I am trying to secure a sconce that is falling away from the wall. The electrical box in the wall is not braced against anything, and the weight of the sconce pulls it partway through the opening in the plaster.
How do you secure an electrical box that when there is no adjacent stud?
Janet
Listeners write in about fireplaces and ask questions about sharpening hand tools, easier wiring upgrades, and fixing cedar siding.
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.
Start Free Trial NowGet instant access to the latest developments in green building, research, and reports from the field.
Start Free Trial Now
Replies
I'd change out the box to an old work type.
You can also add box anchors. They are sheet metal and you bend the ears over into the box.
What is an "old work type" of box?Janet
Old work boxes are boxes made to be installed after the walls are put up. New work boxes are placed before the wallboard, plaster etc is installed.Old work boxes have various types of anchors built in. I like the plastic ones which have a screw you tighten, which flips up a flag that holds against the back of the wall. Some have screws that expand a flap on the side of the box. Some have a spring metal clamp that flips out when the box is pushed into the wall, then a screw is tightened to wedge the spring against the back of the wall. Sometimes one type is preferable, sometimes another one is. Blocking to a solid stud is preferable, but old work boxes are easy to install.
I'd use "tiger grip" boxes for switches, but not for outlets or anything that will get stress put on it.
I hope she's talking about a light weight fixture. That's why I said solid blocking would be better.
I was agreeing with what you said about old work boxes being good for certain things.
Edited 10/25/2009 5:19 pm by Jencar
The best way would have been a couple of blocks between adjacent studs, but you still have have options. See attached document. There is a box with drywall ears on the third page.
Check with your local electrical supply.
If it's a fairly heavy fixture, or prone to being knocked, I would cut out some drywall and install blocks. Drywall repair isn't that difficult.
Scott.
Thank you--Those box anchors are a clever idea. Should have realized that there is a gadget for every problem I am likely to encounter.Janet
These type mounts are available most places that sell electrical supplies.
http://www.erico.com/products/CADDYcfcOldWrkBxMnt.asp
Janet,
Get a can of Great Stuff minimally expanding foam for doors and windows (light blue can). Remove the sconce. Run blue masking tape on the wall around the opening, just shy of the hole in the plaster.
Position your electrical box in the opening so that it is correctly situated. Use a couple of cardboard shims, etc. between it and the plaster opening edges to hold it tight. Then shoot the Great Stuff around the perimeter of the electrical box. If some gets behind the box, all the better. Let it dry, cut off the excess, and remove the tape and cardboard shims.
That box ain't goin' nowhere. Trust me, it works.
DIA
Actually, foam that expands more also hardens more. The expansion can also seat it firmly against the opposite wallboard
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
You could use an "old work" box as several have mentioned. There are a half-dozen different designs available -- I kind of favor the plastic ones with the little wings that swing out when you tighten the screws.
Another option, if the sconce is heavy, and if it's attached to a round/octagon box, is to remove the box (carefully slip it off the wire) and install a fan bracket in the wall. There are fan brackets made for "old work" that go in and brace between opposing joists (or, in this case, studs), tightening with a turnbuckle mechanism. (The depth of the wall might be a problem in your case, though.) Once a fan bracket is installed a fan box can be installed to receive the sconce.
There are specialized hardware that can accommodate this scenario - have you heard of Rework boxes? This can be installed after the first phase of construction.
- https://www.electricianswindsor.ca