anything better than a Molly Screw?

[RobertL]

I'm fixing a s'ingle point' shower head support by the bath on a tiled, plasterboard stud wall. I thought I had chosen a place with a stud behind it, but when I drilled through 10mm of tile and then 12mm of plasterboard I hit air :-( I could kick myself!

Is there anything better than a Molly screw in this situation? I mean those anchor bolts with legs that expand out behind the plasterboard.

I'd like something that has very long expanding legs so as to spread the strain tp the biggest area.

any thoughts?

Robert

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember RobertL saying something like:

The traditional sprung toggle type is your best bet, iwt.

as an illustration, and if you're lucky you can find them with various lengths of screw and toggle in your local hardware store.

[Roger Mills]

I hate sprung toggle fixings! If you even need to remove the screw, the toggle falls down inside the cavity, and is lost for ever.

[Dave Liquorice]

I'd go for the Molly Screw as the fixing stays in the wall if you need to ever need to remove it, they also spread the load all round the hole. With toggles if you ever remove the scre the toggle drops down the cavity...

Snag here would be finding a Molly Screw with a 22mm+ plain shank before the bend point.

[Roger Mills]

What's on the other side of the wall? The strongest solution - if you can do it without too much disruption - would be to remove some plasterboard [1] from the other side, fix some timber inside to screw your shower fitting into, and then make good the damage.

[1] A 4" square hole would probably be enough, and could be cut neatly with a multi-tool - and the bit you cut out could probably be stuck back in, using battens and gripfill, without even distrubing the plaster skim and paint or wallpaper.

[RobertL]

I did consider this, but the otehr side has just been decorated. It might be easier to remove a tile wit ha fein saw and then repalce it after addig a noggin.

Someone should make a 'spray on' coating with a backward facing nozzle to coat the back of the P/B with something that dries strong. Then mully screw..

Robert

[Peter Parry]

fastenings often don't work. There isn't enough room for them to start to spread outwards. If it is a stud partition you will be OK, if it dry lining on an external wall you probably won't be.

[Mike Clarke]

should grip anything between 16 and

32mm. Since the wall is tiled you'd need to cut off or flatten the two anti rotation spikes on the flange that normally dig into the plaster. This might make it a bit tricky to get it to expand by screwing (oiling the threads might help) but a setting tool for these things is well worth getting if you need to fix more than a few things to plasterboard. Screwfix sell the Rawlplug setting tool which should work equally well with these fixings, they also have the more expensive Rawlplug version of the fittings but only 52mm long which will only cope with thicknesses up to 16mm. You might be able to find genuine Rawlplug M6 x 65 fittings elsewhere, according to Rawlplug's website these grip thicknesses from 15 to 28mm

[The Medway Handyman]

[jsabine]

These will be fine, and work well through tiles.

Flatten them - just bend 'em with pliers. They're cut from the flange anyway, so flatten neatly back into place.

They also do a setting tool for under a tenner - #12429 - and at that price trying to expand the fixings by screwing is a mug's game. It's slower, risks chewing the head, and is a real pain if the anti-rotation spikes don't bite, especially as you'd be well advised to drill a hole through tiles a bit oversized.

[jsabine]

I'd heard Molly Bolt, but never Molly Screw - London, though I can't remember who I heard it from

[Mike Clarke]

Ah, that's the one I originally had in mind but couldn't find. They only had the Rawlplug and the very expensive Fischer tools in the cavity fixings section so I assumed that was all they stocked now. The unbranded one is marginally cheaper than the Rawlpug and one of the user reviews confirms that it works well with the cheaper Screwfix cavity fixings.

In theory any insertion tool should work fine with any brand of fixing but might not always be the case. Some years ago I picked up an el-cheapo kit of fixings with an insertion tool. The downside was that the screws were only M4 and the tool wouldn't accept the heads of M5's although it could cope with the shanks. Apart from that the tool works fine so I just use a M5 screw with a filed down head which I keep for setting only, it's only a moments job to take the original screw out and replace it after setting..

[RobertL]

There's a 100mm gap, with some rockwool in it.

thank yo uall for your help,it's been very useful indeed, particularly the links to actual parts and tools.

Robert