My son's 50 year old house has a detached garage with a roof made of
sheets of overlapping corrugated mineral material (asbestos-like),
sloping up from either side of the garage, and capped along its top by
overlapping /\ shaped pieces of the same material.
The roof is well supported inside the garage by means of a criss-cross
structure made up of angle steel.

When it rains the garage roof leaks in some places - not a lot, but
enough to wet anything stored in the wrong place below. When I went
inside the garage and looked up I could see the sky through quite a few
gaps where the /\-shaped capping pieces were supposed to be covering the
two sloping side-pieces. The outside of the roof is covered by quite a
lot of moss, much of it around the capping pieces so I'm wondering if
its growth may be responsible for some of the problem.

I would like to ask three questions :

1. What is the most cost-effective way and best material to seal the
gaps in order to deal with the water-ingress problem?

2. Are the roof sheets really likely to be a dangerous type of asbestos
and, if so, what additional care should be taken handling/repairing it?

3. What is the best, and safest, way of actually getting onto the roof
in order to clear the moss and actually effect the repairs?

Many TIA - Dave .

--
David C.Chapman - )
--------------------------------------------------------------------------

I had a similar problem with a moss-covered corrugated cement/fibre
roof. Removing the moss cured it completely.

It seems that the moss was damming the water at the overlaps, causing it
to rise under the overlapping sheet until it reached the top of the
underlying sheet.

The roof in question was around 10 metres by 5 metres so removing the
moss was tricky. I finally did it using a set of drain rods with the
spiral bit first to loosen the moss then the disc bit to drag it off the
roof. I taped a weight to the end of the rod to give it more purchase.

Stretching a couple of bare copper wires over the roof just below the
ridge is supposed to prevent the moss regrowing, but it's too early to
say whether this has worked yet.

HTH,

Roger.

On Sep 19, 3:01*pm, David Chapman wrote:

1. *What is the most cost-effective way and best material to seal the
gaps in order to deal with the water-ingress problem?

2. *Are the roof sheets really likely to be a dangerous type of asbestos
and, if so, what additional care should be taken handling/repairing it?

3. *What is the best, and safest, way of actually getting onto the roof
in order to clear the moss and actually effect the repairs?

I had something similar with a garage flat roof a few years ago. It
was covered in moss etc and letting water through in many places.

I used a short scaffold board on the roof to let me safely walk on it
and used a stiff yard broom and a hose to clean the surfaces. Once it
was clean and I could see it more clearly I replaced a few of the
fasteners that had become badly corroded or loose and then applied a
couple of coats of a bitumastic emulsion called"Ruffabrush". I bought
a 25 litre tub very cheaply from a roofing supplier.

I had only planned it to be a short term fix - but just checking
google - that was 7 odd years ago and it's still keeping the rain out.

--
Nige Danton

On Fri, 19 Sep 2008 09:01:58 +0100, David Chapman wrote:

1. What is the most cost-effective way and best material to seal the
gaps in order to deal with the water-ingress problem?

At 50 years old asbestos cement panels are probably pretty much at the end
of their life. I'd look to replacing them, maybe with a few
translucent/parent ones to let in more light. What condition are the
supporting angle irons, they might need looking at and maintaining if not
replacing as well.

2. Are the roof sheets really likely to be a dangerous type of asbestos
and, if so, what additional care should be taken handling/repairing it?

In this day and age *any* asbestos is considered dangerous. Hopefully you
won't have to go to expense of total negative pressure enclosure of the
entire structure for the removal of it but I wouldn't like to bet on it.
It'll still have to be double bagged and disposed of properly though. Have
a dig about on the web and see what you can find out before contacting an
asbestos removal contractor (so you can spot any bull****).

3. What is the best, and safest, way of actually getting onto the roof
in order to clear the moss and actually effect the repairs?

Very carefully on boards, the panels are likely to be very fragile.

--
Cheers
Dave.

"David Chapman" wrote in message
...

My son's 50 year old house has a detached garage with a roof made of
sheets of overlapping corrugated mineral material (asbestos-like), sloping
up from either side of the garage, and capped along its top by overlapping
/\ shaped pieces of the same material.
The roof is well supported inside the garage by means of a criss-cross
structure made up of angle steel.

When it rains the garage roof leaks in some places - not a lot, but
enough to wet anything stored in the wrong place below. When I went inside
the garage and looked up I could see the sky through quite a few gaps
where the /\-shaped capping pieces were supposed to be covering the two
sloping side-pieces. The outside of the roof is covered by quite a lot of
moss, much of it around the capping pieces so I'm wondering if its growth
may be responsible for some of the problem.

I would like to ask three questions :

1. What is the most cost-effective way and best material to seal the gaps
in order to deal with the water-ingress problem?

2. Are the roof sheets really likely to be a dangerous type of asbestos
and, if so, what additional care should be taken handling/repairing it?

Asbestos is only dangerous is disturbed (i.e.
grinding/drilling/cutting/breaking/etc). If you are careful when handling
then you should be fine.

On Sep 19, 9:01*am, David Chapman wrote:
* *My son's 50 year old house has a detached garage with a roof made of
sheets of overlapping corrugated mineral material (asbestos-like),
sloping up from either side of the garage, and capped along its top by
overlapping /\ shaped pieces of the same material.
* *The roof is well supported inside the garage by means of a criss-cross
structure made up of angle steel.

* *When it rains the garage roof leaks in some places - not a lot, but
enough to wet anything stored in the wrong place below. When I went
inside the garage and looked up I could see the sky through quite a few
gaps where the /\-shaped capping pieces were supposed to be covering the
two sloping side-pieces. *The outside of the roof is covered by quite a
lot of moss, much of it around the capping pieces so I'm wondering if
its growth may be responsible for some of the problem.

* *I would like to ask three questions :

1. *What is the most cost-effective way and best material to seal the
gaps in order to deal with the water-ingress problem?

really depends on the nature of the damage. I'd de-moss it and
reassess first, then tell us exactly whats amiss if it still drips.

2. *Are the roof sheets really likely to be a dangerous type of asbestos

yes and no. At 50 yrs old they'll be white asbestos. The safety of
free white asbestos is a matter of debate, however in your case its
locked into cement sheets so not a serious issue. However there is a
whole overpriced disposal industry that would love you to believe
those sheets will kill you and your descendants for the next 1000
years, and that you must pay them 4 figures just to bin the sheets for
you.

and, if so, what additional care should be taken handling/repairing it?

double bag it before disposal, and take to a tip that accepts
asbestos. They will simply bury it. Break it if necessary but best not
to saw/grind it.

3. *What is the best, and safest, way of actually getting onto the roof
in order to clear the moss and actually effect the repairs?

Old asbestos roofs are considered fragile, so large loadspreading
boards.


NT