Plywood, Osb & Plasterboard vs Home Cinema

RiDo · 17 Jul 2018

Good Afternoon All,

My first post here, but first of all I'd like to say there's a huge amount of helpful information on here from you guys!

This is my first project in my first house. It's a new-build property and I'm planning on putting a basic cinema system in the lounge. It'll include a 65in TV (21kg), an IKEA BESTA cabinet 180x40x0 (upto 50kg) and a 5.1 speaker system (6kg/ speaker) when I can afford it.

[GALLERY=media, 101634]Lounge XTZ2 by RiDo posted 17 Jul 2018 at 1:41 PM[/GALLERY]

[GALLERY=media, 101635]20180619_135040 by RiDo posted 17 Jul 2018 at 1:41 PM[/GALLERY]

I was able to get one of the contractors on site to cut a hole in the plasterboard, and affix some 12mm (maybe 15mm) plywood with steel angles, and then reapply the plasterboard. What's not shown in the photos is the OSB behind where the TV will hopefully be mounted. The white plastic is a conduit for cables.

BEFORE

[GALLERY=media, 101636]20180620_120335 by RiDo posted 17 Jul 2018 at 1:41 PM[/GALLERY]

AFTER

[GALLERY=media, 101637]20180620_153001 by RiDo posted 17 Jul 2018 at 1:41 PM[/GALLERY]

Owing to the mount I've bought, I can only get the brackets across 1 stud. But behind the rest of the mounting holes, there is OSB.

[GALLERY=media, 101639]Screen Shot 2018-07-17 At 13.45.27 by RiDo posted 17 Jul 2018 at 1:49 PM[/GALLERY]

So I wanted some advice as to how to mount the items. I was thinking about using cabinet hangers for the IKEA BESTA.

[GALLERY=media, 101638]Locksonline_29041915P1-500x500 by RiDo posted 17 Jul 2018 at 1:41 PM[/GALLERY]

But for the speakers and TV, I'm a little lost. I was planning on using snap toggles or spring toggles, but I don't think there will be enough space behind to get them through. Any other advice is really appreciated.

Thank you!

RiDo

endecotp · 17 Jul 2018

Woodscrews into the studs or the OSB. No need for e.g. spring toggles behind the OSB IMO, unless it’s very thin. I mean, that’s why you’ve put the OSB there, isn’t it?

I think the more conventional way to do this would have been to put large sheets of ply/OSB over the front of the studs over the whole wall and then plasterboard over that. No need for metal angles etc.

RiDo · 17 Jul 2018

endecotp said:
Woodscrews into the studs or the OSB. No need for e.g. spring toggles behind the OSB IMO, unless it’s very thin. I mean, that’s why you’ve put the OSB there, isn’t it?

I think the more conventional way to do this would have been to put large sheets of ply/OSB over the front of the studs over the whole wall and then plasterboard over that. No need for metal angles etc.

Thanks for the reply. Indeed the whole point of the OSB/Ply was to screw directly into that. Would I need to drill pilot holes? And what size would you recommend? The depth of the plasterboard and ply is about 25/30mm (I can't remember off off the top of my head), with a gap of around 30mm to the thermal insulation. The studs are actually batons (slightly orange uprights) on top of the studs and I was planning on drilling a pilot hole in these, and screwing all the way through. 90mm was my plan.

And if I were to do this again, I would've just screwed a large piece of plywood on top of the plasterboard and painted it, as you suggested!

SFK · 17 Jul 2018

For the cabinet can you use a "Cabinet Fixing Rail" that will be screwed into the wood studs and the plasterboard to give a stronger fixing;
https://www.google.co.uk/search?q=c...4vqbcAhVGJsAKHS76Cb0Q_AUIESgB&biw=360&bih=512
SFK

RiDo · 18 Jul 2018

SFK said:
For the cabinet can you use a "Cabinet Fixing Rail" that will be screwed into the wood studs and the plasterboard to give a stronger fixing;
https://www.google.co.uk/search?q=c...4vqbcAhVGJsAKHS76Cb0Q_AUIESgB&biw=360&bih=512
SFK

Hi SFK,

The cabinet fixing rail is something I had initially intended on using, but was more tempted by the cabinet hangers as they give a degree of adjustment. However I suppose I could couple them with the cabinet hangers to give an even stronger hold. Thanks!

I'm still seeking some help on the following:

- What screws/ fixings do I use to screw into the plasterboard and ply?
- Would I need to drill pilot holes for the screws? (I was planning on doing so for the screws into the studs)

Thanks

endecotp · 18 Jul 2018

RiDo said:
- What screws/ fixings do I use to screw into the plasterboard and ply?

Ones that will fit through the holes in the brackets, and are long enough to go through the PB and wood and not into thr insulation.

- Would I need to drill pilot holes for the screws? (I was planning on doing so for the screws into the studs)

Probably not; good screws will cut their own holes. But if you have thick non-cutting screws you might need a pilot hole. Experiment on some scrap and see what hppens.

RiDo · 18 Jul 2018

endecotp said:
Ones that will fit through the holes in the brackets, and are long enough to go through the PB and wood and not into thr insulation.

Probably not; good screws will cut their own holes. But if you have thick non-cutting screws you might need a pilot hole. Experiment on some scrap and see what hppens.

Cheers for the response. I mean specifics here; I'm a layman in every sense of the word!

I'm looking at:

TurboGold 4 x 45mm for all the fixings into Plasterboard & Ply/ OSB
TurboGold 5 x 90mm for fixings into studs, potentially drilling a pilot hole.

Is there any reason I shouldn't look at lag bolts, or is that overkill?

Thanks

endecotp · 19 Jul 2018

RiDo said:
TurboGold 4 x 45mm for all the fixings into Plasterboard & Ply/ OSB
TurboGold 5 x 90mm for fixings into studs, potentially drilling a pilot hole.

Seems reasonable to me.

RiDo · 31 Jul 2018

Evening all,

I've started this project and put up one of the 2 bars which will hold the TV. I've drilled pilot holes for the large 100mm screws, and screwed straight in with the 45mm screws. The concern I have is that they all spin when all the way in.

I've tested the 45mm in a bit of OSB & plasterboard around 35mm thick, and whilst it holds, it still spins.

Any advice?

Thanks

Tigercubrider · 31 Jul 2018

I am a bit lost as to what you're doing but a 45 mm screw straight into osb shouldn't spin.
Short and fat is fine

RiDo · 31 Jul 2018

Tigercubrider said:
I am a bit lost as to what you're doing but a 45 mm screw straight into osb shouldn't spin.
Short and fat is fine

Hi Tigercubrider,

I've attached a TV wall mount plate to my wall which comprises of OSB fixed to wooden studs (as per some of the earlier images), and then plasterboard on top; around 30mm total. Along with 45mm wood screws, I've placed washers to spread the load of the screw. I think it's the washers which are allowing the screw to spin. The screws without washers are 100mm which are in the studs.

I have to attach an identical bracket a few inches underneath and I'm thinking of using Rawlplug Hollow anchors instead. What would your suggestion be?

Thanks

endecotp · 1 Aug 2018

RiDo said:
I've drilled pilot holes for the large 100mm screws, and screwed straight in with the 45mm screws. The concern I have is that they all spin when all the way in.

Possibilities include:
- You’ve massively over-tightened them, so they’ve stripped out the holes. (How did you screw them?)
- Pilot holes too big.
- Screws have too much unthreaded shank, so all the actual threads are all sticking out behind.

Nothing to do with the washers.

Experiment on a bit of scrap before you do the other one. It looks like you can fit more of the smaller screws for that bracket, but you might want to move it up or down an inch or so and re-do the stud screws.

RiDo · 1 Aug 2018

endecotp said:
Possibilities include:
- You’ve massively over-tightened them, so they’ve stripped out the holes. (How did you screw them?)
- Pilot holes too big.
- Screws have too much unthreaded shank, so all the actual threads are all sticking out behind.

Nothing to do with the washers.

Experiment on a bit of scrap before you do the other one. It looks like you can fit more of the smaller screws for that bracket, but you might want to move it up or down an inch or so and re-do the stud screws.

I didn't drill pilot holes for the 45mm screws, only the 120mm ones (of which there are 2) and they don't spin at all.

So I've either overtightened them or left unthreaded shank. As the thickness of the substrate is 30mm, there will be 15mm of screw sticking out the back.

My plan for the 2nd half of the bracket is to use 2 Rawlplug hollow wall anchors alongside the rest of the fixings, and this time just screw the 45mm wood screws in. Would you say that should be ok?

Tigercubrider · 1 Aug 2018

If hanging a 40" tv on ply, which I do a lot, about four screws and washers put in with a cordless drill works fine for me. I think I could easily hang myself off a bracket that way

Use twin threaded screws and decent washers and it shouldn't get loose.
I think osb might be slightly more likely to strip out but with care it should be fine

TVs are getting a lot lighter every year. I hung a plasma (50) last week that was maybe 5 years old and it was a two person lift whereas the next one was an LCD that weighed almost nothing

Tigercubrider · 1 Aug 2018

Are you sure that bracket is the right way round?