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Wall rock thermal liner

Hk folks
I have some wallrock thermal liner to hang later in the year. Has anyone used it and if so can you give any heads up? The customer wants to paint straight over it.

Got you covered there, pardon the pun There is a video 2/3 down the page with all you need to know, including how to produce a really nice finish for painting. The customer can decide if his idea is best or not!

Hi Andy
Thanks for that, I had heard that one needs to line over the insulation covering. The job is for a designer friend and I am not sure it will fix their issue, its a garden room with more than 50% windows with ineficient heating. I mentioned to her that it needs lining over the top but she is confident that it won’t need that! What can you do when the advice you offer is not heeded?
She has researched the product but I feel that its clutching at straws in this situation.
The wall rock paper in general is ok but falls in opinion when going round curves in ceilings etc. And the textured surface lets it down IMHO. I prefer to use conventional 1000 or 1200 and scrim tape deep cracks. I have witnessed decs who think that the wall rock is good to cover imperfections with ou filling and it falls well short of performing that task. However the thickness of the insulator looks more likely to.


I would advise your client to have it lined with the fibreliner, otherwise if it gets caught or knocked it will puncture.
I always cross-line with the fibre liner and butt joint Don’t fill joints, because any movement in the thermal liner will cause the joints to crack!
You can also buy fibre liner plus now which has a lot smoother finish for painting over.
However, if your going to use standard fibre liner, apply a coat of chosen paint and leave to dry then lightly abrade with 320g abranet (machine sand if you want)but no heavy hands, then two full coats. The fibres in the face of the fibre liner get pushed about and raised so you end up with flashing against your cutting in and rollering. If you sand with 320g after first coat this flattens the fibres and gives a good base for further coats. The fibre liner plus is much smoother and you tend not to have this problem but I would do it anyway for belt n braces procedure.

Also if your going over old emulsion paints always coat the wall with a decent sealer such as Zinsser Gardz or Shieldz as the adhesive for the fibre liner and thermal liner is far too strong for the weight of the wall covering and can attack the underlying substrates causing joints to fail.

I have installed the Thermal & Fibre liners on several occasions and it does make the walls feel warmer and improves heat loss but I cant say its a sure fix to eradicate problematic damp and mould growth.

Hope this helps

1 Like

As always Russ that is very helpful.
Thank you

Russ has it covered.

On a curved ceiling, I agree that your approach is the most reliable Ciaran. I found that splicing the thermal liner was the way to make the curve. And then line over it as per normal. But I stopped at one proof of concept and would not use that option in that situation again.

I think the insulation science of thermal liner is a bit flawed, or at best marginal for saving on heating bills, but when something is warm to the touch, psychologically I guess you do feel “warm” even if your nose is dropping off?

Primarily I would view thermal liner as a no nonsense part of a solution to line standard rough walls. Over woodchip that is holding a ceiling up, and it just doesn’t make sense to pull the whole lot down again but you want to lose the texture and the 80’s look, this product is worth a look.

Hi Ciaran,
Sorry but I have just read this. Like Andy says, I always cross line using a fibrous liner, actually, fibrous liners are our standard liner.

In fact, I think you may find that on the Wallrock tech sheet, it does actually state that you should over line with a fibrous liner for painting. (Use their own liners)
Cheers and sorry to be late replying but just discovered this forum.