Turning plasterboard wall into ply lined wall (in internal garage)

Forums › Home Workshop DIY › Turning plasterboard wall into ply lined wall (in internal garage) - easy?

phrozenpenguin

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#318598 2-Feb-2025 22:35

Looking at an internal access garage with "normal" plasterboard finish/white paint, in a ~15 year old property. Considering lining one wall with plywood - to then mount various bike racks etc, and not worry about the white wall getting dirty or plasterboard chips etc.

Is this as simple as it sounds (screw some plywood sheets on top of the plasterboard) - or do I need to consider air gaps/other things which make it more involved? I don't really want to remove existing plasterboard/walls etc.

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#3338399 2-Feb-2025 23:03

Yes its Easy just make sure you mark out where studs are so its solid and attached. Don't skimp on the Ply thickness or the screws to attach it.

SepticSceptic

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#3338402 2-Feb-2025 23:54

Is the floor unfinished concrete ?

Not sure if this is an actual issue, but possible moisture wicking up from unsealed concrete?

Perhaps a 5mm gap between the bottom of the ply and the concrete ?

phrozenpenguin

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#3338403 2-Feb-2025 23:56

shrub:

Yes its Easy just make sure you mark out where studs are so its solid and attached. Don't skimp on the Ply thickness or the screws to attach it.

Thanks. Was thinking 18mm, although interested in feedback.

phrozenpenguin

842 posts

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#3338404 2-Feb-2025 23:57

SepticSceptic:

Is the floor unfinished concrete ?

Not sure if this is an actual issue, but possible moisture wicking up from unsealed concrete?

Perhaps a 5mm gap between the bottom of the ply and the concrete ?

Floor is unfinished concrete but with a carpet. Might do an epoxy paint job instead of carpet if I get the time. Thinking further, there is already a skirting board, so maybe I just mount the ply to be flush with that which keeps it safely off the floor.

johno1234

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#3338417 3-Feb-2025 07:17

The ply need not touch the floor and the skirting will hide this gap.

You can smash any holes you like the gib as it’s a good chance to move and add all the power and data points you could ever need.

Forget about useless stud finders. Use a powerful magnet to find the screws in the gib - it’s way faster and foolproof.

johno1234

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#3338419 3-Feb-2025 07:20

And 18mm? Not sure you need that and it will be heavy and expensive. Ply is very strong I’m sure 12mm would be more than enough.

eracode

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#3338422 3-Feb-2025 07:38

phrozenpenguin:

Floor is unfinished concrete but with a carpet. Might do an epoxy paint job instead of carpet if I get the time. Thinking further, there is already a skirting board, so maybe I just mount the ply to be flush with that which keeps it safely off the floor.

Partly depends on how you want it to look. 18mm ply may look a bit funny sitting on top of the skirting (because the skirting is probably ~18mm) - you'll lose some of the tidy appearance of the skirting - less so with 12mm ply. For a really tidy job I would carefully remove the skirting then put it back once the ply is up. Then it doesn't matter what thickness ply you use - but I agree 18mm is probably overkill in terms of weight, strength and cost.

There's probably a scotia at the top too?

Sometimes I just sit and think. Other times I just sit.

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mrdrifter

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#3338424 3-Feb-2025 07:42

As others have said 18mm is super thick, It's what I've built climbing walls with, so if that's on the plan, then definitely! 12mm with a nice front face should be more than sufficient.

I would pop the skirting off, leave a gap at the bottom of the ply, then stick the skirting back over it to hide the gap

shrub

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#3338521 3-Feb-2025 11:13

12mm should be good enough unless your planning on hanging a lot of weight off it? 18mm you can hang anything off. as others have said remove skirtings 1st leave a 10mm gap to floor then put back on to keep it looking tidy. Top edges can be tricky to keep straight but a nice bit of trim can cover that.

wellygary

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#3338533 3-Feb-2025 11:46

shrub:

12mm should be good enough unless your planning on hanging a lot of weight off it? 18mm you can hang anything off.

If you use 12mm and want to hang a specific heavy item, then just screw a long 2*4 onto the ply to spread the load and hang it from that...

neb

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#3338589 3-Feb-2025 14:30

wellygary: If you use 12mm and want to hang a specific heavy item, then just screw a long 2*4 onto the ply to spread the load and hang it from that...

That's what we did with the bike holder. Actually it was something like 100x25 with extra screws into the nogs on the sides of the stud, since the bike swings back and forth and a single line down the stud would have been iffy.

johno1234

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#3338604 3-Feb-2025 15:12

If you wanted to save time and money on the pretext of artistic flair - instead of covering the whole wall, you could install a set of ply 1200x600 feature panels on the wall and then use those to attach whatever you want. Would be a while lot easier as no joining up edges. Just bevel off the edges and screw them into the studs at regular spacing.

Feature wall panels

neb

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#3338608 3-Feb-2025 15:17

Speaking of appearances, even sanded ply has a very noticeable texture while plastered and painted gib is completely flat, in case that affects things in any way.

Jase2985

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#3338609 3-Feb-2025 15:27

My garage with 12mm ply shown below, with skirting and corner mouldings, no skirting on the back wall as I installed cabinets there. Quite hard to see as its all pine.

It does tidy it up as otherwise you are left with the edges of the sheets which arent always even.

The ceiling is on isolated rondo battens.

pdh

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#3338616 3-Feb-2025 15:35

I did this in my garage - when building a new house a couple of years ago.

Bunnings does a very good line of non-structural ply (often from Brasil) - which has a really nice surface for paint or 'varnish'.
At about 55$ (12mm) or 100$ (18mm) a full sheet, non-structural simply means it hasn't paid for the testing to get NZ certified.
I would be a complete waste of money to use structural/certified - and obviously doesn't need to be tanalised (for an internal space).

I used one coat of a cheapish urethane, which helps with dust/cobwebs and looks pretty.

Leave your existing plasterboard alone (just screw ply over it) - as it was likely required for your earthquake bracing.

As others have said, 12mm is OK for small stuff, for bikes you'll want 18mm - or a local stiffener.

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