How do I fix something to a hollow core door?

The skins on a hollow door are typically three to four millimetres thick with nothing behind them. An ordinary screw grips only that skin, and the first time the door is used the fixing pulls a hole through it.

What you'll need

• hollow door anchors or small toggles
• drill and bits
• bradawl (optional)

Step by step

1. Find the solid areas.The perimeter rails and stiles are solid timber, usually 25 to 40mm wide. There is also a lock block, a solid section on the latch edge roughly where the handle is.
2. Locate them by tapping and probing.Tap along the face; solid areas sound dead. A small bradawl in a spot that will be hidden confirms it — solid resists, honeycomb gives way after 4mm.
3. Prefer the solid edges wherever possible.A coat hook screwed into the top rail or the stile behind the hinge side is a completely ordinary timber fixing and will carry proper weight.
4. Use a hollow door anchor in the field of the door.These are metal or nylon fixings that grip through the skin and then spread or fold behind it, distributing the load over a much larger area than a screw.
5. Drill the hole to the fixing's stated size, no larger.The whole load path goes through the skin around the hole. An oversized hole in a 4mm skin has almost no strength left.
6. Or use a small spring toggle.Where the cavity is deep enough behind the skin, a spring toggle spreads across a wide area and is the strongest option available in a hollow door.
7. Keep the load modest and think about direction.Hollow door fixings resist a hanging load reasonably and a pulling-out load poorly. A hook that is yanked outwards fails far sooner than one that is loaded downwards.
8. Consider an over-the-door hanger instead.For coats and towels, a hooked rail over the top of the door puts the load into the door's solid top rail and needs no fixing at all.
9. For anything substantial, fit a backing block.Cut an access hole, glue a timber block inside the cavity behind the fixing point, patch the skin and fix into the block. It is fiddly but it turns a hollow door into a solid fixing point.

Tips

• The lock block behind the handle is solid — if a fixing can go there, it will hold like solid timber.
• Over-the-door hooks avoid the whole problem and take no strength from the door at all.
• If a fixing has already pulled through, patch the skin with filler and a scrap of card behind before trying again, or the new fixing sits in a hole.

Common mistakes

• Using an ordinary woodscrew into the door face — It grips only 4mm of thin facing skin. Any real load tears a hole straight through and the damage is difficult to repair invisibly.
• Drilling a generous hole to make the fixing go in easily — In a 4mm skin, hole size is the strength. An oversized hole means the anchor has almost nothing to spread against.

If it doesn't work

Questions people ask