mdshunk
January 13th, 2004, 07:57 PM
Installing new device boxes in old work can be a frustrating event. I thought I'd share a few things that have helped me.
PVC OLD WORK BOXES - I don't especially like them. To start with, you have to cut a rather large hole in the wall for them. If the wall is an old plaster job, some crumbling around the edges is inevidable. By the time you have a big hole sawed through the plaster and lath, plus what crumbles away, the cover plate often does not cover the damage. I'm an electrician, not a plasterer. I'd rather avoid fixing walls if I don't have to. Another reason I don't like PVC old work boxes is because you normally don't just saw a rectangular hole. The hole is often a weird shape to accomodate the "wings" used to hold to the old work box in place.
Metal Old Work Boxes - This is one step better in my opinion. You don't have to saw nearly as big of a hole in the wall to get the box in. This increases the likelihood that the cover plate will completely cover any collateral damage of the wall. Still, normally you have to saw a weird shaped hole in the wall to accomodate the built in old work box support devices. This type of box can also be somewhat expensive compared to a regular metal new work box.
Metal New Work Box - This is my preference for old work. Not only is the box cheap enough, but you can saw a regular rectangular hole for it. It's smaller than a PVC box, so the cover plate will cover well. I choose boxes with beveled back corners for old work situations. This allows you to install the romexes into the box, and have space to bend the wires into while you push the assembly into the wall opening. I try to mount the box right next to a stud for a very sturdy fit. Even in old work, mounting to a stud should be attempted if at all possible. I choose a style of box that has two nail holes in the side of the box. I install two 1 1/4" roofing nails through the inside of the box into the stud. Of course, you can't fit your hammer inside the box, so I rest the side of a 1" cold chisel on the head of the roofing nail and strike the shank of the cold chisel with a hammer to drive the nails flat. Makes for a real sturdy install. On occasions where mounting directly to the side of a stud is not possible (or undesireable), I generally use what are called "madison straps". These are thin sheet metal straps, shaped like the letter "F", that are slipped in on each side of the box. The straps rest on the inside of the wall, and they are bent over tightly inside of the box. Also makes for a sturdy install if done with care.
I'm still waiting for someone to invent a box that will mount in a wall that just crumbles to oblivion when you try to saw an opening in it, and the lath splinters right away. ;)
PVC OLD WORK BOXES - I don't especially like them. To start with, you have to cut a rather large hole in the wall for them. If the wall is an old plaster job, some crumbling around the edges is inevidable. By the time you have a big hole sawed through the plaster and lath, plus what crumbles away, the cover plate often does not cover the damage. I'm an electrician, not a plasterer. I'd rather avoid fixing walls if I don't have to. Another reason I don't like PVC old work boxes is because you normally don't just saw a rectangular hole. The hole is often a weird shape to accomodate the "wings" used to hold to the old work box in place.
Metal Old Work Boxes - This is one step better in my opinion. You don't have to saw nearly as big of a hole in the wall to get the box in. This increases the likelihood that the cover plate will completely cover any collateral damage of the wall. Still, normally you have to saw a weird shaped hole in the wall to accomodate the built in old work box support devices. This type of box can also be somewhat expensive compared to a regular metal new work box.
Metal New Work Box - This is my preference for old work. Not only is the box cheap enough, but you can saw a regular rectangular hole for it. It's smaller than a PVC box, so the cover plate will cover well. I choose boxes with beveled back corners for old work situations. This allows you to install the romexes into the box, and have space to bend the wires into while you push the assembly into the wall opening. I try to mount the box right next to a stud for a very sturdy fit. Even in old work, mounting to a stud should be attempted if at all possible. I choose a style of box that has two nail holes in the side of the box. I install two 1 1/4" roofing nails through the inside of the box into the stud. Of course, you can't fit your hammer inside the box, so I rest the side of a 1" cold chisel on the head of the roofing nail and strike the shank of the cold chisel with a hammer to drive the nails flat. Makes for a real sturdy install. On occasions where mounting directly to the side of a stud is not possible (or undesireable), I generally use what are called "madison straps". These are thin sheet metal straps, shaped like the letter "F", that are slipped in on each side of the box. The straps rest on the inside of the wall, and they are bent over tightly inside of the box. Also makes for a sturdy install if done with care.
I'm still waiting for someone to invent a box that will mount in a wall that just crumbles to oblivion when you try to saw an opening in it, and the lath splinters right away. ;)
