Hi Folks,
Okays, I have done some searches, but nothing definitive has appeared, hence
this post.

Our bathroom has an adjoining "cubicle" area which (I guess) was designed as
a shower
cabinet (all three walls of the cubicle are solid block walls; the cubicle
is accessible from
the bathroom proper).
There used to be a shower installed in there, but to reduce the height a
false pine ceiling (tongue and groove) was installed hence isolating a
cuboid space of
about two feet in height above the shower.
This false ceiling comprised of a perimeter of two-by-two wood, a strap
across the middle and
the 10mm pine boards nailed up to this frame.

We are refurbishing the whole bathroom, hence my curiosity got the better of
me and thus I
decided to remove the false pine ceiling.
The plasterboard ceiling above the (now removed) false ceiling was painted a
Barbie Pink
colour, but it also was significantly covered in black mould.

I plan to remove this plasterboard (taking precautions not to breathe the
ensuing dust) and
reinstate it. I plan to install a vapour barrier above the new plasterboard
first.

When I showed a friend this present state of ceiling and explained what I
planned to do,
he mentioned that the addition of a vapour barrier was
more likely to induce such fungal growth than if I didn't install one.

I wonder if he's right (hence this post): would it not be true that adding a
vapour barrier
prevents the dissemination of humid air hence the humidity is higher within
the bathroom?
Or is this a half-truth: in the absence of forced ventilation it is true
that no vapour barrier
is better than a vapour barrier?

I'm no expert at this, hence it's time to humbly engage the collective
wisdom of the group.

Thanks in advance

Mungo

Mungo Henning wrote:
Hi Folks,
Okays, I have done some searches, but nothing definitive has appeared, hence
this post.

Our bathroom has an adjoining "cubicle" area which (I guess) was designed as
a shower
cabinet (all three walls of the cubicle are solid block walls; the cubicle
is accessible from
the bathroom proper).
There used to be a shower installed in there, but to reduce the height a
false pine ceiling (tongue and groove) was installed hence isolating a
cuboid space of
about two feet in height above the shower.
This false ceiling comprised of a perimeter of two-by-two wood, a strap
across the middle and
the 10mm pine boards nailed up to this frame.

We are refurbishing the whole bathroom, hence my curiosity got the better of
me and thus I
decided to remove the false pine ceiling.
The plasterboard ceiling above the (now removed) false ceiling was painted a
Barbie Pink
colour, but it also was significantly covered in black mould.

I plan to remove this plasterboard (taking precautions not to breathe the
ensuing dust) and
reinstate it. I plan to install a vapour barrier above the new plasterboard
first.

When I showed a friend this present state of ceiling and explained what I
planned to do,
he mentioned that the addition of a vapour barrier was
more likely to induce such fungal growth than if I didn't install one.

I wonder if he's right (hence this post): would it not be true that adding a
vapour barrier
prevents the dissemination of humid air hence the humidity is higher within
the bathroom?
Or is this a half-truth: in the absence of forced ventilation it is true
that no vapour barrier
is better than a vapour barrier?

I'm no expert at this, hence it's time to humbly engage the collective
wisdom of the group.

Thanks in advance

Mungo


I think he is likely right.

What you need is a vapopur barrier immediately above the false ceiling,
not a nice void that traps moist air above it.

OTOH if the false ceiling is staying out, then you should use a vapour
barrier at that point AND a bathroom fan..

I covered my enclosed shower ceiling with ply then ,then glued some upvc
sheet, sealing the edges with upvc quandrant beading and silicone.,very neat
and no mould