[wendyg]

I have an outbuilding consisting of 2 sheds and toilet, they are covered with corrugated asbestos cement sheets which have started to leak.   There are no obvious large cracks, so I assume they must quite small, but there is water dripping through in all 3 buildings when we have heavy rain.  What is a cheap and easy (safe) way of waterproofing the roof?

Wendy

[arugula]

Short of replacing the sheets with metal corrugated, Siroflex make a number of good products. The polysulphide sealant or All Weather copolymer would make a repair for you. You could google for more info. or stockists.

[mike1987]

my first option would be to get rid of them if that isnt possible then there are a number of sealnts designed for asbestos http://www.kingfisheruk.com/item.php?id=55P
my stepdad was a asbestos stripper by trade and when i moved into a block of flats with quite a lot of drainpipes made from it he sprayed the with a 50:50 mix of pva glue and water
to seal in the fibres not sure if it is waterproof tho

[RichardA]

By all means take specialist advice on product from builders merchants BUT BUT BUT be aware that for any product to stick you will need to wire brush the asbestos cement clean of moss, muck, bird droppings etc thus releasing not only asbestos fibres but also a variety of moulds, spores and other biological materials with very serious health hazards. You and others will be affected and consequences incl health risks and complaints possibly also being sued for damages by neighbours could be considerable. I really do not think it is worth it. AC will continue to weaken and will need replacing eventually in any case. Sorry to be so negative -- I have been there and I did in fact paint my AC roof after cleaning under dripping wet conditions to reduce dust blow but I have considerable experience of asbestos. 2 years later I replaced the entire garage using specialist contrcators with appropriate licence and records of disposal.
R

[TerryB]

Get rid of it.
Asbestos is most dangerest the smaller the particle, when filed or 2 surfaces rub against each other.
Unlike other dusts just 1 very small spec traped in the lung can kill.

[fatcat1955]

Use black bitumen paint on both sides. Waterproofs and seals in the fibres.

[RichardA]

Sorry fat cat with respect you cannot paint without cleaning the surface and that releases hazardous materials incl asbestos fibres, please see my earlier posting. If you do it without cleaning the paint will fail. I have tried it and with my knowldge of asbestos I belived I cleaned thoroughly and safely and the paint worked but only for about 2 years. I have now replaced that roof.
Once AC fails especially by cracking along the corregations it should be removed with due precautions and replaced.
R