Plasterboard Strength?

[Bob Clarkson]

It would be nice if you did manage to hit a joist, or even a noggin. But if it’s 12mm plasterboard, and it’d screwed to timber, which is the way I always install it when doing re-fits it’ll be more than strong enough. Just use the heavy duty fixings out of B&Q, but they really must be the ones that open out inside the cavity. It’d also be nice if it fitted with four fixings.

[Peter Normington]

Warren the plasterboard itself is not strong enough, although they will probably take the weight initially using butterfly fixings, any slight knock and the plasterboard would fail. Plasterboard is ok to fix panels to, but not projecting signs, you will need to determine what is behind the board, usually wooden studding and
perhaps be able to fix to that.

Peter

[Warren Beard]

Thanks guys

How do I know what’s behind it though? It’s going to be in front of a window so should be out of "harms" way.

I don’t want to fix from the ground or suspend from the ceiling for similar reasons, if somebody knocks it hard enough it would hit the glass.

I can’t think of any other alternatives, they currently have a smaller edge lit acrylic panel hanging in from of the window but you can’t even see it through the glare of the glass so needs to be a good illuminated box.

Besides being knocked, if I used 6 or 8 butterfly screws would it at least be secure enough not to fall on it’s own?

cheers

Waren

[Martin Cole]

Warren, that’s a toughy,

I always test by using the finest drill bit I have a drill a few holes here and there to see if you hit a joist etc….but will leave tiny holes.

could you not buy a 1/2 sheet of plasterboard and test it 😕

[Steve McAdie]

You can get detectors pretty cheap that will tell you if there is studding or wires or pipes. Mine gives a different sound to tell the difference between wood and metal.

Steve

[Martin Pearson]

Warren, if it were me then I would be looking for a stud to fix it to. The plasterboard will take the weight if done correctly but any sort of nudge and there is a good chance it will come down. I know you say there isn’t much chance of that but sods law says that it will happen anyway and then you have an insurance claim on your hands. Any insurance company will say it hadn’t been fitted correctly to start with.

Studs are generally sited 2 foot apart and Martins drill method will work but I don’t think it looks very professional personally. A stud detector would be a better option and something you can add to your toolbox for future jobs.
As with anything watch what you buy as some are much better than others and have a practice with it before you go on site. :lol1:

[Martin Cole]

quote Martin:

Martins drill method will work but I don’t think it looks very professional personally.

Nothing professional about me Martin, if it’s a customer I’m not keen on I use a hammer and chisel to find the joists…….. 😛

Let me explain myself, the way to go is a stud detector which I do have or did until I lent it to a fitter, on the last couple of occasions when I have had to find beams in plasterboard I have drilled a few holes and always behind where the sign is to be fitted and has always worked with no more than 4 holes being drilled.

As Martin says a detector is a good addition to the toolbox…but don’t lend it to anyone.

[Warren Beard]

Thanks Guys

Think maybe I will invest in one.

I think it might have something there as the wall is only about 1 foot wide so if close to the window there must be some sort of joist there (I hope)

Thanks a lot

Warren

[Mo Gillis-Coates]

Stud finder will do the trick…. pretty cheap online, I have one that has a digital read out and can tell you where the edge of the stud is and will also sound an alarm if your near any ac/dc current

[Nick Monir]

Warren,

There SHOULD be timber studs every 600mm so you should catch at least one of them. If you only hit one stud I’d also add a few plasterboard fixings. We use the twister type fixings, which is basically a metal screw type fixing with a hefty thread you screw into the plasterboard and the screw goes through a hole inside the fixing. The Fischer ones we use claim to be "stronger than the plaster board itself".

Defo invest in a stud finder. I’ve got a Bosch one that also doubles (as most do) as a detector for wires / pipes and has prevented a number of accidents! Think it was around £80.

Nick.

Sorry, just read it was a projecting box!!!!!!!! Wouldn’t use plasterboard fixings on this, sorry lol 😳

[Graeme Harrold]

Deffo get your hands on the stud/elec finder (should have one anyway) and locate the studs. Plan your box layout to fit. Remove horizontal strips of plaster and notch the verticals to accept battens, then get a plasterer in to cover. fit your boxes to these…….

[Bob Clarkson]

As I said, hitting the stud work would be nice, but you’d be amazed how strong plasterboard actually is, when fitted correctly. Studding, apart from in some old buildings should be 400mm centres, if it is built to any form of building standard/reg, and is now generally screwed to the stud work as oppose to nails.
Having rented out and developed properties for many years, you get to be pretty clued on what plasterboard will and won’t take.

[Martin Pearson]

Bob, I know you have years of experience and wouldn’t want to question what you say but I wouldn’t be happy fitting these to just a plasterboard wall. If they were flush then maybe but as these are a projecting sign and will stand out from the wall 720mm I wouldn’t want to relly on the plasterboard supporting them especially if there is a chance of them being knocked.

[Bob Clarkson]

Totally accept that Martin, and fully agree, I certainly wouldn’t choose to do it. It just seems almost pointless to take the risk when you’re only likely to be 8" at max from a good secure fixing.
It was just I sensed for Warrens post he’d asked more if it would work as oppose to what he should ideally do. I’m guessing he or indeed anyone would have figured it had to be better to screw into a stud, or even through into the wall if necessary, so I guessed there must be more to it, and he didn’t have that choice.

[Warren Beard]

Thanks guys, just to clear a few things up

the height is 720mm and projection length is 540mm, I know it doesn’t change much but not as bad as you might have thought.

Also as mentioned the wall is only a small piece between the window and some built in shelving/display cabinets so presume there is something there but more than likely around the perimeter of the board and not through the centre where I might need to fix the box.

I’ll be having another look soon and check it with a stud finder when I get one and might suggest to the customer to get a builder in to replace that section with something more solid.

There could be solid wall an inch behind the plasterboard but how will I know that and not sure if a stud finder has that facility on it?

Thanks for the replies though.

cheers

Warren

[Glenn Sharp]

Warren

would it be possible to paint up some ply the same width as the wall and pin the ply hitting the outer frame? (or foamex or summat)

Then just fill in the little holes and touch up with a drop of paint

[Bob Clarkson]

Unless you’ve fitted the stuff yourselves, so you know for sure it’s not, you’d be amazed how many bathroom and indeed kitchen cabinets are installed toggle or hollow anchor. I once took a boiler out that apart from the gas pipes, which were taking a fair bit of the weight, was fixed to the wall with self drills.
I wouldn’t do any of the above myself, but I can assure you it’ll work amazingly well. Try pulling 4x toggle fit through 12mm plasterboard, you’re more likely to pull the plasterboard off the stud work.
It’s a bit like fitting a sign with "Pink-Grip" instead of screws, we all know it’d work, but none of us really want to be doing it.

[Peter Normington]

Bob
kitchen/bathroom cabinets are usually 200mm deep and say 600mm square maximum, so the area fixed to is a bit different, a projecting sign of the dimensions Warren is talking about has a width on the board of say 100mm x 720mm.
Plasterboard is fragile, is not a structural material, and even though you say it can be done, if anything goes wrong, the bottom line is Warren will be responsible.
So does he feel lucky?

Peter

[Bob Clarkson]

Kitchen cupboards tend to be nearer 300mm and doubles are often 900mm high and 100mm wide. It is not unusual for them to have an entire crockery set in them along with a mass of canned food and some stuff stacked on to for good measure. The weight is frightening what some people put in them.

Plasterboard is incredibly strong. The plaster is fragile, but the paper isn’t. As a composite it’s a great combination. If you’re not used to working with it, then I agree, paper and plaster don’t sound like they’d be strong, but try and tear half a dozen fixings out of it simultaneously.

But like I said, as much as I now full well it’ll do it, by how hard it is to rip the whole lot out when doing re-furbs, I’d only do it if there were no other choice.

[Martin Pearson]

Warren, if it’s only a short bit of projecting wall then a piece of ply would do the job or you could use something like a bit of brushed aluminium with the screw heads covered with mirror caps to make a bit of a feature out of it. Just another idea :lol1: