How to install a shelf on a plasterboard wall?

[Tshelf]

Hi,

I want to build a shelf in the gap between a built-in closet and the door of a room. The shelf itself is a piece of 17mm plywood. One of the sides will be attached to the door frame. I was planning on attaching 42x19 pine onto the studs of the 3 walls, but the closet side has no studs. Will these drywall anchors do the job? I'm considering making a wooden frame with supports running down the middle, but I'm not sure if its necessary.

[MitchellMc]

It really comes down to how much weight you’re planning to put on the shelf @Tshelf. Start by working out roughly how heavy the shelf itself will be, then estimate the total load once you’ve placed items on it. The Nylon Wallmates you’re referring to are rated up to about 24kg each, but I’d never recommend loading them to their maximum. Working off around 15kg each is a much safer and more realistic guide, as that gives you a buffer for variations in plasterboard condition or installation quality.

That said, it’s generally best not to rely on plasterboard alone for shelving, especially if you plan to store anything heavier than lightweight items like towels, blankets, or décor pieces. If possible, fix into at least one or two studs or the door frame for strength, then use wall anchors only to stabilise the remaining side.

If the side against the closet has no studs, your idea of making a wooden frame or cleat system is a good one. You could fix 42 x 19 battens along the wall where there are studs and then run a support piece down the middle or across the back to distribute the load more evenly. This way, the shelf won’t depend solely on the plasterboard for strength, and it’ll feel much sturdier and safer.

Please let me know if you have any questions.

Mitchell

[Tshelf]

Hey Mitchell,

The plywood weighs around 6kg and the shelf will be holding 15kg at most. 

I'm planning on attaching the frame to be studs on the back wall and door frame, with the drywall anchors on the closet wall.

Should I go with 1 or 2 middle supports, or will it not make much of a difference in this case? I'll be using 75mm timber screws, should I use two screws or just one to attach the supports to the frame? 

Thanks again

 Studs marked by crosses

[EricL]

Hello @Tshelf 

I'm confident that the corners of the closet wall will have timber supports and that somewhere in the middle of that closet wall is a timber support. The recommendation that Mitchell has suggested is quite sound and will offer support to that section of your shelf. In regards to the drywall anchor, I suggest using Tox M6 Flip Toggle Bolt as an alternative. I propose installing a minimum of four toggles to evenly spread the load.

As to the supports, I suggest putting two supports and two screws for each end of the support. My best advice is to drill pilot holes to prevent splitting the timber. 

If you need further assistance, please let us know.

Eric

[AlanM52]

Hi @Tshelf,

I suggest rails and shelving brackets fixed to studs and white carcass shelving.

  

Cheers

[Tshelf]

Hey @EricL,

There's a metal angle in the corner but I can't locate any other studs. I've drilled some holes near the the metal and middle of the wall previously but there's only empty space or more drywall. Is screwing the wooden frame to the metal an option?

Hi@AlanM52,

There's going to be other things on the wall so I don't think the rails will work in this case. I appreciate the suggestion.

[EricL]

Hello @Tshelf 

I'm afraid screwing into the metal angle is not an option. If you've no access to the timber support then I suggest still going with the Tox M6 Flip Toggle Bolt. 

Please keep us updated with your progress, we look forward to seeing your shelf installed.

Eric

[R4addZ]

Ok so it would be most unusual for there to not be a wooden support behind the metal corner because the plasterboard has to be supported in the corner and the metal is simply there as a support for the corner of the plaster. There is also probably a timber support in the corner as the plasterboard needs support there too but probably on the other wall. Studs (as the uprights are called) are usually no more than 600mm apart so search for another support based on those measurements remembering that the 600mm is based on centre to centre so if you clip the outside of one and have a slight imperfection in distances then you will need to cast around for the fixing or get a stud finder to be sure!

[Tshelf]

Hi @EricL,

When drilling holes for the toggle bolts I hit this waxy orange stuff. Any idea what it could be, maybe insulation? 

Hi @R4addZ, didn't see your message until after I drilled some holes in the wall. I think I did find a stud about 100mm from the corner. I poked a paperclip through the other hole and felt something hard. Drilled a smaller hole next to it and I think I hit the stud. 

[EricL]

Hello @Tshelf 

The waxy orange substance you’re describing could be a few different things depending on the wall type and location. If you’re drilling into plasterboard or gyprock, the most likely explanation is that you’ve hit a section of old adhesive or bonding compound used during installation. Some wallboards are attached using construction adhesive, which can appear waxy and range in colour from amber to orange as it ages.

If your wall is older, another possibility is that you’ve reached a patch of expanding foam or insulation resin that was injected for sealing or soundproofing. These materials often have a soft, waxy feel and can show orange or tan hues once cured. They’re generally harmless and safe to drill through, though they can clog drill bits a little.

As a precaution, if you notice any oily residue or strong chemical smell, stop drilling until you’re sure it’s not an old cable sealant or electrical insulation (rare, but possible in walls with retrofitted wiring). Use a stud finder that can detect electrical wiring just to be sure. However, if it’s dry, slightly waxy, and has no odour, it’s almost certainly old adhesive or insulation resin.

If you need further assistance, please let us know.

Eric