Over 10 years ago we built the Mother of All Sheds.

The roofing was corrugated steel sheet with a green plastic coating.

This last year the coating has started to lift off the areas which have
been in full sun.

I guess some remedial painting is required.
How long would the team expect the original coating to last?

Cheers

Dave R

--
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On 24/04/2022 15:18, David wrote:
> Over 10 years ago we built the Mother of All Sheds.
>
> The roofing was corrugated steel sheet with a green plastic coating.
>
> This last year the coating has started to lift off the areas which have
> been in full sun.
>
> I guess some remedial painting is required.
> How long would the team expect the original coating to last?

That will depend upon the environment. One manufacturer of such coatings
say their product should last between five and 200 years. The former in
areas with heavy industrial or marine contamination. The latter if used
underground.

--
Colin Bignell

On 24/04/2022 15:36, Colin Bignell wrote:
> On 24/04/2022 15:18, David wrote:
>> Over 10 years ago we built the Mother of All Sheds.
>>
>> The roofing was corrugated steel sheet with a green plastic coating.
>>
>> This last year the coating has started to lift off the areas which have
>> been in full sun.
>>
>> I guess some remedial painting is required.
>> How long would the team expect the original coating to last?
>
> That will depend upon the environment. One manufacturer of such coatings
> say their product should last between five and 200 years. The former in
> areas with heavy industrial or marine contamination. The latter if used
> underground.
>

200 years? Reminds me of Woody Allen:
https://www.youtube.com/watch?v=Xo2kSu6O8cU

On 24/04/2022 15:18, David wrote:
> Over 10 years ago we built the Mother of All Sheds.
>
> The roofing was corrugated steel sheet with a green plastic coating.
>
> This last year the coating has started to lift off the areas which have
> been in full sun.
>
> I guess some remedial painting is required.
> How long would the team expect the original coating to last?

About 5 years in full sun if you are lucky.

Hot tin roofs and plastic coatings are pretty well doomed to fail
quickly since the plastic expands much more than the metal and the whole
thing will get insanely hot in the sunshine for good measure.

Eventually the plastic will go brittle due to a combination of ozone and
UV damage then it will sheer off in flakes at the metal surface.

White plastic with a UV inhibitor should last the longest since it will
absorb less sunlight and still radiate thermally like a black body
keeping the roof a bit cooler will help.

There may soon be designer materials that stay cool in direct sunlight
and are cheap enough to use on roofs.

https://www.science.org/content/article/cheap-plastic-film-cools-whatever-it-touches-10-c

--
Regards,
Martin Brown

On 24/04/2022 16:03, Martin Brown wrote:

> Hot tin roofs and plastic coatings are pretty well doomed to fail
> quickly since the plastic expands much more than the metal

I was convinced it was the other way round, but you are absolutely
right. The coefficient of expansion of polythene (for example) is
roughly 10 times larger than that of steel.

David formulated the question :
> This last year the coating has started to lift off the areas which have
> been in full sun.

My garrage roof and workshop roofs, are steel, galv coated then some
sort of paint or plastic coat. The must be around 10 years old now and
absolutely no sign of any deterioration. Both are in full sun much of
the day. A local very large industrial building used the same material
for its walls, it was still in good condition 40 years after the build.

In message <t43pom$hhp$1@dont-email.me>, Harry Bloomfield Esq
<a@harrym1byt.plus.com> writes
>David formulated the question :
>> This last year the coating has started to lift off the areas which have
>> been in full sun.
>
>My garrage roof and workshop roofs, are steel, galv coated then some
>sort of paint or plastic coat. The must be around 10 years old now and
>absolutely no sign of any deterioration. Both are in full sun much of
>the day. A local very large industrial building used the same material
>for its walls, it was still in good condition 40 years after the build.

I have built/re-clad several farm buildings with AS35 box section
plastic coated steel sheet. So far (25 years) only one is peeling on the
sunny side. Steadmans, the manufacturer guarantees 20 years away from a
coastal environment.

--
Tim Lamb

On 24/04/2022 16:18, Harry Bloomfield Esq wrote:
> David formulated the question :
>> This last year the coating has started to lift off the areas which have
>> been in full sun.
>
> My garrage roof and workshop roofs, are steel, galv coated then some
> sort of paint or plastic coat. The must be around 10 years old now and
> absolutely no sign of any deterioration. Both are in full sun much of
> the day. A local very large industrial building used the same material
> for its walls, it was still in good condition 40 years after the build.

I was going to say the decent quality industrial stuff lasts decades. I
have some of the cheapest budget stuff available on a sort of lean-to
that was only going to be temporary, and that's lasted ten years.

On Sun, 24 Apr 2022 22:24:40 +0100, Tim Lamb wrote:

> In message <t43pom$hhp$1@dont-email.me>, Harry Bloomfield Esq
> <a@harrym1byt.plus.com> writes
>>David formulated the question :
>>> This last year the coating has started to lift off the areas which
>>> have been in full sun.
>>
>>My garrage roof and workshop roofs, are steel, galv coated then some
>>sort of paint or plastic coat. The must be around 10 years old now and
>>absolutely no sign of any deterioration. Both are in full sun much of
>>the day. A local very large industrial building used the same material
>>for its walls, it was still in good condition 40 years after the build.
>
> I have built/re-clad several farm buildings with AS35 box section
> plastic coated steel sheet. So far (25 years) only one is peeling on the
> sunny side. Steadmans, the manufacturer guarantees 20 years away from a
> coastal environment.

About a mile or so from the sea, me.

:-(

Dave R

--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64

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On Mon, 25 Apr 2022 22:24:19 +1000, newshound <sradcliffe544@gmail.com>
wrote:

> On 24/04/2022 16:18, Harry Bloomfield Esq wrote:
>> David formulated the question :
>>> This last year the coating has started to lift off the areas which have
>>> been in full sun.
>> My garrage roof and workshop roofs, are steel, galv coated then some
>> sort of paint or plastic coat. The must be around 10 years old now and
>> absolutely no sign of any deterioration. Both are in full sun much of
>> the day. A local very large industrial building used the same material
>> for its walls, it was still in good condition 40 years after the build.
>
> I was going to say the decent quality industrial stuff lasts decades. I
> have some of the cheapest budget stuff available on a sort of lean-to
> that was only going to be temporary, and that's lasted ten years.

We don't use plastic coated much at all. Painted properly works fine
and lasts far longer than 10 years. And has in fact almostly completely
replaced clay and concrete tiled roofs on new houses here now.

And with flat roofs you don't even need to paint, galvanised works
fine and mine has lasted more than 50 years now with no rust at all.