Following a roof leak that went undetected for months, we suspect the fibreglass slab insulation in the cavity wall has been saturated for some time.

We've been advised to have it all removed and replaced because of mold spores, although this would involve removing at least part of one skin of the wall.

Is replacing it really necessary or will it dry out on its own and any mold spores not be a problem?

On 09/07/2016 22:58, mike wrote:
Following a roof leak that went undetected for months, we suspect the
fibreglass slab insulation in the cavity wall has been saturated for
some time.

We've been advised to have it all removed and replaced because of
mold spores, although this would involve removing at least part of
one skin of the wall.

Who advised you to do this?

Is replacing it really necessary or will it dry out on its own and
any mold spores not be a problem?

Given there should be a vapour barrier between your plaster and your
insulation I don't see how these spores should enter your house?

On Saturday, 9 July 2016 22:58:07 UTC+1, mike wrote:
Following a roof leak that went undetected for months, we suspect the fibreglass slab insulation in the cavity wall has been saturated for some time.

We've been advised to have it all removed and replaced because of mold spores, although this would involve removing at least part of one skin of the wall.

Is replacing it really necessary or will it dry out on its own and any mold spores not be a problem?

Best to suck it and see.
Don't rush into instant action.
There is nothing for mould to sustain itself on.
The air is full of mould spores anyway.
The problem may well be self resolving, this possibility is one that's been anticipated.

The fibres are treated with a moisture repellent so should not be as wet as you might think. In practice water runs through it rather than remaining caught in the insulation.

On 10/07/2016 00:31, Fredxxx wrote:
On 09/07/2016 22:58, mike wrote:
Following a roof leak that went undetected for months, we suspect the
fibreglass slab insulation in the cavity wall has been saturated for
some time.

We've been advised to have it all removed and replaced because of
mold spores, although this would involve removing at least part of
one skin of the wall.

Who advised you to do this?

Is replacing it really necessary or will it dry out on its own and
any mold spores not be a problem?

Given there should be a vapour barrier between your plaster and your
insulation I don't see how these spores should enter your house?

If fitted/fitted correctly.

My concern would be the moisture wicking through an internal wall, and a
cycle of decorating and damp control until it dries out. A couple of
pilot holes should tell you how wet the internal skin is.

--
Cheers, Rob

However, its not going to dry very fast and not be much of an insulator is
it?

Brian

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This newsgroup posting comes to you directly from...
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"Fredxxx" wrote in message
...
On 09/07/2016 22:58, mike wrote:
Following a roof leak that went undetected for months, we suspect the
fibreglass slab insulation in the cavity wall has been saturated for
some time.

We've been advised to have it all removed and replaced because of
mold spores, although this would involve removing at least part of
one skin of the wall.

Who advised you to do this?

Is replacing it really necessary or will it dry out on its own and
any mold spores not be a problem?

Given there should be a vapour barrier between your plaster and your
insulation I don't see how these spores should enter your house?

On Saturday, 9 July 2016 22:58:07 UTC+1, mike wrote:
Following a roof leak that went undetected for months, we suspect
the fibreglass slab insulation in the cavity wall has been saturated
for some time.

Can you drill a few holes in the outer skin and blow some air through the cavity to dry the stuff out?

Owain

On 09/07/16 22:58, mike wrote:
Following a roof leak that went undetected for months, we suspect the fibreglass slab insulation in the cavity wall has been saturated for some time.

We've been advised to have it all removed and replaced because of mold spores, although this would involve removing at least part of one skin of the wall.

Is replacing it really necessary or will it dry out on its own and any mold spores not be a problem?


a) It will eventually dry out - but it might take quite a long time;

b) Mould? Who told you that? Seems like some panicky knee jerk reaction
to me. Even IF it goes mouldy (unlikely - rockwool is not known for
being nutritious to any lifeforms), how are the spres got to get through
the inner wall skin?

mike wrote:
Following a roof leak that went undetected for months, we suspect the
fibreglass slab insulation in the cavity wall has been saturated for
some time.

We've been advised to have it all removed and replaced because of
mold spores, although this would involve removing at least part of
one skin of the wall.

Is replacing it really necessary or will it dry out on its own and
any mold spores not be a problem?


Utter garbage. Fibreglass cavity insulation, whether slab form or blown wool
is treated with silicone so that water runs off it - it doesn't become
waterlogged like loft fibreglass would.

Someone's trying to make a few grand from you for work that doesn't need
doing. It will dry out in it's own time, almost all the cavity insulation in
the country gets wet on occasion - it's designed with this in mind - no harm
will come to it or your house. The mould fairy tale is just that - a scare
tactic invented to get you running to the bank to throw money at something
that doesn't exist.

Fredxxx wrote:
On 09/07/2016 22:58, mike wrote:
Following a roof leak that went undetected for months, we suspect the
fibreglass slab insulation in the cavity wall has been saturated for
some time.

We've been advised to have it all removed and replaced because of
mold spores, although this would involve removing at least part of
one skin of the wall.

Who advised you to do this?

Is replacing it really necessary or will it dry out on its own and
any mold spores not be a problem?

Given there should be a vapour barrier between your plaster and your
insulation I don't see how these spores should enter your house?

Vapour barrier? - there's no vapour barrier when blown wool is installed,
and I've never even heard of a vapour barrier being used or even advised
when using batts. It's never been on any plans that I've seen

RJH wrote:
On 10/07/2016 00:31, Fredxxx wrote:
On 09/07/2016 22:58, mike wrote:
Following a roof leak that went undetected for months, we suspect
the fibreglass slab insulation in the cavity wall has been
saturated for some time.

We've been advised to have it all removed and replaced because of
mold spores, although this would involve removing at least part of
one skin of the wall.

Who advised you to do this?

Is replacing it really necessary or will it dry out on its own and
any mold spores not be a problem?

Given there should be a vapour barrier between your plaster and your
insulation I don't see how these spores should enter your house?

If fitted/fitted correctly.


There's never been a need for vapour barrier installed with fibreglass batts

My concern would be the moisture wicking through an internal wall,
and a cycle of decorating and damp control until it dries out. A
couple of pilot holes should tell you how wet the internal skin is.

On Sunday, July 10, 2016 at 2:31:18 PM UTC+1, Tim Watts wrote:

a) It will eventually dry out - but it might take quite a long time;

b) Mould? Who told you that? Seems like some panicky knee jerk reaction
to me. Even IF it goes mouldy (unlikely - rockwool is not known for
being nutritious to any lifeforms), how are the spres got to get through
the inner wall skin?

We were told this by a building company that specialises in damp and remedial work for insurance companies.

I thought it sounded like someone trying to talk the job up which is why I asked. The consensus seems to be that it's exactly that.

Thanks for all the replies.

On 10/07/16 16:09, mike wrote:
On Sunday, July 10, 2016 at 2:31:18 PM UTC+1, Tim Watts wrote:

a) It will eventually dry out - but it might take quite a long
time;

b) Mould? Who told you that? Seems like some panicky knee jerk
reaction to me. Even IF it goes mouldy (unlikely - rockwool is not
known for being nutritious to any lifeforms), how are the spres got
to get through the inner wall skin?

We were told this by a building company that specialises in damp and
remedial work for insurance companies.

There you go - they are talking cobblers trying to drum up work.


I thought it sounded like someone trying to talk the job up which is
why I asked. The consensus seems to be that it's exactly that.

Thanks for all the replies.

On 09/07/2016 22:58, mike wrote:
Following a roof leak that went undetected for months, we suspect the fibreglass slab insulation in the cavity wall has been saturated for some time.

We've been advised to have it all removed and replaced because of mold spores, although this would involve removing at least part of one skin of the wall.

Is replacing it really necessary or will it dry out on its own and any mold spores not be a problem?

Cavity insulation batts are treated with a water repellent to prevent
them soaking up water (unlike loft insulation which will become
waterlogged, like a wool pullover).

The outer skin of the house should breathe anyway. If you are worried
fit some airbicks just above the DPC and some at eaves level.

On 11/07/16 12:08, Andrew wrote:
On 09/07/2016 22:58, mike wrote:
Following a roof leak that went undetected for months, we suspect the
fibreglass slab insulation in the cavity wall has been saturated for
some time.

We've been advised to have it all removed and replaced because of mold
spores, although this would involve removing at least part of one skin
of the wall.

Is replacing it really necessary or will it dry out on its own and any
mold spores not be a problem?

Cavity insulation batts are treated with a water repellent to prevent
them soaking up water (unlike loft insulation which will become
waterlogged, like a wool pullover).

The outer skin of the house should breathe anyway. If you are worried
fit some airbicks just above the DPC and some at eaves level.

The paragraph above says it all.

Porous brick/bock walls will breathe and dry out.

The vapour barrier (if any) will be on the inside

Given that the leak went undetected, one can presume no signs of
internal wall damp were seen.



--
Those who want slavery should have the grace to name it by its proper
name. They must face the full meaning of that which they are advocating
or condoning; the full, exact, specific meaning of collectivism, of its
logical implications, of the principles upon which it is based, and of
the ultimate consequences to which these principles will lead. They must
face it, then decide whether this is what they want or not.

Ayn Rand.

On 10/07/2016 16:09, mike wrote:
On Sunday, July 10, 2016 at 2:31:18 PM UTC+1, Tim Watts wrote:

a) It will eventually dry out - but it might take quite a long time;

b) Mould? Who told you that? Seems like some panicky knee jerk reaction
to me. Even IF it goes mouldy (unlikely - rockwool is not known for
being nutritious to any lifeforms), how are the spres got to get through
the inner wall skin?

We were told this by a building company that specialises in damp and remedial work for insurance companies.

No surprise there then.

A 1960's ex-council house behind me had the full scaffold treatment
recently with a complete cover over the roof. Nothing hapened for 2
weeks then some guys spent a couple of days removing a few tiles
(Marley modern on a 37 degree pitch), did a couple of hours of hammering
and banging and that was it.

I have since heard that the felt had been damaged and a cracked
tile allowed water to soak into the loft insulation and rot the
trusses a bit. Apparently the owner claimed on her insurance when
a damp patch appeared in a bedroom ceiling and the Ins. Co. paid
out £6,000 (!!!!) to 'repair' it. This work could have been done
during a dry spell and taken no more then 2 to 3 days.

She's going to have a shock when her renewal premium is due.