21

I have some plasterboard screws like this:

enter image description here

However, without a drill I have a job getting them into the wall. Am I safe to use normal screws on hangings that aren't going to be taking a great deal of weight? In this case it is a rack of coat hooks.

  • If you can, drill into a stud. It will prevent a whole bunch of problems with crumbling plaster. – dave Aug 31 '12 at 1:37
  • 5
    Find a stud. Mounting a coat rack with anchors is not a good idea, unless you like rehanging coat racks and patching holes in drywall. – Tester101 Aug 31 '12 at 12:44
  • 3
    As far as drywall is concerned "rack of coat hooks" is a great deal of weight. – iambriansreed Sep 4 '12 at 18:02
34

There are several approaches to hanging loads on drywall/plasterboard.

Light Duty - The most common anchors for used for light loads are expanding tubes that grip the sides of the hole they are in and flare lightly behind the hole

plastic anchor

Others like yours, have a wide thread to grab more surface in the drywall itself. Some of the these threaded anchors have a flaring end, some do not.

threaded anchor

The limitation of all of these types is they depend on a small area of drywall to stay solid to hold them. They are good for light loads and when the main force on them is shear force. In a wall application, that means most of the force is pullin down, along the wall (as if you are trying to cut the screw in half right at the wall).

If you put a heavy load on these anchors, there is significant outward force, that is, pulling away from the wall. In a coat rack some of the load is shear (downward) and some is outward. This puts stress on the sides of the hole in the drywall and it crumbles. This is even worse when the load is dynamic (moving) rather than static (non-moving). A hanging coat is static. A coat being pulled form its hook is dynamic. And almost all of that load is outward.

The threaded anchors distribute the load better, but not enough for any significant load. Sometimes this is compensated for by using many anchors. An improvement, but usually not a good solution.

Plastic (or metal equivalent) anchors are almost never suitable for ceiling mounts, where all the load is away from the ceiling surface.

Medium Duty - Anchors for medium duty pull against a larger area behind the drywall to distribute the load.

Expanding anchors go into the hole as a tube and are then expanded behind the hole using a screw, bolt or tool.

molly

plastic molly

There are also toggle type anchors where the expanging section either rotates or springs out to cover a greater area.

metal toggle

plastic toggle

rotating toggle

The advantages of these anchors is that they spread the load far beyond the hole in the drywal itself. While the hole may be prone to crumbling, these anchors rest on an area of solid drywall, from about 1 to 2 inches around the hole. This gives the anchor much more strength to deal with outward loads of medium duty, as well as shear strength. However heavy outward loads, especially dynamic loads, are pulling on on a few inches of thin plaster and paper. Again, adding many anchors helps spread out the load.

Some of these anchors allow removal and reattachment but some do not (for example, spring toggles fall off in the wall when the bolt is removed).

Heavy Duty - On a plasterboard wall, the heavy duty mounting of choice is directly into framing members.

The most common approach is to find studs, the upright framing members that hold up the wall surface. These are either wood or steel. Screws are driven throught the item to be mounted, through the drywall and into the middle of the stud. An alternative is to screw into cross bracing framing. These are wooden or steel sections running horizontally to brace a wall or serve as a firebreak. These are marginally less strong than upright studs, but for practical purposes can hold all but the heaviest loads.

Studs and cross bracing can be found using a stud finder.

Screws should be long enough to reach at least 1 inch into a wodden stud, longer if the load is especially heavy. In steel studs, finer thread screws should be used (sheet metal screws) and length is less of an issue.

In wooden framing, an alternative to regular screws are hanger bolts that can be threaded into the studs and leave a bolt on the outside of the drywall for hanging the object.

hangerbolt

The advantage of hanger bolts is the ability to easily remove and reattach the load using a nut or wingnut.

When there is no framing member in the exact spot needed, it is sometimes worth the trouble to add one. A section of drywall can be removed from the area, a cross brace inserted exactly where you want the mounting and extending horiziontally to the two supporting studs on either side. A drywall patch can be then put back to cover the cross brace (using the drywall section removed or a new piece).

  • 4
    Great answer. Now we have somewhere to point all the future drywall anchor questions to. – Tester101 Aug 31 '12 at 15:05
  • @Tester101 Thanks. If anyone has points missed, or needing clarification, please feel free. – bib Aug 31 '12 at 15:07
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    Wow, this is excellent. – Jivings Aug 31 '12 at 17:37
  • Here's an additional, but expensive, product, that can save you the trouble of patching drywall: the Moen SecureMount. – ELLIOTTCABLE Mar 17 '15 at 22:03
  • I have never gotten the medium duty hardware (first pic) to work out for me. It's too hard to tell when to stop screwing. The heavy duty solution works nearly every time. – Wayfaring Stranger Dec 29 '15 at 19:10
11

The plug you included in your picture is actually a self-drilling anchor. Take the screw out and you will see that the anchor itself has a Phillips head. Screw it into the location in your wall until it is flush with the drywall. Then screw your hook with the screw into the anchor.

Drywall itself is won't hold a screw - after you get past the paper outer layers, it will just break up into powder. The anchor expands in the wall to grip it which lets you put something like a hook on the wall to hold some loads.

If you don't use an anchor, it will almost without a doubt pull out - especially a coat rack holding heavy jackets that are constantly being lifted and re-hung.

8

It's not the shear stress that you're worried about when mounting a coat hook. The bigger issue is the pullout stress which depending on the design of the hook can increases the pullout force.

The benefit of the threaded screw insert that you posted is that the threads are wide and deep. The wide spacing helps to keep the drywall intact and not crumble while the depth of the threads provide better pullout resistance.

The other issue is that these screws will be receiving dynamic loads which will also increases the effect of the drywall crumbling over time if there is any pullout movement. The short and tight threads of a typical screw will simply breakdown the drywall faster and allow complete pullout.

I would definitely recommend using the posed insert or even a small toggle bolts depending on the size of the coat hook.

Using screws directly into drywall should be kept to light static loads.

1

Since you don't have a drill, perhaps consider these metal hammer-in plasterboard fixings. They're designed for plaster, but I've used them to hang a coat rack on drywall and they worked perfectly. They also have the benefit of less damage to the wall if you eventually pull them out. They come in varied weight ratings, so be sure to buy ones big enough for your project.

enter image description here

The WallClaw Drywall Anchors operate similarly - no drill required - but I cannot speak to their performance.

enter image description here

0

They're for holding things up on sheetrock. Instead of using just a regular screw in the sheetrock that can damage it if pulled out, or if you need the extra strength for say a large heavy mirror, then these come in handy. The plastic anchors screw ito the sheetrock until they are flush with it, then the metal screw is used for whatever application you need it for, it screws into the plastic and provides strength.

-1

When using these self-drilling anchors I've found a few things things really helpful:

  • Spot the hole by pressing an awl, big nail, or old philips screwdriver in exactly the right place, to break the surface.
  • Use a plain simple screw driver to put them in, and push hard. Don't even think about putting them in with a drill-driver
  • Buy a pack of the same brand/shape in metal. They're about twice the price, but can be used repeatedly to get the holes started for the plastic version.

Note that my ony metion of a drill here is to say avoid it.

For something that's on the limit of what these anchors will hold, a little glue, e.g. PVA (wood glue), on the threads helps stabilise the plaster around the hole and stops the anchor creeping out.

  • I put the ezanchor spin in anchors all the time with a electric impact and drill, both plastic and metal with no problems. I don't push hard I want the drill point to cut the sheetrock not break it when the threads start to engage I slow down works great for me. – Ed Beal Dec 5 '18 at 14:48
  • @EdBeal I'm not saying it's not possible, with very low speed, a torque-limiting clutch, or ideally both. I'm saying it's not a good idea for those unfamiliar with the fittings (as the OP apears to be). For me, it's also pointless to get the cordless drill out for a job like that, as the most I'd use in one go is probably 6, more commonly about 2. – Chris H Dec 5 '18 at 14:53
  • You actually want speed to allow the tip to cut the material not break it if the sheet rock cracks it only has the strength of the paper so cutting is better than pushing hard. Getting my drill out takes the same amount of time as getting a screwdriver. – Ed Beal Dec 5 '18 at 15:02
  • @EdBeal push hard to start works very well. I've had to patch up where others have put them in with drills, so I've seen the mess that can be made, while using hand tools is (IME) completely reliable. It's an extra trip to the garage for me to get the drill+wall fixings kit compared to screwdriver+kit. I could maybe optimise that but I guess I have a slight preference for hand tools when they're just as good as the power equivalent – Chris H Dec 5 '18 at 15:09

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