Domakihub How to Use Wall Anchors in Plasterboard the Right Way
Choose the right anchor, fit it correctly, and hang anything securely from hollow walls.
Reviewed by Domakihub home & decor pros · 2026-06-23 · 5 min read
Plasterboard — also called drywall or gypsum board — lines the interior walls of countless Greek apartments, holiday rentals, and hotel rooms, yet it offers almost no grip for a standard screw driven straight in. The video above walks through the installation process clearly; this guide adds the context you need to pick the right anchor type and avoid the mistakes that pull fixtures clean off the wall. Whether you are mounting a towel rail in a rental bathroom or hanging a large mirror in a hotel suite, the right anchor makes the difference between a solid fix and an expensive repair.
Why Plasterboard Cannot Hold a Bare Screw
Standard plasterboard is typically 12.5 mm thick and is made of a gypsum core sandwiched between paper layers. Drive a screw into it without an anchor and the thread bites into soft gypsum that crumbles under any sideways or downward load. The screw loosens quickly, especially in rental properties where items are used frequently.
The solution is a wall anchor — a sleeve or toggle that expands or spreads behind the board, distributing the load across a wider area and locking the fixing in place even when there is nothing solid behind the plasterboard.
Choosing the Right Anchor Type
Plastic expansion anchors (the classic white plugs) suit lightweight items up to around 10 kg such as picture frames and light hooks. Hollow-wall metal anchors, also called Molly bolts, expand into a collar against the back face of the board and handle medium loads up to roughly 25 kg — good for shelves and curtain rails. Toggle bolts use a spring-loaded wing that opens inside the cavity and are the strongest option, rated for heavy loads such as TV wall brackets or large mirrors up to 50 kg or more, though they require a larger pilot hole.
For plasterboard fixed directly onto masonry — common in older Greek buildings — you can sometimes hit the masonry behind if you drill deep enough, in which case a standard masonry anchor is the correct choice. Tap the wall first: a hollow sound means pure plasterboard cavity; a solid thud means masonry is close behind.
How to Install a Wall Anchor in Plasterboard
- 1
Mark and check the location
Use a stud finder or a simple knock test to confirm there is no timber or metal stud at your chosen spot. Stud cavities are typically spaced 400–600 mm apart. Mark the exact drill point with a pencil and check that no electrical cables or pipes run behind the wall — in Greece, cables often run vertically from socket to socket, so avoid drilling directly above or below existing outlets.
- 2
Drill the pilot hole to the correct diameter
Each anchor type specifies a required hole diameter printed on its packaging — follow it exactly. For a standard plastic plug this is usually 6 or 8 mm; for a Molly bolt it is typically 10–12 mm. Use a sharp drill bit suited to plasterboard (a standard HSS bit works well) and drill at low speed to avoid tearing the paper face. Keep the drill perpendicular to the wall surface.
- 3
Insert the anchor flush with the wall surface
Push the plastic expansion anchor fully into the hole until its collar sits flush — never protruding — with the wall surface. For Molly bolt anchors, slide the sleeve into the hole, then tighten the screw with a screwdriver until you feel resistance as the collar bites into the back of the board. For toggle bolts, fold the wings flat, push them through the hole, and allow them to spring open inside the cavity before tightening.
- 4
Drive the screw into the anchor
For plastic plugs and Molly bolts, drive your screw into the set anchor until it is snug — do not overtighten, as this can crack the plasterboard or compress the gypsum. For toggle bolts, tighten until the fitting is firm against the wall face. Use a hand screwdriver for the final turn rather than a power drill set to high torque, which makes it very easy to strip or over-drive the anchor.
- 5
Test the fixing before loading it
Before hanging your shelf, mirror, or fitting, tug the screw firmly by hand to confirm the anchor has locked in place and shows no movement. For heavier items, do a brief load test by applying gradual downward pressure. If the anchor spins or pulls toward you, remove it, fill the hole with a ready-mixed filler, let it cure for 24 hours, then re-drill and start again with the correct anchor size.
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FAQ
- How much weight can a wall anchor hold in plasterboard?
- It depends on the anchor type. Plastic expansion plugs typically hold 5–10 kg for light items. Metal hollow-wall anchors (Molly bolts) can handle 20–30 kg for shelves and curtain poles. Spring toggle bolts are the strongest option, rated up to 50 kg or more depending on the bolt diameter. Always check the manufacturer's load rating and stay within it — in rental properties and hotels it is wise to apply a safety margin of at least 30 percent.
- Can I use the same anchors in a plasterboard wall that is fixed onto masonry?
- Not necessarily. If the plasterboard is glued directly to masonry (dot-and-dab installation, common in Greek apartment refurbishments), there is no cavity behind it. In that case, drill through the board and into the masonry, then use a masonry anchor rated for the load. Tap the wall first — a solid sound with little resonance suggests masonry is close behind, while a hollow boom indicates a true cavity.
- What should I do if an anchor spins in the hole and will not tighten?
- A spinning anchor usually means the hole is too large for the anchor diameter, or the gypsum around it has crumbled. Remove the screw, fill the hole completely with ready-mixed wall filler or a purpose-made anchor repair kit, and allow it to set for at least 24 hours. Once cured, re-drill with the correct bit size and fit a new anchor. In a rental or hotel context, it is better to choose a slightly larger anchor type (for example moving from a plastic plug to a Molly bolt) to get a more reliable grip.