Stephen McNeil, senior building physicist at BRANZ, joined Peter Wolfkamp to chat all things mould.
They discussed the state of New Zealand homes, what makes them so susceptible to mould, and how to fix it.
LISTEN ABOVE
See omnystudio.com/listener for privacy information.
Listen
Watch
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:06):
You're listening to the Resident Builder podcast with Peter Wolfcamp
from News Talk SEDB.
Speaker 2 (00:12):
Right, it is nine minutes after eight, and it's my
great pleasure, I think for the first time on the
show to have a I know I've met Steve over
the years, but to have you on the show, doctor
Steve McNeil, a very good morning or to your friends,
doctor mold how does that work?
Speaker 3 (00:29):
Thanks better.
Speaker 2 (00:32):
Pleasure, Hayle. Let's start at the beginning. Brands as part
of their Like most people, I think when they think
about brands, think about brand's appraisals on a tube of
sealant or a building product or something like that. But
there's I know, there's a lot more that goes on,
including this sort of long term or longitudinal studies of
(00:53):
like real houses with real people living in them. Is
that part of the work that you've been involved in.
Speaker 3 (00:59):
Yeah, yeah, definitely, Petter. So so if you look at
the long term sort of the long name of brands
that's Building Research Association YEA Celands. There's a really strong
research component to what we do. And so I've been
part of a team that's recently just finished a really
large piece of field work called Heat two so that's
a survey of around seven hundred and fifty homes in
(01:21):
the country. We've had really really detailed both energy, temperature,
humidity monitoring of people's homes, yes, over the course of
twelve months, so it's really quite detailed work with a
whole part of different surveys as well, so you know,
asking all the questions aroount how people are using their homes,
how they're experiencing over heating and experiencing damp and mold
(01:43):
and those kind of things. And one of the one
of the really you know, astounding findings from that is,
you know, fifty percent of our homes have visible mold
greater than any four piece of paper. So it's it's
quite a large amount.
Speaker 2 (01:56):
So when you say an so that's a patch of
mold that's visible on walls and ceilings that would be
as large as a piece of a four.
Speaker 3 (02:05):
Paper Yeah, yep, and it's it's you know, one of
these things that can be quite a health risk as
well obviously, but you've also got damage to the building
longer term to think about. Yeah. Like I said, it
was the second edition of this heat study, so we
did an earlier one and finished around two thousand and
(02:27):
one I think it was. And if you look at
what we saw on bedrooms overnight from that study, we
were seeing around an average of thirteen degrees as the
temperature of the bedroom. That's changed recently to around sixteen
degrees in this survey. And we think a large part
of that is, you know, you got things like warm
up heavy homes happening, so more insulation going in. But
(02:48):
also if you look at the original heap from near
the early two thousands, in the sample of four hundred homes,
it was about four heat pumps, right, and now it's
about sixty percent of buildings have heat pumps. So we've
got a lot more efficient heating in our homes than
what we've what we had back.
Speaker 2 (03:07):
So I mean, look, part of this is really good
to hear. Like the numbers are still not great. If
it's fifty percent of houses, that's not great. But I
think for those of us who have been in this
space for a while, I'll just speak for myself, we
tend to have kind of a quite negative approach to
housing in a sense that we go, we know what
all the faults and failures are. But it is genuinely
(03:29):
good news to hear that in some cases some New
Zealand houses are actually quite a number of them are
better than they were twenty years ago.
Speaker 3 (03:40):
Yeah, and it's probably more a case of well, the
way people are using their homes to change it and
they've got access to easy to use heating. I think
we've still got a huge number of homes that need
a lot of work, you know, the retrofit side of
office what we have in the country. So if you
look we've got sort of around I think it's about
too million properties. Look at the last that's indeed data
(04:01):
and usually on two million private dwellings. If you look
at sort of the last screw maybe the last twenty
years of buildings that have got double glazing and you know,
some form of insulation that leaves a huge amount you
know that that are going to be single glazed problems,
missing insulation walls, and it's of the scale that the
building you know, the industry can't build its way on
that problem. We can't replace those buildings. The capacitive you know,
(04:24):
industry running at full capacity would take decades to get
through that level of work. So it would have to
be a retrofit kind of scenario to to really improve
some of these older stocks, and of.
Speaker 2 (04:35):
Course some of that retrofit work is quite extensive, you know,
Like arguably, you could go, hey, look, if i've got
single glazing, it's kind of low hanging fruit. Right in
most cases, probably ninety five percent of cases, it's it's
a relatively straight forward process to go, I'm going to
take that single glazing out. I'm going to retrofit some
double glazing into that space. But once we reach walls
(04:58):
and hard to reach underfloor areas and so on, it
becomes a little bit more challenging. So the lack of
insulation is that in and of itself a reason that
we have so much mold in our houses.
Speaker 3 (05:10):
Yeah, that's one of the major contributors. And also ventilation
as well as a big one. Yep. So I mean,
if you look at what happens on the inside surface
of a building, that's really controlled by the way people
are living and what those surface seperatures are. And so
that's that's down to your heating and ventilation and your
level of insulation, and that doesn't get into the space
(05:31):
where what's happening inside the building cavities as well, So
what's happening inside roof spaces for example, where we're seeing
increased reporting of moisture and roofs yep in recent in
recent years. So yeah, the insulation is a big part
of it, but we also need to be mindful that
we really have to ventilate well. You know, as a nation,
we've never really done it that well. We've just kind
(05:52):
of got away with it with buildings that are relatively leaky. Yes,
but now we're at the point where you know, we're
building a little bit more air tight, which is great
for keeping heating, but it's really exposing that we're not
ventilating properly, and it's it's something that we're trying to
address at the moment.
Speaker 2 (06:07):
And so our code requirements around ventilation is it's a
bit out a date to be blunt.
Speaker 1 (06:16):
That's that would be my.
Speaker 3 (06:17):
Opinion of it. Yeah, yeah, five percent the floor area
if I open the windows, basically as your typical compliance
pathway for domestic drillings, and we seriously need some compliance
pathways for say mechanical ventilation that allows the industry to
actually grow. You know, it's establish a good set of
rules around it, make sure it gets done well. But
(06:38):
that's that's you know, the sort of thing that's definitely
happened overseas and it makes a big difference to health productivity,
all those things.
Speaker 2 (06:47):
Can I start with, I don't know, we've already been chatting,
but just a question what is mold like? If you
have to say what not so much how does it
get there? But what actually is it? If I go
in and I, you know, go to the back of
the wardrobe and I find that there's a blackish patch
on the plaster board, what actually is it?
Speaker 3 (07:07):
It's a it's a living organism, it's a it's a fungus.
It's yeah, it's and it's not actually the presence of
it on the wall that's really the big issue for people.
It's it's it's what comes off and gets into the air.
It's the spores that get into the air and those
kinds of things that are really the thing that that
has a health impact.
Speaker 2 (07:26):
Right, So people when they talk about mold, will will
talk about you know, stacky botros So is that a
particular type of mold and is that particularly hazardous to
human health?
Speaker 3 (07:39):
Yeah, that that's probably one of the worst ones we've
got around, and that was prevalent in a lot of
the leaky buildings where you have a large amount of
water that was accumulating inside walls that that can be
quite toxic.
Speaker 2 (07:50):
Yes, and how is it that that develops? And you know, like,
how do you like, do you get a good mold?
Probably not, but you get one that's not inurious.
Speaker 3 (08:00):
To pensylm was derived from from molds. You know there
are there are good mold out there, but yeah. It's
the funny thing is people say, you know, associated only
with with condensation, and that's one thing to be to
be wary of. So mold will actually grow when the
relative humility gets above about eighty percent. So it's it's
(08:22):
one of these things that if it stays wet enough
for long enough on a surface or damp enough, it
doesn't have to be actually you know physical water drops there. Yes,
it can, it can, it can start to grow. If
it gets too cold, it will slow down. So that's
really really cold spaces will not tend to grow it.
(08:42):
And it's you know, if you look at the sort
of there's a few technical teams I won't check out there,
but when when you when you increase that relative unity
even more, that the rate of growth speeds up quite
a lot. Right. For example, if you were if it
was around eighty percent, you know, on a surface for
for a month, you'll you start to see some mold.
(09:02):
But if it was around ninety five percent, you see
for some species you'll see mold with it a few days.
Speaker 2 (09:07):
And look, I was at a presentation the other day
where they had sort of a twelve month serve a
relative humidity for Auckland, Wellington and christ Church. Auckland regularly
for an extended period of time was above ninety percent
relative humidity.
Speaker 3 (09:23):
Yep. And that's also the danger when you're when you're
looking at just look at relativity and without taking temperaure
into account. Right, So when you bring that outside air
at relativity into your house, you change the temperture of
it so that that actually changes the relative humidity. So
it's not as bad as saying that Auckland's always going
to be ninety five in the building, because the change
(09:45):
in temperature will change what that relative mumidity is. Yes,
But the thing is it is high enough in Auckland
that for I think it's it's thirty percent of the
year fortydred percent of the year that it is wetter
outside than you would like inside. If you're trying to
keep the rh between forty and sixty percent under a
normal temperature. Yep. Absolutely, it's it's a big problem for
(10:09):
Auckland especially, and are anywhere really north of about your
Plumbus and Hamilton. Yep. It becomes more and more of
an issue because you're at this place where you're relying
on dilution as your primary means of getting rid of
that moisture. But if the air that you're diluting it
with through outside has got plenty of moisture in it,
(10:30):
you're You're you're in a hidings nothing to actually get
rid of it.
Speaker 2 (10:32):
Sometimes it's a particular geographical challenge, isn't it for certain regions,
which I think we're only just starting to understand that.
It's it's like we're in an environment where it's because
you can't change the relative humidity outside, right, there's nothing
we can know about that. No, we're not changing the
climate in these areas, but we are going to have
(10:53):
to learn to deal with it. So I'm going to
take a short break. I'm going to come back, and
what I'd really like to do is go, okay, so
if you fifty percent of our houses have got visible
mold the size of an a four bit of paper.
What do we do as homeowners as tenants? You know,
what are the things that because I think some of this,
if we're really honest, is operate error, right, a lack
of awareness, and so we're not using our houses right
(11:17):
in order to control the.
Speaker 1 (11:18):
Mold news talk zibby with.
Speaker 2 (11:22):
Me this morning, doctor Steve McNeil from Brands or Dr
Mold to his mates. So we've got a house. We
know that. You know the surveys out there right, seven
hundred and fifty houses long term survey, fifty percent of
them reporting mold as occupants, whether we own it, whether
we rent it? What do we do? Like basic things
that we should all be doing.
Speaker 3 (11:44):
Basic things. You really need to make sure that you're
trying to control the moisture sources in the building. Yes,
you try and try and draw your clothes outside if
you can. If you can't, make sure we're using a
dryer that's been to to outside the other option, but
that obviously comes with the power cost yep uh. The
(12:07):
The other thing is, you know, really really basic stuff
like you know, using pots on on on on the stove,
all those using listing pots on the stove for example,
though those things are are dead simple and they can
they can seriously decrease the metamorshure that that you're pumping
out into the building. But also, you know, keeping on
top of ventilating the building properly as well is a
(12:28):
good thing. One thing that's that's that feels a bit counterintuitive,
but the whole practice of the German practice of what
they call shop ventilation, where you go around and you
just open up all the windows first thing in the
morning and then close them and do that kind of
thing every every few hours. If if you don't have
a ventilation system, that that's a perfectly adequate way to
help deal with with some of that load. You know,
(12:51):
we can't have we can't have everyone, you know, living
in a perfect house. You have to deal with what
you have, Yes, exactly. I think that that that's quite
a practical step. And a really important thing for that
is when you when you open your windows stuff to
flush that that moisture out. Don't be afraid to do
that when the air is warm. Right, it sounds really counterintuitive,
(13:12):
but within you as long as it's only open for
a few minutes, yep. By the time you close the
windows again, but the heat has not left all of
the materials in the building, and that holds a lot
more heat than what the air was holding that you
just let out. If you're worried about comfort, just doing
a couple of minutes of everything wide open and closing
it again can actually be quite effective. So we resually
(13:35):
did a study in Wellington a few years ago with
a family in a pretty modern house that we're dealing
with connosation on the on the frames of their double
glaze one yes, and we measured some measured the conditions
and said, hey, look this is what it's like outside
if you just did this. And I think we went
from something like an eighty percent chance of finding real
(13:57):
to humidity of eighty percent to something like a forty
percent chance within a couple of weeks.
Speaker 2 (14:03):
And that literally is as simple as get up in
the morning. Maybe not at quarter past five when I
got up this morning, but get up in the morning,
you know, open the back door, open the front door,
open a couple of windows, let the air circulate through
the house for five minutes, ten minutes, close it up
again and then, like you say, the heat that's in
(14:24):
your walls and finish you're not losing that, you're just
using losing that moisture that's in the air.
Speaker 3 (14:31):
Yeah, I mean the heat capacity of all the materials
and you're building far exceeds what's in the air. You're
not doing it for too long, you know. I had
a study that we did a few years ago on
that ventation house that you came to visit, yes, where
we had one of the one of the new guys
was was was task was arriving every morning at exactly
eight o'clock and opening the windows conditioning conditioning in one
(14:52):
of the rooms to a particular temperature and humility. And yeah,
we learned some really interesting stuff from that, and it's
it is really that that short period and there's not
really much benefit of leaving it open for a long
long period after that, right unless your building get gets
warm from the sun. You know, you really need to
mobilize that moisture out of materials to get out of
(15:14):
the house. And so it can be an effective thing.
I mean, ideally year were to have everyone having you know,
hit recovery, mechanical ventilation, all that kind of stuff, but
you know that stuff that will take time for people
to eventually get The.
Speaker 2 (15:32):
Other day when I was talking with some of the team.
Speaker 3 (15:34):
There was.
Speaker 2 (15:37):
A simple two page advisory note that someone sent to
me from Brands Brand's Healthy Homes and it's basically about
temperature and humidity and so on. It's just a two pager.
It's really simple. It's bloody good information, to be fair.
I'm going to put a link up on my Facebook
page now or shortly if people want to read, you know,
(15:58):
if they want to go deep dive into this, this
information is available. How would you find the results for
the HEP two study.
Speaker 3 (16:06):
So that's all on the brand's website Brands dot dot
crodor In did and we are about to launch a
brand new one very soon, so within the next month.
I'm I'm sure it's within the next month. And so
that's going to make things a lot more easy to
find because it's that's always been a challenge with any website,
you know, you get more and more information, trying things
get gets more of a challenge. But there's been a
(16:26):
really good reorganization done. So that's that's about to go
go live very soon.
Speaker 2 (16:32):
Fantastic.
Speaker 3 (16:32):
So yeah, your your link, your link may change.
Speaker 2 (16:35):
Yeah, well I'll get this one out because it's a
really simple pdf. You know, print it off, put it
up at home and use it. Steve, thanks so much
for your time this morning. Actually, here's a quick text.
What if it's foggy, would you still open the house up? Yes,
you would.
Speaker 3 (16:51):
Yeah, if it's colder outside then it's inside. It's it's
gonna happless moisture in the air. Yep. The amount of
moisture in the air is very, very steeply dependent on
the temperature. Yes, so even if it's even by a
couple of get up.
Speaker 2 (17:05):
Open the doors and windows ten minutes, close them.
Speaker 1 (17:08):
Up, go for it.
Speaker 3 (17:10):
Like when it's when it's pouring down with the rain
and five degrees outside and you like, I don't want
to open the window. It's going to be one hundred
percent hourach outside. The thing is, though, that that year
that's only five degrees can can hold only a tiny
fraction of the moisture that right is in your building.
So it can still be quite effective at getting rid
of getting rid of moisture. Fantastic foggy and the same
(17:32):
temporature as your house. It's a different story.
Speaker 2 (17:34):
Okay, yeah, oh hey, look this is this has been fantastic.
We'll we'll get you back on and go take a
bit of a deep dive into this. But thanks and
thanks so much for joining us this morning.
Speaker 3 (17:45):
All right, thanks better.
Speaker 2 (17:46):
Been pleasure to take care Steve, your news talk s.
Let's get into the garden. Eight hundred and eighty ten
eighty four climb past. You can text as well nine
to nine two and I promise you before lunchtime today,
I'll put up this link for this pdf from Brands
on my Facebook page to just search for Resident Builder.
You can find the link for more from.
Speaker 1 (18:08):
The Resident Builder with Peter Wolfcamp. Listen live to Newstalk
ZB on Sunday mornings from six, or follow the podcast
on iHeartRadio
You're listening to the Resident Builder podcast with Peter Wolfcamp
from News Talk SEDB.
Speaker 2 (00:12):
Right, it is nine minutes after eight, and it's my
great pleasure, I think for the first time on the
show to have a I know I've met Steve over
the years, but to have you on the show, doctor
Steve McNeil, a very good morning or to your friends,
doctor mold how does that work?
Speaker 3 (00:29):
Thanks better.
Speaker 2 (00:32):
Pleasure, Hayle. Let's start at the beginning. Brands as part
of their Like most people, I think when they think
about brands, think about brand's appraisals on a tube of
sealant or a building product or something like that. But
there's I know, there's a lot more that goes on,
including this sort of long term or longitudinal studies of
(00:53):
like real houses with real people living in them. Is
that part of the work that you've been involved in.
Speaker 3 (00:59):
Yeah, yeah, definitely, Petter. So so if you look at
the long term sort of the long name of brands
that's Building Research Association YEA Celands. There's a really strong
research component to what we do. And so I've been
part of a team that's recently just finished a really
large piece of field work called Heat two so that's
a survey of around seven hundred and fifty homes in
(01:21):
the country. We've had really really detailed both energy, temperature,
humidity monitoring of people's homes, yes, over the course of
twelve months, so it's really quite detailed work with a
whole part of different surveys as well, so you know,
asking all the questions aroount how people are using their homes,
how they're experiencing over heating and experiencing damp and mold
(01:43):
and those kind of things. And one of the one
of the really you know, astounding findings from that is,
you know, fifty percent of our homes have visible mold
greater than any four piece of paper. So it's it's
quite a large amount.
Speaker 2 (01:56):
So when you say an so that's a patch of
mold that's visible on walls and ceilings that would be
as large as a piece of a four.
Speaker 3 (02:05):
Paper Yeah, yep, and it's it's you know, one of
these things that can be quite a health risk as
well obviously, but you've also got damage to the building
longer term to think about. Yeah. Like I said, it
was the second edition of this heat study, so we
did an earlier one and finished around two thousand and
(02:27):
one I think it was. And if you look at
what we saw on bedrooms overnight from that study, we
were seeing around an average of thirteen degrees as the
temperature of the bedroom. That's changed recently to around sixteen
degrees in this survey. And we think a large part
of that is, you know, you got things like warm
up heavy homes happening, so more insulation going in. But
(02:48):
also if you look at the original heap from near
the early two thousands, in the sample of four hundred homes,
it was about four heat pumps, right, and now it's
about sixty percent of buildings have heat pumps. So we've
got a lot more efficient heating in our homes than
what we've what we had back.
Speaker 2 (03:07):
So I mean, look, part of this is really good
to hear. Like the numbers are still not great. If
it's fifty percent of houses, that's not great. But I
think for those of us who have been in this
space for a while, I'll just speak for myself, we
tend to have kind of a quite negative approach to
housing in a sense that we go, we know what
all the faults and failures are. But it is genuinely
(03:29):
good news to hear that in some cases some New
Zealand houses are actually quite a number of them are
better than they were twenty years ago.
Speaker 3 (03:40):
Yeah, and it's probably more a case of well, the
way people are using their homes to change it and
they've got access to easy to use heating. I think
we've still got a huge number of homes that need
a lot of work, you know, the retrofit side of
office what we have in the country. So if you
look we've got sort of around I think it's about
too million properties. Look at the last that's indeed data
(04:01):
and usually on two million private dwellings. If you look
at sort of the last screw maybe the last twenty
years of buildings that have got double glazing and you know,
some form of insulation that leaves a huge amount you
know that that are going to be single glazed problems,
missing insulation walls, and it's of the scale that the
building you know, the industry can't build its way on
that problem. We can't replace those buildings. The capacitive you know,
(04:24):
industry running at full capacity would take decades to get
through that level of work. So it would have to
be a retrofit kind of scenario to to really improve
some of these older stocks, and of.
Speaker 2 (04:35):
Course some of that retrofit work is quite extensive, you know,
Like arguably, you could go, hey, look, if i've got
single glazing, it's kind of low hanging fruit. Right in
most cases, probably ninety five percent of cases, it's it's
a relatively straight forward process to go, I'm going to
take that single glazing out. I'm going to retrofit some
double glazing into that space. But once we reach walls
(04:58):
and hard to reach underfloor areas and so on, it
becomes a little bit more challenging. So the lack of
insulation is that in and of itself a reason that
we have so much mold in our houses.
Speaker 3 (05:10):
Yeah, that's one of the major contributors. And also ventilation
as well as a big one. Yep. So I mean,
if you look at what happens on the inside surface
of a building, that's really controlled by the way people
are living and what those surface seperatures are. And so
that's that's down to your heating and ventilation and your
level of insulation, and that doesn't get into the space
(05:31):
where what's happening inside the building cavities as well, So
what's happening inside roof spaces for example, where we're seeing
increased reporting of moisture and roofs yep in recent in
recent years. So yeah, the insulation is a big part
of it, but we also need to be mindful that
we really have to ventilate well. You know, as a nation,
we've never really done it that well. We've just kind
(05:52):
of got away with it with buildings that are relatively leaky. Yes,
but now we're at the point where you know, we're
building a little bit more air tight, which is great
for keeping heating, but it's really exposing that we're not
ventilating properly, and it's it's something that we're trying to
address at the moment.
Speaker 2 (06:07):
And so our code requirements around ventilation is it's a
bit out a date to be blunt.
Speaker 1 (06:16):
That's that would be my.
Speaker 3 (06:17):
Opinion of it. Yeah, yeah, five percent the floor area
if I open the windows, basically as your typical compliance
pathway for domestic drillings, and we seriously need some compliance
pathways for say mechanical ventilation that allows the industry to
actually grow. You know, it's establish a good set of
rules around it, make sure it gets done well. But
(06:38):
that's that's you know, the sort of thing that's definitely
happened overseas and it makes a big difference to health productivity,
all those things.
Speaker 2 (06:47):
Can I start with, I don't know, we've already been chatting,
but just a question what is mold like? If you
have to say what not so much how does it
get there? But what actually is it? If I go
in and I, you know, go to the back of
the wardrobe and I find that there's a blackish patch
on the plaster board, what actually is it?
Speaker 3 (07:07):
It's a it's a living organism, it's a it's a fungus.
It's yeah, it's and it's not actually the presence of
it on the wall that's really the big issue for people.
It's it's it's what comes off and gets into the air.
It's the spores that get into the air and those
kinds of things that are really the thing that that
has a health impact.
Speaker 2 (07:26):
Right, So people when they talk about mold, will will
talk about you know, stacky botros So is that a
particular type of mold and is that particularly hazardous to
human health?
Speaker 3 (07:39):
Yeah, that that's probably one of the worst ones we've
got around, and that was prevalent in a lot of
the leaky buildings where you have a large amount of
water that was accumulating inside walls that that can be
quite toxic.
Speaker 2 (07:50):
Yes, and how is it that that develops? And you know, like,
how do you like, do you get a good mold?
Probably not, but you get one that's not inurious.
Speaker 3 (08:00):
To pensylm was derived from from molds. You know there
are there are good mold out there, but yeah. It's
the funny thing is people say, you know, associated only
with with condensation, and that's one thing to be to
be wary of. So mold will actually grow when the
relative humility gets above about eighty percent. So it's it's
(08:22):
one of these things that if it stays wet enough
for long enough on a surface or damp enough, it
doesn't have to be actually you know physical water drops there. Yes,
it can, it can, it can start to grow. If
it gets too cold, it will slow down. So that's
really really cold spaces will not tend to grow it.
(08:42):
And it's you know, if you look at the sort
of there's a few technical teams I won't check out there,
but when when you when you increase that relative unity
even more, that the rate of growth speeds up quite
a lot. Right. For example, if you were if it
was around eighty percent, you know, on a surface for
for a month, you'll you start to see some mold.
(09:02):
But if it was around ninety five percent, you see
for some species you'll see mold with it a few days.
Speaker 2 (09:07):
And look, I was at a presentation the other day
where they had sort of a twelve month serve a
relative humidity for Auckland, Wellington and christ Church. Auckland regularly
for an extended period of time was above ninety percent
relative humidity.
Speaker 3 (09:23):
Yep. And that's also the danger when you're when you're
looking at just look at relativity and without taking temperaure
into account. Right, So when you bring that outside air
at relativity into your house, you change the temperture of
it so that that actually changes the relative humidity. So
it's not as bad as saying that Auckland's always going
to be ninety five in the building, because the change
(09:45):
in temperature will change what that relative mumidity is. Yes,
But the thing is it is high enough in Auckland
that for I think it's it's thirty percent of the
year fortydred percent of the year that it is wetter
outside than you would like inside. If you're trying to
keep the rh between forty and sixty percent under a
normal temperature. Yep. Absolutely, it's it's a big problem for
(10:09):
Auckland especially, and are anywhere really north of about your
Plumbus and Hamilton. Yep. It becomes more and more of
an issue because you're at this place where you're relying
on dilution as your primary means of getting rid of
that moisture. But if the air that you're diluting it
with through outside has got plenty of moisture in it,
(10:30):
you're You're you're in a hidings nothing to actually get
rid of it.
Speaker 2 (10:32):
Sometimes it's a particular geographical challenge, isn't it for certain regions,
which I think we're only just starting to understand that.
It's it's like we're in an environment where it's because
you can't change the relative humidity outside, right, there's nothing
we can know about that. No, we're not changing the
climate in these areas, but we are going to have
(10:53):
to learn to deal with it. So I'm going to
take a short break. I'm going to come back, and
what I'd really like to do is go, okay, so
if you fifty percent of our houses have got visible
mold the size of an a four bit of paper.
What do we do as homeowners as tenants? You know,
what are the things that because I think some of this,
if we're really honest, is operate error, right, a lack
of awareness, and so we're not using our houses right
(11:17):
in order to control the.
Speaker 1 (11:18):
Mold news talk zibby with.
Speaker 2 (11:22):
Me this morning, doctor Steve McNeil from Brands or Dr
Mold to his mates. So we've got a house. We
know that. You know the surveys out there right, seven
hundred and fifty houses long term survey, fifty percent of
them reporting mold as occupants, whether we own it, whether
we rent it? What do we do? Like basic things
that we should all be doing.
Speaker 3 (11:44):
Basic things. You really need to make sure that you're
trying to control the moisture sources in the building. Yes,
you try and try and draw your clothes outside if
you can. If you can't, make sure we're using a
dryer that's been to to outside the other option, but
that obviously comes with the power cost yep uh. The
(12:07):
The other thing is, you know, really really basic stuff
like you know, using pots on on on on the stove,
all those using listing pots on the stove for example,
though those things are are dead simple and they can
they can seriously decrease the metamorshure that that you're pumping
out into the building. But also, you know, keeping on
top of ventilating the building properly as well is a
(12:28):
good thing. One thing that's that's that feels a bit counterintuitive,
but the whole practice of the German practice of what
they call shop ventilation, where you go around and you
just open up all the windows first thing in the
morning and then close them and do that kind of
thing every every few hours. If if you don't have
a ventilation system, that that's a perfectly adequate way to
help deal with with some of that load. You know,
(12:51):
we can't have we can't have everyone, you know, living
in a perfect house. You have to deal with what
you have, Yes, exactly. I think that that that's quite
a practical step. And a really important thing for that
is when you when you open your windows stuff to
flush that that moisture out. Don't be afraid to do
that when the air is warm. Right, it sounds really counterintuitive,
(13:12):
but within you as long as it's only open for
a few minutes, yep. By the time you close the
windows again, but the heat has not left all of
the materials in the building, and that holds a lot
more heat than what the air was holding that you
just let out. If you're worried about comfort, just doing
a couple of minutes of everything wide open and closing
it again can actually be quite effective. So we resually
(13:35):
did a study in Wellington a few years ago with
a family in a pretty modern house that we're dealing
with connosation on the on the frames of their double
glaze one yes, and we measured some measured the conditions
and said, hey, look this is what it's like outside
if you just did this. And I think we went
from something like an eighty percent chance of finding real
(13:57):
to humidity of eighty percent to something like a forty
percent chance within a couple of weeks.
Speaker 2 (14:03):
And that literally is as simple as get up in
the morning. Maybe not at quarter past five when I
got up this morning, but get up in the morning,
you know, open the back door, open the front door,
open a couple of windows, let the air circulate through
the house for five minutes, ten minutes, close it up
again and then, like you say, the heat that's in
(14:24):
your walls and finish you're not losing that, you're just
using losing that moisture that's in the air.
Speaker 3 (14:31):
Yeah, I mean the heat capacity of all the materials
and you're building far exceeds what's in the air. You're
not doing it for too long, you know. I had
a study that we did a few years ago on
that ventation house that you came to visit, yes, where
we had one of the one of the new guys
was was was task was arriving every morning at exactly
eight o'clock and opening the windows conditioning conditioning in one
(14:52):
of the rooms to a particular temperature and humility. And yeah,
we learned some really interesting stuff from that, and it's
it is really that that short period and there's not
really much benefit of leaving it open for a long
long period after that, right unless your building get gets
warm from the sun. You know, you really need to
mobilize that moisture out of materials to get out of
(15:14):
the house. And so it can be an effective thing.
I mean, ideally year were to have everyone having you know,
hit recovery, mechanical ventilation, all that kind of stuff, but
you know that stuff that will take time for people
to eventually get The.
Speaker 2 (15:32):
Other day when I was talking with some of the team.
Speaker 3 (15:34):
There was.
Speaker 2 (15:37):
A simple two page advisory note that someone sent to
me from Brands Brand's Healthy Homes and it's basically about
temperature and humidity and so on. It's just a two pager.
It's really simple. It's bloody good information, to be fair.
I'm going to put a link up on my Facebook
page now or shortly if people want to read, you know,
(15:58):
if they want to go deep dive into this, this
information is available. How would you find the results for
the HEP two study.
Speaker 3 (16:06):
So that's all on the brand's website Brands dot dot
crodor In did and we are about to launch a
brand new one very soon, so within the next month.
I'm I'm sure it's within the next month. And so
that's going to make things a lot more easy to
find because it's that's always been a challenge with any website,
you know, you get more and more information, trying things
get gets more of a challenge. But there's been a
(16:26):
really good reorganization done. So that's that's about to go
go live very soon.
Speaker 2 (16:32):
Fantastic.
Speaker 3 (16:32):
So yeah, your your link, your link may change.
Speaker 2 (16:35):
Yeah, well I'll get this one out because it's a
really simple pdf. You know, print it off, put it
up at home and use it. Steve, thanks so much
for your time this morning. Actually, here's a quick text.
What if it's foggy, would you still open the house up? Yes,
you would.
Speaker 3 (16:51):
Yeah, if it's colder outside then it's inside. It's it's
gonna happless moisture in the air. Yep. The amount of
moisture in the air is very, very steeply dependent on
the temperature. Yes, so even if it's even by a
couple of get up.
Speaker 2 (17:05):
Open the doors and windows ten minutes, close them.
Speaker 1 (17:08):
Up, go for it.
Speaker 3 (17:10):
Like when it's when it's pouring down with the rain
and five degrees outside and you like, I don't want
to open the window. It's going to be one hundred
percent hourach outside. The thing is, though, that that year
that's only five degrees can can hold only a tiny
fraction of the moisture that right is in your building.
So it can still be quite effective at getting rid
of getting rid of moisture. Fantastic foggy and the same
(17:32):
temporature as your house. It's a different story.
Speaker 2 (17:34):
Okay, yeah, oh hey, look this is this has been fantastic.
We'll we'll get you back on and go take a
bit of a deep dive into this. But thanks and
thanks so much for joining us this morning.
Speaker 3 (17:45):
All right, thanks better.
Speaker 2 (17:46):
Been pleasure to take care Steve, your news talk s.
Let's get into the garden. Eight hundred and eighty ten
eighty four climb past. You can text as well nine
to nine two and I promise you before lunchtime today,
I'll put up this link for this pdf from Brands
on my Facebook page to just search for Resident Builder.
You can find the link for more from.
Speaker 1 (18:08):
The Resident Builder with Peter Wolfcamp. Listen live to Newstalk
ZB on Sunday mornings from six, or follow the podcast
on iHeartRadio
Popular Podcasts
Joy 101 with Hoda Kotb
Joy is essential. And it's also elusive. You can't order it, borrow it, or simply hope it into life. But now, there's a new and exciting way to start your journey toward a more joyful existence: The Joy 101 Podcast with Hoda! Best known for her Emmy-winning work and co-anchoring Today, Hoda Kotb infuses her authenticity, curiosity, and warmth into conversations with the world’s most fascinating people. Entertainment legends, sport icons, wellness experts, and everyday folks will share how they find, allow, and experience joy. Hoda will offer her own tips and takes on seeking a more balanced, harmonious life. If you're craving inspiration, support, and useful tools to maximize your joy, tune in to these candid, uplifting, and moving on-air chats. Joy after a breakup, joy as an empty-nester, joy after loss, joy as a caretaker — Hoda's new podcast will speak to you. Joy 101 with Hoda Kotb, an iHeartPodcast.
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.
Dateline NBC
Current and classic episodes, featuring compelling true-crime mysteries, powerful documentaries and in-depth investigations. Follow now to get the latest episodes of Dateline NBC completely free, or subscribe to Dateline Premium for ad-free listening and exclusive bonus content: DatelinePremium.com