j
jklingel is offline   Reply With Quote
Old 11-05-2010, 09:26 PM   #8
Member
 
Join Date: Oct 2010
Posts: 33
Rewards Points: 25
Default

sistering a joist with plywood


J thank you but does not things like this get worse over time?
artmark is offline   Reply With Quote
Old 11-05-2010, 10:19 PM   #9
Civil Engineer
 
Join Date: Mar 2009
Location: Boston
Posts: 4,297
Rewards Points: 2,172
Default

sistering a joist with plywood


Go back to sleep. Relax. If the joist has held up 12 years, you are OK unless you change the load on the joist. Unless you go beyond the elastic limit on wood, a constant load does not do long term damage to wood.
Daniel Holzman is offline   Reply With Quote
Old 11-05-2010, 10:22 PM   #10
Member
 
Join Date: Oct 2010
Posts: 33
Rewards Points: 25
Default

sistering a joist with plywood


Thanks Guys maybe some brandy tonight if you were near by I would invite you over

Advertisement

artmark 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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Dryer duct hole thru band joist & floor joist justplumducky General DIY Discussions 12 10-05-2010 01:31 PM
question about joist sistering Tonglebeak Building & Construction 9 09-11-2010 12:04 PM
Supporting joist under cracked tile JT31 Building & Construction 2 08-26-2010 09:00 AM
Jacking and Sistering Floor Joist Captain.Sassy Building & Construction 17 08-11-2010 02:30 PM
How to repair floor joist when sistering is not an option jmagee3d General DIY Discussions 2 06-05-2009 03:33 PM




Top of Page | View New Posts