Originally Posted By: staylor This post was automatically imported from our archived forum.
Kevin,
I am attempting to attach a rough sketch of a wall and a wall that is racked. A picture is worth a 1000 words. If you are unable to view the sketch, imagine a rectangle as being a properly braced wall and a parallelogram as being a wall that has racked. To prevent racking, you can install diagonal let in bracing at the corners which was most commonly used in balloon frame construction. In modern platform framing, the exterior sheathing, if properly installed at the corners, will be sufficient to prevent racking.
Originally Posted By: staylor This post was automatically imported from our archived forum.
I tried that , don’t know if it worked. I am not as computer savvy as I would like to be. I thought I was pretty good when I found some program on my computer that would allow me draw images and then I really impressed myself when I got it to attach to my message. Now, my edited message has 2 boxes with Xs where i wanted the picture to go. I’ll keep trying.
Originally Posted By: dvalley This post was automatically imported from our archived forum.
Steve,
Your pic will not post because you need to convert your file from a .tiff file to a jpeg file. Convert and post again.
Originally Posted By: roconnor This post was automatically imported from our archived forum.
Steve did a pretty good job of describing racking. You can also think of it as the top of the wall moving (in the direction of the wall), while the bottom doesn’t move. The wall covering or diagonal braces prevent that movement …
About the pics, in addition to having no spaces in the file name, the size must be less than 100k ...
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: jpeck This post was automatically imported from our archived forum.
Take a cardboard box, lay it on its side and leave both the bottom and top closed. Push on on top edge, pushing toward the other top edge. The entire box moves sideways. If you glued the box down, it would be strong.
Now, open the top and bottom of the box (so you can see through it). Now push on that top edge, the box leans to the other side, in the direction you are pushing it. The box is racking.
The top and bottom acted as the sheathing and wall covering, adding strength to the wall. Without them, or with weak coverings, the wall can be pushed over, just like the box,until it collapses onto itself.
There are many forces which can rack in inadequately braced wall, one of which is wind.
Originally Posted By: roconnor This post was automatically imported from our archived forum.
… the basic version is FREE and it comes with some basic photo editing features … CLICK HERE
ekartal wrote:
Is floor joist bracing just as important?
Yes. Joists need to be blocked/connected at the ends to keep them from tipping over (rotating), and deeper joists (larger than say 2x12) need blocking/bridging about every 8'-0" to keep them from twisting under load (IRC R502.7 as a guide)
If the floor joist blocking/bracing is not installed, the entire floor structure can "rack" ... or shift sideways relative to the supports/foundations ... 
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: Kevin Blackwell This post was automatically imported from our archived forum.
All,
Thanks for the breakdown and the illustration of wall racking
I think the cardboard box did the trick.
If the truth be told this was racking my brain!!!!!!!!!!!!!!!!!!!!
Is it safe to say that wall racking is prevented by proper bracing & solid or drywall sheathing.
Thx Kevin from Houston,TX preparing for pro.inspec.exam
Originally Posted By: jrooff This post was automatically imported from our archived forum.
Typically RACKING is a term we use in construction. After framing up a wall, most of the time we do this laying on the floor, pick it up and slide it in to it’s place, nailing the bottom plate. After all the walls are built we put a level on them to make sure there plumb, most time there not so we RACK the wall the way they need to go to make them plumb. Put on the top plate to help tie it in place. This way all the plywood or OSB sheathing will land OC (on center) of all the studs. The wood exterior and sheet rock inside do a fine job holding everything in place.
