[OT] Flat roof area - for insurance purposes

[Tim Watts]

It's not *exactly* a legal question but I wondered if there was an
industry standard for how to measure the relative areas of a roof
comprised of different fabrics?

The question that always comes up when I do my insurance quotes is: do
you have a flat roof and if so what percentage of the roof is flat?

Well:

1) I assume this is plan-projection area (ie horizontal area), not
actual surface area? For a nearly level flat roof of course the areas
are nearly the same - but the main hipped roof plan-projection is rather
less than the materials surface area.

2) Is it conventional to include bay windows with flat elements that
project outside the main rectangle of the house - or just the major
areas such as a dormer flat roof?

The reason to ask is mine is marginal - right on the boundary on a
threshold that makes a difference to conditions and premiums. Marginal
enough to make it worth taking a tape measure to the whole thing and
being sure of what is being measured.

The insurers never seem to know the answer when I have asked them the above.

So I just wondered if anyone knew of an industry standard?

Ta

Tim

[steve robinson]

On Thu, 13 Aug 2015 13:38:26 +0100, Tim Watts <tw_u...@dionic.net>
wrote:

Yes you should include your bay roof , The area of your tiled roof is
ridge to eaves from wall to wall or hip to hip , its not the footprint
of your house which is likely to be considerably smaller.

I usually quote flat roof xxx sq meters
Tiled roof xx square meters , you have then clarified tile coverage
not footprint work out the percentages and away yuo go

[newshound]

Can't really help, but it would never really have occurred to me to
regard the bit on top of a bay as "flat roof", even though it is, strictly.

I would certainly go with working on plan areas, the point is not so
much the physical area of roof as the *volume* of building contained in
the two parts.

[Tim Watts]

On 13/08/15 14:38, steve robinson wrote:

> Yes you should include your bay roof , The area of your tiled roof is
> ridge to eaves from wall to wall or hip to hip , its not the footprint
> of your house which is likely to be considerably smaller.
>
> I usually quote flat roof xxx sq meters
> Tiled roof xx square meters , you have then clarified tile coverage
> not footprint work out the percentages and away yuo go
>

OK - thank you Steve.

[David]

I assume you have tested the water with other insurers?

NFU seem remarkably relaxed about the flat roof on our property.


Cheers


Dave R

--
Windows 8.1 on PCSpecialist box

[Tim Watts]

On 13/08/15 15:37, David wrote:

> I assume you have tested the water with other insurers?

Previously, others have not been too bothered.

But I need the current insurer for the moment for other reasons - and
they are surprisingly thorough - plus I was making sure this time around
that all the i's were dotted and t's crossed.

[Ian Smith]

On Thu, 13 Aug 2015 14:38:09 +0100, steve robinson <st...@colevalleyinteriors.co.uk> wrote:
>
> Yes you should include your bay roof , The area of your tiled roof is
> ridge to eaves from wall to wall or hip to hip , its not the footprint
> of your house which is likely to be considerably smaller.

What is your basis for this advice? It's not what I do, and not the
other advice in the thread.

That is, I quote the plan projection area (which is less than the roof
surface area). I give them the total roof plan and the area that's
flat.

regards, Ian SMith
--
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[steve robinson]

They are asking for the roof area not the footprint of the building ,
a bay roof by definition is a roof , often flat, sometimes tiled.

I base my advise on nearly 40 years in the building industry , using
the standard forms of measurement used over that time within the
industry

It will be the same standard forms of measurement insurance companies
may reference to .

Tiled roofs are not the problem, insurance companies don't like large
flat roofs, they have a habit of springing leaks and consequential
damage can be substantial, also provide easy access to upper floor
windows which are generally less secure on older properties and more
likely to be left onlocked or on vent.
My favourite method of entry in years gone by (legally off course)

[Tim Watts]

On 14/08/15 10:39, steve robinson wrote:

> They are asking for the roof area not the footprint of the building ,

Just to clarify - you mean the area if you took each plane of the roof
and laid it down and measured it - ie NOT a plan projection of each
plane onto the ground (which itself is bigger than the footprint of the
building due to eaves overhang?

[steve robinson]

On Fri, 14 Aug 2015 12:08:31 +0100, Tim Watts <tw_u...@dionic.net>
wrote:

Correct , its easy enough to do

you need the height of the roof usually from a measurement in the
loft space and the depth and width of the building

square the height , divide the building depth by 2 then square it add
both measurements together square root that gives you the length of
the plane of the roof excluding eave detail

add 0.3 to the length of the plane (one eave) , add 0.6 to the width (
two eaves) multiply them together , multiply that figure by 2 and it
gives you the approx area of a detached roof with hips , you don't
need to calculate the area of the hipped ends because you have
accounted for that within the rectangular measurement ( the triangle
you would deduct from each rectangle either end matches the size of
the end hip) , ok for rule of thumb , usually pretty accurate to .

I could order tiles using this method and I was rarely far out

takes longer to explain than perform the maths (about 2 minutes )

[Tim Watts]

Thanks :)