Mounting heavier items on sheetrock

Remember in the cartoons when someone crashed into a wall and a big chunk of plaster would fall out, revealing horizontal stripes of wood? (Trivia alert: Those horizontal boards under the plaster are called 'lath'.)

Okay, but then later in the same cartoon, a character would be so scared that he'd smash right through the wall leaving the exact outline of his silhouette behind. But here's the thing; they never showed the lath around the edges of the silhouette hole. This drove me crazy, and I'm still not over it.

Your house may have sheetrock (drywall) or lath-and-plaster walls depending on its age. A house that's under forty usually has sheetrock walls.

Now, let's say you need to hang a picture or mount a cabinet. Your hanging options will be determined by the composition of your walls. But which do you have? Try inserting a thumbtack into the wall. If it sinks in easily, you've got drywall. If the thumbtack absolutely won't puncture the surface, your walls are plaster.

Mounting Enthusiasm

Hanging lightweight items on drywall is dead easy. Use a picture hook, and hammer the nail through the angled channel so the density of the drywall supports it.

To hang something that's a bit heavier (up to ten pounds), install anchors. If you've never installed an anchor before, or you've tried but the anchor eventually got wiggly and fell out, here's a quick primer:

Most anchors are plastic and shaped like little projectiles with segmented nosecones that spring apart behind the wall once you drive a screw into them. Here's how to install one:

1. Drill a pilot hole to match the diameter of the anchor. To get a perfect-sized pilot hole, remove a drill bit from your drill index and drop the anchor into the index hole. If the hole doesn't fit, take out a different drill bit and test the anchor again until you find a hole that takes three-quarters of the length of the anchor, leaving the remaining quarter sticking up. Use the winning drill bit to bore your pilot hole.
2. Tap the anchor into place with a hammer.
3. Pre-drill a hole through the object you're hanging, then drive a screw through the object and directly into the wall anchor.

Hanging a really hefty item (more than 10 pounds) like a cabinet, shelf unit or coat rack, takes more diligence. You have to find at least one stud to screw into. (They never showed the studs in the cartoons either. Talk about exasperating.)

Stud Study

Studs are generally 2" x 4" boards spaced 16 inches apart. So theoretically, if you can find one stud, you can find another every 16 inches along the wall.

But wait. In days of yore not all builders were fans of 16-inch spacing. Maybe they were stingy, or lazy, or both. Maybe they were drunk, or measuring the intervals using body parts. But for some reason they sometimes put studs up to 24 inches apart. So if you find old studs in odd positions just shrug and mutter, "Those crazy drunk stud cowboys."

To locate a stud you can use one of the following methods, all of which have failed at one time or another:

1. Drill a small hole, poke a wire through it and fish around to the right and left, hoping to hit a stud. When you do hit one, attempt to place your drill bit over the correct area and drill into the stud. This takes an average of six holes.
2. Draw a horizontal line at the height you want to hang your object. Then drill a series of little holes along the line, about an inch apart, until you hit wood.
3. Walk along the wall, knocking and listening attentively for changes in pitch. Even the pros can screw this up.
4. Find an electric receptacle or switch, which is almost always attached to a stud on one side or the other. Measure from there to your hanging location using 16-inch increments, from the centre of the first board to the centre of the next. (Try taking the receptacle cover or switch-plate off and looking inside the box to see which side is attached to a stud.)
5. Use a $2 magnetic stud-finder, which becomes magnetically aroused when it passes over the heads of metal nails or screws. Trawl back and forth across the wall until you identify a vertical path of nails where drywall is secured to a stud.
6. Use an electronic stud-finder that measures wall density and beeps enthusiastically when it passes over studs (or water pipes, which are always surprising to drill into).

Once you've located a stud, mark an 'X' in pencil over the location. Drill a subtle test hole using a 1/16" drill bit to make sure you hit wood (there will be telltale sawdust in the threads of the drill bit). Then pre-drill for your screw (optional), position your object, and drive the screw through it right into the stud.

You must hit a minimum of one stud to take the main burden of weight. If your object is small and won't reach a second stud, use two screws stacked vertically on the same stud, or use a wall-anchor for the second screw.

Screwy trivia

Guess how much weight it would take to snap a #8 woodscrew?

   a) 150 pounds
   b) 500 pounds
   c) over 1000 pounds

It's c! This is called 'shear strength'; screws won't shear off until there's a huge amount of weight on them. It helps to have conversation starters like this if you're ever in line beside an attractive stranger.