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N. Thornton
 
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Default Oversheeting Asbestos Roofs

Fwom:Autolycus )


While investigating the options for replacing the 35 sq metres of
asbestos cement roof that blew away in Saturday's gale, I have
discovered just how expensive asbestos disposal has become. One

local
firm has quoted £50 per sheet if I took it to them, or £850 for a

skip.
Derbyshire County council will only accept 2 square metres at a time

at
their sites.

I'm hoping the insurers (Zurich) will pay for the disposal of the
smashed sheets and the remainder of that roof which is now in a
precarious state, but I have another building of around 120 square
metres which is structurally sound but has a number of leaks in its
big-6 asbestos sheets as well as quite severe condensation problems

on
the underside of the roof. I don't relish removing the existing

sheets,
and I certainly don't relish paying for their disposal.

Does anyone have experience of "oversheeting" with steel, onduline,

or
other materials? I believe it can be done directly onto the sheets,
having first removed all the nails, or onto battens.



Maybe its time for the famous disposal trick? For those so desperately
poor as to be unable to afford a skip, building materials can be put
in domestic trash, a bit each week. Slowly it all goes away, free.
Just bag it in small bags rather than rubble bags, carrier bags ideal.

Asbestos should be double wrapped in plastic before being landfilled,
what the law says about putting it in the household trash I dont know,
cant tell you.

But I cant see this being much of an issue, since your insurer will be
liable for disposal anyway. Unless you decide to settle for cash and
dispose as cheaply as poss.


Re your 2nd building, I presume cement sheet, which is what asbestos
sheet is, could be cement lined to renovate it. Mixing fibres in for
reinforcemenr would make it behave musch like the asbestos there
already. Presumably one could make a good superstrong mix and trowel
it thinly onto the asbestos already there? Certainly be a big cost
saving.

Strong cement mix:
3:1 is ideal ratio for standar sand/cement only mix.
Add pva for increased adhesion
Add fibres for increased tensile strength and crack control
Add extra fine non-organic silt as well to improve granule packing,
thus increasing both comprssive and tensile strengths.

You could either treat the whole roof like this or just spot patch.


NT