Trivia du jour - plasterboard

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Bob Mannix

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Jul 10, 2008, 3:53:26 AM7/10/08
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When I were young, I assumed that one plastered the dark side of
plasterboard and used the ivory side if you weren't skimming (note I said
"assumed", 'assumption is the mother of all cock-ups' etc...). As I matured
I came to the conclusion you could skim either side but used to skim the
dark side still.

I note now that manufacturers carefully stamp "plaster other side only" on
the dark side (ie you must use the ivory side).

Don't really want a huge flame of indignation (but it is uk.d-i-y, that's
kind of a given :o) ). Two questions:

1. Have I been wrong all this time?
2. What is the *manufacturer's* reason for insisting you plaster the ivory
side?

--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)


Rod

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Jul 10, 2008, 4:43:06 AM7/10/08
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Yes - you have. (But so was I.)

The plaster within is guaranteed to be hard up aginst the white paper.
(I think it must be on the bottom when they make it.) There can be air
bubbles, etc. just inside the dark side. (Cue Pink Floyd.) You also get
the turnover bits on that side - so absorbancy will vary across the
sheet and be least (I think) nearest the board edges. There might be a
difference in the actual paper/card layer which is significant - but I
don't know.

Saw a film about plasterboard making - maybe one utube or somewhere?

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
<www.thyromind.info> <www.thyroiduk.org> <www.altsupportthyroid.org>

Andy Wade

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Jul 10, 2008, 6:28:31 AM7/10/08
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Rod wrote:

> Yes - you have.

I disagree. It *definitely* used to be the case that the grey side was
for skimming and the ivory side for painting or papering directly.

Why it's changed I have no idea.

--
Andy

Rod

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Jul 10, 2008, 6:47:45 AM7/10/08
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I agree that is what I was told (a long time ago), but I have come to
suspect that I have always been wrong.

My earlier point about double-layer of paper is picked up in this Q&A
from BG's site:


Q: Can British Gypsum clarify their position regarding the skimming of
Gyproc plasterboard?

A: Skimming should be carried out on the front of the board (ie. the
face with no paper overlap). In the case of Gyproc Wallboard this is the
ivory face. This advice also applies to Fireline, SoundBloc and Duraline.

<http://www.british-gypsum.com/support/questions_and_answers/qa007.aspx>

But I was never trained and didn't research then - it was just what I
picked up from friends and acquaintances. So the argument/advice might
indeed have turned upside down over the years.

Bob Mannix

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Jul 10, 2008, 8:38:59 AM7/10/08
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"Andy Wade" <spamb...@maxwell.myzen.co.uk> wrote in message
news:6dm6ifF...@mid.individual.net...

> Rod wrote:
>
>> Yes - you have.
>
> I disagree. It *definitely* used to be the case that the grey side was
> for skimming and the ivory side for painting or papering directly.
>

Can you honestly remember where you read it or who it was who told you and
what authority *they* had? I only ask because I used to think like you but,
when it came to it, I couldn't prove to myself I hadn't just assumed it!

Phil L

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Jul 10, 2008, 8:49:33 AM7/10/08
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One side of the board is completely wrapped in paper, that is to say, two
sheets of paper are used to make the board and one of them (the one that
should be plastered) is wider than the other, so that it covers one side
completely and goes around each edge and onto the opposite side by about an
inch.
Then the backing paper is stuck on after, to form the other side of the
board, and also to cover the edges of the paper that we've just mentioned.

In theory, if you plastered the backing paper, it /could/ peel away from the
body of the plasterboard because it's only held in place by the plaster
within the board, in reality this is probably never going to happen, unless
it gets *really* steamy, perhaps in a bathroom or kitchen that is in use
almost constantly.


Bob Mannix

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Jul 10, 2008, 9:08:08 AM7/10/08
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"Phil L" <neverc...@hotmail.com> wrote in message
news:xzndk.24282$E41....@text.news.virginmedia.com...

Thanks you. That's both believable and sensible! Was this always the method
of construction or was the failure mode ignored until now?

dennis@home

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Jul 10, 2008, 2:05:11 PM7/10/08
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"Bob Mannix" <b1o...@mannix.org.uk> wrote in message
news:g54vt4$fqa$1...@south.jnrs.ja.net...

The plaster board I used last had the words plaster this side on it, but I
can't recall the colour.

Andrew Gabriel

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Jul 10, 2008, 6:12:03 PM7/10/08
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In article <g54f5n$b3c$1...@south.jnrs.ja.net>,

"Bob Mannix" <b1o...@mannix.org.uk> writes:
> When I were young, I assumed that one plastered the dark side of
> plasterboard and used the ivory side if you weren't skimming (note I said
> "assumed", 'assumption is the mother of all cock-ups' etc...). As I matured
> I came to the conclusion you could skim either side but used to skim the
> dark side still.
>
> I note now that manufacturers carefully stamp "plaster other side only" on
> the dark side (ie you must use the ivory side).
>
> Don't really want a huge flame of indignation (but it is uk.d-i-y, that's
> kind of a given :o) ). Two questions:
>
> 1. Have I been wrong all this time?

No - it changed about 25 years ago when we started importing
significant amounts of plasterboard, and the UK had been at
odds with the rest of the world.
(This was covered on my plastering course.)

> 2. What is the *manufacturer's* reason for insisting you plaster the ivory
> side?

Ivory side is quality controlled with regards to absorbency, to
give consistent results when plastered (or painted). Brown side
isn't and different boards might behave differently.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

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