On 23/04/2019 12:47, tony sayer wrote:
In article ,
scribeth thus
On Monday, 22 April 2019 20:10:25 UTC+1, Bill wrote:
In message , tony sayer
writes

However now that the damage has been done thin "ish" section Steel cold
dipped galvanised roof trusses and a coated ally roof materials .

Surely you mean hot dipped galvanised?

Painted to protect it from acid and sulphides in rain, that should last
for ever.
Not totally sure about coated ally, having had two Land Rovers.

'Well we tried to cold dip it, but encountered some resistance'

Galv is good but no hope of it lasting a century, let alone several.


NT

Dunno re that, was looking at some steelwork been in use 70 years looked
mint the steel underneath. They might have better coatings these days
anyway!...

galv will last as long as the zinc takes to get used up.

And thats is a function of how exposed the steel underneath is.


And the water/air exposure

--
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battle dance and dream of glory €¦ The good of dead warriors, Mother, is
that they are dead.
Sheri S Tepper: The Awakeners.