Hollow wall fixings

To answer my own question, it's just struck me that I could use standard masonry-type plugs glued into reasonably close-fitting holes.

You could run a self tapper into the steel and use that to fix the blinds - then you'd only need the smallest of pilot holes.

More often, these lintels are catnic hollow steel box lintels and are about fairly thin, less than 2mm steel.

If you have a bit of a gap behind the plasterboard (more than about 3mm) these will work really well:

I've been very impressed - had half a medium single panelled radiator hanging off these successfully (the other end was screwed into a stud)

You're going to drill into the base of the lintel for this, so you could tap the hole and use a machine screw?

I guess the lintel is super-strong so a couple of holes won't matter.

Are those better than the self-drill ones?

I thought maybe the OP is worried the plasterboard isn't well enough fixed?

Bert Coules was thinking very hard :

If you have to drill the steel, why not drill and tap a small hole?

Thanks for the various thoughts. Tapping the steel honestly hadn't occurred to me, possibly because the arms (surely not the correct term) of my tap holder are too long for the location of the holes.

Self-tappers are a nifty idea, though to judge from the effort I had to put into drilling the pilot holes, the steel is a fair bit thicker than a couple of mil.

I'd not encountered those Gripit gizmos, so I'll check them out. They look as though they require a reasonably sizeable hole, though not into the metal, happily. I think the plasterboard is firmly enough fixed, and the blinds are the vertical-slat types so there won't be any downwards pull in operation (though the fabric slats are surprisingly weighty - more so than I was expecting).

Since I have now drilled a wallplug size hole though the steel in one location, I might try sticking (in the adhesive sense) a plug, as a test.

Thanks again.

You can grip the tap in the chuck of a drill, and then go dead slow of course.

It would be tricky though to do the regular backing-off, surely? Though not impossible.

Thanks for the thought.

Ilve had considerable success in drilling ragged holes in plasterboard and injecting car body filler thrugh them to form a 'dab' of loaded polyester resin behind the board

That can be treated like wood and takes wood or self tap screws. If backed by metal drill into that as well.

When dealing with plasterboard never be afraid to remove sections, do whatever is necessary behind and put back., A skim of finishing plaster and a sand followed by a lick of paint mekes it all good again.

If there is a steel plate, use self tapping screws.

Not with my plastering it doesn't: that's a skill I've never even come near to being able to tackle acceptably, let alone well. But thanks for the thought.

You missed the bit where I said 'sand'

if like me you can plaster as well as you cant ice a cake, sandpaper makes all great again

A very good and cogent point. Sandpapering, I can do.

Why not drill a small hole and use a self tapping screw?

Or even a good quality filler if you CBA with plastering.

Yes, that seems to be the favourite suggestion, thanks. But there's also been some doubt expressed about driving a self-tapper into a hefty steel lintel.

I have blinds fixed into plasterboard with ordinary plugs and woodscrews. Been up for nearly 20 years so I can't remember how long the screws are.

Rivnuts are useful if you think the lintel is too thick to self tap. Only downside is the cost of the setting tool although there are some cheap ones on eBay which may last long enough to do your blinds.

Richard