Asbestos soffits
Michael Lakeman
needs to seal and re-paint them.
What is the best paint for the job?
Thanks.
Keith Mendum
A smooth masonry paint, preceded by a surface sealer?
You may well find that your (on site?) asbestos inspectors can offer
some practical advice as well.
--
Keith Mendum
My opinions, not Shell's
Check addresses before emailing.
Matt the Rat
>A colleague has asbestos soffits which have badly flaking paintwork. He
>needs to seal and re-paint them.
>What is the best paint for the job?
So how do you tell they are asbestos?
A couple of weeks ago I cut a hole in mine a for an extractor fine. I was a
bit surprised to find it wasn't wood as it never occured to me that they
might be made of anything else. It was a bit like a thick hard plasterboard.
This particular bit of the house was built in the early 70s If it was
asbestos anybody know what it might be.
--
Matt the Rat
Reply to matt DOT helliwell AT net DOT ntl DOT com
Mark Roberts
<s...@sig.nospam> writes
>Michael Lakeman wrote in message <370B7176...@madley.bt.co.uk>...
>>A colleague has asbestos soffits which have badly flaking paintwork. He
>>needs to seal and re-paint them.
>>What is the best paint for the job?
>
>So how do you tell they are asbestos?
>
>A couple of weeks ago I cut a hole in mine a for an extractor fine. I was a
>bit surprised to find it wasn't wood as it never occured to me that they
>might be made of anything else. It was a bit like a thick hard plasterboard.
>
>This particular bit of the house was built in the early 70s If it was
>asbestos anybody know what it might be.
:(
most likely was asbestos
when I was a kid I used to hold the boards down while my dad cut soffits
out of them with a circular saw .........in the seventy's .........
:(
--
Mark
Andrew May
Matt the Rat wrote in message <7eltsu$run$3...@nclient5-gui.server.ntli.net>...
>Michael Lakeman wrote in message <370B7176...@madley.bt.co.uk>...
>>A colleague has asbestos soffits which have badly flaking paintwork. He
>>needs to seal and re-paint them.
>>What is the best paint for the job?
>
>So how do you tell they are asbestos?
>
>A couple of weeks ago I cut a hole in mine a for an extractor fine. I was a
>bit surprised to find it wasn't wood as it never occured to me that they
>might be made of anything else. It was a bit like a thick hard
plasterboard.
>
>This particular bit of the house was built in the early 70s If it was
>asbestos anybody know what it might be.
>
Dunno about the 70's but when I had mine replaced a couple of years ago they
used something called Masterboard. A lot softer than asbestos, a lot lighter
and waterproof.
Before I get flamed for not doing it myself it was done as part of a general
re-roofing exercise at the request of the mortgage lender.
Was also recommended to me for bridging the cavity for a new window cill
when I made the kitchen window bigger.
Andrew May
Cambridge
Keith Mendum
>
> Michael Lakeman wrote in message <370B7176...@madley.bt.co.uk>...
> >A colleague has asbestos soffits which have badly flaking paintwork. He
> >needs to seal and re-paint them.
> >What is the best paint for the job?
>
> So how do you tell they are asbestos?
>
> A couple of weeks ago I cut a hole in mine a for an extractor fine. I was a
> bit surprised to find it wasn't wood as it never occured to me that they
> might be made of anything else. It was a bit like a thick hard plasterboard.
>
> This particular bit of the house was built in the early 70s If it was
> asbestos anybody know what it might be.
The type of board used in this application is usually fibre reinforced
cement. A small percentage of the fibre is the less unsafe type of
asbestos (less unsafe because it is long fibre). Short of grinding it
and inhaling the dust, the risk from cutting this stuff is limited and
the cement probably does more harm than the asbestos. If cut damp, the
risks are reduced further.
Asbestos board is rarely found in external applications, as the stuff is
far from water resistant and a fire resistant board is way over the top
when all that is needed is to close a gap, keep out the weather and
rodents etc.
By the 70s, the dangers of asbestos fibres were known and usage was
being restricted (slowly). Cement boarding manufacturers found that
there were satisfactory alternatives to asbestos, which were quite
possibly cheaper and easier to handle.
(This is bought to you by someone who spent some years paying to have
the stuff identified and encapsulated/removed by appropriately qualified
contractors whilst trying to get on and provide LANs round buildings)
--
Keith Mendum
My opinions, not Shell's
Check addresses before emailing me.
Matt the Rat
>Matt the Rat wrote:
>> This particular bit of the house was built in the early 70s If it was
>> asbestos anybody know what it might be.
>
>The type of board used in this application is usually fibre reinforced
>cement. A small percentage of the fibre is the less unsafe type of
>asbestos (less unsafe because it is long fibre). Short of grinding it
>and inhaling the dust, the risk from cutting this stuff is limited and
>the cement probably does more harm than the asbestos. If cut damp, the
>risks are reduced further.
>
>Asbestos board is rarely found in external applications, as the stuff is
>far from water resistant and a fire resistant board is way over the top
>when all that is needed is to close a gap, keep out the weather and
>rodents etc.
<snip>
Well that's all very reassuring.
I think I've decided it may (or may not) be asbestos. As I don't currently
need to cut any holes in it and somewhere else somebody mentioned that it
can be safely painted (just don't rub down), it looks like I'll be best of
leaving it well alone.
Holly
>>
>> A couple of weeks ago I cut a hole in mine a for an extractor fine. I was
a
>> bit surprised to find it wasn't wood as it never occured to me that they
>> might be made of anything else. It was a bit like a thick hard
plasterboard.
>>
>> asbestos anybody know what it might be.
>
>The type of board used in this application is usually fibre reinforced
>cement. A small percentage of the fibre is the less unsafe type of
>asbestos (less unsafe because it is long fibre).
I know Matt has now solved his particular problem, but a number of people
have mailed me for more information about this so I think it is worth
replying anyway. Apologies to Nick Maclaren for not replying more fully to
his post in the fire bricks thread. I should also add that I no longer work
in this area so this is a personal opinion only. The Environmental Health
Depts of Local Authorities will offer specific, up to date advice and
possibly sampling and testing facilities. If anyone thinks they may have a
problem with asbestos, this would be the best place to ask. In general,
asbestos boards etc will not pose a problem unless worked on. Storage
heaters may release fibres if banged etc (don't kick them if they go wrong
:-) ) or if dismantled.
This type of asbestos cement board usually contains white asbestos. The
bundles of fibres you can see in the board break down into microscopic
fibres just as those of brown and blue asbestos do. It is these tiny fibres
that pose the health risk. Blue asbestos has been found to be more
dangerous than brown asbestos which again is worse than white asbestos, and
the occupational exposure limits are set to take account of these
differences. But white asbestos is thought to cause both asbestosis (but a
large dose over a long period of time is involved) and, more importantly in
this case, mesothelioma, which is an incurable cancer of the membrane around
the lungs. Now the risk in this case would be very small (the people with
asbestosis have lungs clogged with asbestos and still have not contracted
mesothelioma) but nevertheless it is there and having worked in this field I
personally would not want to take it.
Short of grinding it and inhaling the dust, the risk from cutting this stuff
is limited and
>the cement probably does more harm than the asbestos. If cut damp, the
>risks are reduced further.
Quite substantial numbers of fibres are produced by cutting or drilling this
type of product. If it is necessary to work on a board, if possible it
should be removed whole and replaced with a new board, cut to size. If it
*must* be cut, hand tools only should be used, and damping it down would
indeed help.
>Asbestos board is rarely found in external applications, as the stuff is
>far from water resistant and a fire resistant board is way over the top
>when all that is needed is to close a gap, keep out the weather and
>rodents etc.
>
>By the 70s, the dangers of asbestos fibres were known and usage was
>being restricted (slowly). Cement boarding manufacturers found that
>there were satisfactory alternatives to asbestos, which were quite
>possibly cheaper and easier to handle.
The use of most asbestos products had been restricted by then, but asbestos
cement continued to be used, most commonly as corrugated roofing. It
wouldn't be uncommon to find asbestos cement soffits in houses built in the
early 70s.
I think Nick was right in saying that there are possibly other substances
around that are likely to pose more of a health risk during the normal
course of our lives. But since asbestos is known to be a risk, it is wise to
minimise one's exposure as much as possible.
>(This is bought to you by someone who spent some years paying to have
>the stuff identified and encapsulated/removed by appropriately qualified
>contractors whilst trying to get on and provide LANs round buildings)
>
This is brought to you by someone who has sampled more asbestos, carried out
more air tests, supervised more asbestos removal contracts (and quite
possibly breathed in more asbestos fibres) than she cares to remember!...:-)
Sorry it became so long!
Holly
ho...@esatclear.ie
Thomas Prufer
<ho...@NOSPAM.esatclear.ie> wrote:
>Quite substantial numbers of fibres are produced by cutting or drilling this
>type of product. If it is necessary to work on a board, if possible it
>should be removed whole and replaced with a new board, cut to size. If it
>*must* be cut, hand tools only should be used, and damping it down would
>indeed help.
>
(...)
>The use of most asbestos products had been restricted by then, but asbestos
>cement continued to be used, most commonly as corrugated roofing. It
>wouldn't be uncommon to find asbestos cement soffits in houses built in the
>early 70s.
There are some points I'd like to add. I came across these when trying
to figure out what to do with a corrugated asbestos roof on a shed.
Breaking asbestos cement and cutting it with a power grinder will also
release dust in nasty sizes. This would also apply to asbestos board.
Also wire-brushing or pressure-washing asbestos roofing - as one might
to get the moss etc. off preparatory to painting - is not good.
Weathering is not a major problem in roofing, as any fibers released
will be long, and not the fine dust that causes the problems asbestos
is known for. (As this bit of information is from an asbestos roofing
ex-manufacturer, it may be a bit optimistic).
Bituminous roofing paint is a cheap sealant that will keep the fibers
from being released. The cheap kind I used looks like it will need
annual repainting; better kinds may last longer. There are special
roof paints (in several colors) that will last at least five years, as
a paint salesman assured me. They are not suited if there are remains
of bituminous paint on the roof, though.
Baby oil will remove bituminous paint from skin nicely, and is less
smelly than diesel oil or kerosene. There are ready-packed oil wipes
which clean this (and other paints) very well, as they are quite
amazingly rough given their intended purpose on babies' bums.
I have removed small pieces of asbestos board, and have found "tack
rags" very useful in getting the dust up. These are large, thin, cheap
pieces of cloth coated in some sort of sticky gum. The gum doesn't rub
off when the cloth is wiped over something. They are used in picking
up even the finest dust before painting automobile bodywork and such.
Tack rags pick up more of the finest dust than a vaccuum cleaner will,
and are disposable.
Thomas Prufer
Big Egg
pru...@compuserve.com (Thomas Prufer) wrote:
> On Wed, 14 Apr 1999 23:14:53 +0100, "Holly"
> <ho...@NOSPAM.esatclear.ie> wrote:
> >The use of most asbestos products had been restricted by then, but asbestos
> >cement continued to be used, most commonly as corrugated roofing. It
> >wouldn't be uncommon to find asbestos cement soffits in houses built in the
> >early 70s.
>
> Bituminous roofing paint is a cheap sealant that will keep the fibers
> from being released. The cheap kind I used looks like it will need
> annual repainting; better kinds may last longer. There are special
> roof paints (in several colors) that will last at least five years, as
> a paint salesman assured me. They are not suited if there are remains
> of bituminous paint on the roof, though.
As an aside, does anyone have a recommendation as to how to waterproof
a corrugated asbestos garage roof?
The roof leaks through old fixing holes, and by water running back under
the upper sheet where it overlaps the lower:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<---WATER<-------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I was thinking of either a bitumous coating over the entire roof, or
laying a thin layer of concrete (10mm?) over it. (Presumably with some
sort of expansion joints at suitable intervals).
The roof is about 12'x20',flat (without a ridge), with a drop of about
1ft down the from front to back. Replacing it completely is not really
an option.
--
Big Egg
Any unsolicited e-mail is subject to a 500US$ download and archiving charge at my discretion. E-mailing the above address is deemed to be acceptance of this contract.
Keith Mendum
>
[snip]
> As an aside, does anyone have a recommendation as to how to waterproof
> a corrugated asbestos garage roof?
>
> The roof leaks through old fixing holes, and by water running back under
> the upper sheet where it overlaps the lower:
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> <---WATER<-------
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> I was thinking of either a bitumous coating over the entire roof, or
> laying a thin layer of concrete (10mm?) over it. (Presumably with some
> sort of expansion joints at suitable intervals).
> The roof is about 12'x20',flat (without a ridge), with a drop of about
> 1ft down the from front to back. Replacing it completely is not really
> an option.
The bitumous coating sounds a good idea, would the colourless silicone
fluid be any good as an alternative? The weight of an additional layer
of concrete will almost certainly cause the roof to collapse - the stuff
is heavy! If the roof only leaks thru the holes and at the overlaps, I'd
fix those problems first, with a sealant from a cartridge.
Andrew Dunkerton
d...@nospam.ope.shell.com> writes
>Big Egg wrote:
>>
>[snip]
>> As an aside, does anyone have a recommendation as to how to waterproof
>> a corrugated asbestos garage roof?
>>
>> The roof leaks through old fixing holes, and by water running back under
>> the upper sheet where it overlaps the lower:
>>
>The weight of an additional layer
>of concrete will almost certainly cause the roof to collapse - the stuff
>is heavy! If the roof only leaks thru the holes and at the overlaps, I'd
>fix those problems first, with a sealant from a cartridge.
TAKE CARE !. Asbestos sheeting goes very brittle with age and the weight of an
adult is too much for it to bear. I come from a farming background and I know of
many instances where people have fallen through aforesaid sheeting, and some
have been killed. Make sure you get some scaffolding boards (or similar) to spread
your weight across the rafters and not on the sheeting itself. Even a fall through a
single story roof is likely to be crippling, since it happens so quickly you haven't got
time to brace yourself before you land on what ever is below, like an upturned
garden rake or some other nasty sharp object. Just hitting the concrete awkwardly
is enough to break ankles/legs/pelvises and if you topple though and hit the deck
head-first - it may be 'Good-by sweet world'. Maybe this newsgroup should have
a compulsory warning about safety before anyone can subscribe to it.
If water is seeping back up through an overlap then either the overlap is too short
or the pitch of the roof too shallow, but it may just be because there is an
accumulation of moss and/or silt which is acting like a wick. Try cleaning it first
with bleach or something. Don't powerjet it, since this may dislodge asbestos
fibres (see other posts).
The best sealer that I have used is Isoflex, but make sure you use the
recommended primer too. It's expensive and the primer needs a special solvent
to clean the brush; even petrol wouldn't shift it. To do the whole roof would
cost at least £100 if my experience is anything to go by, but you could do it more
cheaply by just doing the joints. It cures to form a flexible rubber layer and doesn't
seem to shrivel up and crack under the influence of the sun in the way that other
diy roofing 'repair' materials seem to. There is also some silver/white 'paint' that
can be applied to reflect the heat of the sun which would make it last even longer.
PS are the old fixing holes in the valleys or on the ridges ?. The whole point of
fixing any corrugated sheeting material without leaks is to drive the fastenings
through the ridge. Someone should point this out to the contractor who is
refurbishing many railway stations in (what was) Southern Region, or better still
point out the error of their ways to Railtrack.
A.D.
Nigel Orr
<and...@skydata.demon.co.uk> wrote:
>PS are the old fixing holes in the valleys or on the ridges ?. The whole point of
>fixing any corrugated sheeting material without leaks is to drive the fastenings
>through the ridge. Someone should point this out to the contractor who is
>refurbishing many railway stations in (what was) Southern Region, or better still
>point out the error of their ways to Railtrack.
Do you put a spacer of some kind between the ridge and the purlin that
it is being fixed to? If not, how do you stop the ridge being crushed
as you tighten the fixing?
Nigel
Keith Mendum
>
> Do you put a spacer of some kind between the ridge and the purlin that
> it is being fixed to? If not, how do you stop the ridge being crushed
> as you tighten the fixing?
>
Cement sheeting is very rigid and you will deform the fixing (assuming
you are using one of the correct types) before you break the sheet - you
only need enough tension in the fixing to ensure a weather-tight seal.
Plastic sheeting does require some sort of spacer, as do some types of
metal sheet.
Matthew Marks
Andrew Dunkerton <and...@skydata.demon.co.uk> writes:
> Maybe this newsgroup should have
> a compulsory warning about safety before anyone can subscribe to it.
Have you read the FAQ?
Your comment could apply to a great many newsgroups, and unfortunately there
is no accounting for stupidity.
--
Matthew @rd.bbc.co.uk My opinions, not Auntie's
For the uk.d-i-y FAQ, goto http://www.mdx.ac.uk/~john49/faq0.htm