How to install timber corbels in a doorway?

Clarke14

Hi, I'm looking to install timber corbels about 700g weight in the upper corners of an open squared archway. They would be attaching to plasterboard painted with primer, and then I'll be painting topcoat over them. I've come across a lot of different suggestions for the best way to attach them - the most common one seems to be to use construction adhesive and then a nail or screw through the lower end of the corbel, but I'm concerned that this might not hold firm enough on plasterboard. I've included a picture of the corbel in question and the squared archway where it's going to go. What's the best way to secure them?

MitchellMc

Hi @Clarke14 ,

At around 700g each, those corbels aren't especially heavy, but I'd still want them mechanically fixed rather than relying solely on adhesive.

If possible, I'd first check whether there's timber framing behind the plasterboard at the edges of the opening. Doorway and archway openings are typically framed with timber studs, so there's a good chance you'll have something solid to fix into. If you can hit timber, I'd use a quality construction adhesive like https://www.bunnings.com.au/selleys-130g-liquid-nails-fast-grab-strong-adhesive_p0615431 on the mating faces and then drive a couple of https://www.bunnings.com.au/zenith-8g-x-75mm-countersunk-rib-head-chipboard-screws-50-pack_p2408472 through the corbel into the framing from underneath. You can then fill the screw holes with https://www.bunnings.com.au/timbermate-250g-pine-wood-filler_p1560693 before painting for a neat finish.

If there isn't any timber behind the plasterboard where the corbels are positioned, then heavy-duty plasterboard anchors in combination with construction adhesive would be the next best option. Given they're decorative rather than load-bearing, that should provide plenty of holding power.

Below, I've marked where I suggest you pre-drill and screw through the corbels.

Please let me know if you have any questions.

Mitchell