Many thanks yet again for all of you that gave me advice/encouragement
during the build of my 50 square metre pyramid roof.
Its finished-and it does nt leak!!!.
After costs for zinc finish spiralled to an eye watering £250+VAT per square
metre I decided reluctantly to do it in glass fibre.
My Scottish supplier Allscot wwwallscotltd.co.uk
were a great help with practical advice I laid and finished the 50 square
metres in 4 days.
I would reccomend anyone with a flat roof to consider D-I-Y fibreglass-its
not cheap-but-it lasts and its waterproof.
Its a filthy job but very quick.
You need to be carefull to use the proper stuff tho roofing spec resin and
gel coat-it does not go brittle and the gel coat is fire retardent-a bit.
Just lay up a ply etc base- lay on roofing resin 1/2 to1 kilo per square
metre-lay down 600 gram chopped strand mat in 1 metre squares with 2 inch
overlap and overlay with resin rolled on top-aim for 11/2 to 2 kilos resin
per square metre.You should apply the gel coat right away 1/2 kilo per
square metre.
I would be quite happy to do a detailed description of my roof.
You can waste a lot of time tackling the job without the right stuff eg you
will need about 30 plastic tubs for 50 square metres Allscot price 80 pence
per tub Homebase £2.Dont waste time cleaning out plastic tubs at 80 pence
each-just use new ones.When you start you must not be deflected its not a
job to start and stop.
Use the proper resin rollers £2 each you need at least 3 a day-or a new one
every time you stop for 20 minutes-normal rollers are devoured by the resin.
Air temp must be above 7 degrees centigrade so its a job for a Scottish
summer.Rain is a no no not catastrophic just a major time waster since you
need all your tins pails hardener pots etc laid out-it takes some time.

Did you have to incorporate thermal expansion sections ? and what is the
colour of the gel coat?
Tom

Tom wrote:
Did you have to incorporate thermal expansion sections ? and what is the
colour of the gel coat?

Can be any colour you like, though it's probably wise not to choose
black - the roof will probably get a bit hotter than white.

Did you have to incorporate thermal expansion sections ?
No expansion sections although the pyramid is free to expand and contract as
it is raised on a 600mm high upstand the perimeter drain similarly can move
horizontally.

and what is the
colour of the gel coat?
Gel coat comes in standard grey which suited me as it matches zinc.
There is a bewildering choice of many shades-at least 30.

Can be any colour you like, though it's probably wise not to choose
black - the roof will probably get a bit hotter than white.

tom patton wrote:
Many thanks yet again for all of you that gave me advice/encouragement
during the build of my 50 square metre pyramid roof.
Its finished-and it does nt leak!!!.

Any chance of some photos? It sounds like a very interesting building !
Yours interestedly,
Simon.

tom patton wrote:

Did you have to incorporate thermal expansion sections ?
No expansion sections although the pyramid is free to expand and contract as
it is raised on a 600mm high upstand the perimeter drain similarly can move
horizontally.

and what is the
colour of the gel coat?
Can be any colour you like, though it's probably wise not to choose
black - the roof will probably get a bit hotter than white.
Gel coat comes in standard grey which suited me as it matches zinc.
There is a bewildering choice of many shades-at least 30.

And you can get process colours - Cyan, Magenta, Yellow, and Black.
From which you can make any colour you like.

Gel coat comes in standard grey which suited me as it matches zinc.
There is a bewildering choice of many shades-at least 30.

And you can get process colours - Cyan, Magenta, Yellow, and Black.
From which you can make any colour you like.
Gel coat should be applied no thicker than 1/2kilo per square metre it
contains wax so once its on you cannot bond to it so you need to grind back
to the base coat.
Gel should go on when base coat is just set-but-I had to overcoat some bits
2 weeks later-seems ok.

Aparently a pyramid fibreglass roof is rare enough for the building control
officer to pay me a visit he was well impressed-gave me lots of practical
advice on my soon to be dug soil drain.
Where can I post the photos----------.
wrote in message
ups.com...

tom patton wrote:
Many thanks yet again for all of you that gave me advice/encouragement
during the build of my 50 square metre pyramid roof.
Its finished-and it does nt leak!!!.

Any chance of some photos? It sounds like a very interesting building !
Yours interestedly,
Simon.

tom patton wrote:
Gel coat comes in standard grey which suited me as it matches zinc.
There is a bewildering choice of many shades-at least 30.

And you can get process colours - Cyan, Magenta, Yellow, and Black.
From which you can make any colour you like.
Gel coat should be applied no thicker than 1/2kilo per square metre it
contains wax so once its on you cannot bond to it so you need to grind back
to the base coat.
Gel should go on when base coat is just set-but-I had to overcoat some bits
2 weeks later-seems ok.

The wax floats to the top of the basecoat, and forms a skin.
This leaves you with a wax skin over the fiberglass, which excludes
water, and lets the fiberglass set.
In damp weather especially, fiberglass doesn't set all the way up to the
top, and goes sticky without a gelcoat.

You can clean off the wax, and bond to this, in theory, but it's problematic.
An excellent tool for cleaning off the gelcoat is one of those carbide
donut thingys that fits onto an angle grinder.
And a breathing mask, or something.

Owain wrote:
Ian Stirling wrote:
Gel coat comes in standard grey which suited me as it matches zinc.
There is a bewildering choice of many shades-at least 30.
And you can get process colours - Cyan, Magenta, Yellow, and Black.
From which you can make any colour you like.

Does it have to be applied as a sheet, or could it be dotted on with a
small brush?

I was just thinking of a self-coloured fibreglass roof mural. Or, as
it's approaching that time of year, internally-illuminated 8' high reindeer.


It's basically like painting with thick honey.

That gradually, over the period of a few minutes to hours sets.
You can in principle colour any part of the fiberglass, however, I'd
start with laying up the glassfiber sheet in clear, and then
a white layer to keep the UV out of the middle layers, where it's not
wanted (UV causes yellowing, and eventual failure).
Then paint with pigmented resin a design, followed up by clear gelcoat
once it sets.

(My fiberglass experience is limited to repair, and putting on black
gelcoat to an already existing fiberglass pond liner - it's still there
several years later, as good as it looked at first)

It's basically like painting with thick honey.

For making any structure like a reindeer-tank-spitfire-santa-ice cream
van-that would be an interesting roof ornament--you would need a very
different resin from roofing resin.
Roof type never gets glass hard and its got uv resistance.
Usually for structures you use polyester resin and in terms of cost-chopped
strand matt up to 600 gram per square metre-woven roving is next up in cost.
In summer you wont get much more than one hour usage of resin-in my
experience 20 minutes is about it.
Brushing resin is pretty useless as the resin must be forced into the matt
hence rollers.
I built a recumbent trike from glass reinforced plastic using woven roving
and epoxy resin.
It has suspension all round 63 gears and folds used it for 15000 miles so
far all over Europe-so GRP is serious stuff.
Quite happy to email pics of the trike in action---oops strayed far from the
pyramids.


That gradually, over the period of a few minutes to hours sets.
You can in principle colour any part of the fiberglass, however, I'd
start with laying up the glassfiber sheet in clear, and then
a white layer to keep the UV out of the middle layers, where it's not
wanted (UV causes yellowing, and eventual failure).
Then paint with pigmented resin a design, followed up by clear gelcoat
once it sets.

(My fiberglass experience is limited to repair, and putting on black
gelcoat to an already existing fiberglass pond liner - it's still there
several years later, as good as it looked at first)

In article , "tom
patton" says...
Aparently a pyramid fibreglass roof is rare enough for the building control
officer to pay me a visit he was well impressed-gave me lots of practical
advice on my soon to be dug soil drain.
Where can I post the photos----------.

On your blueyonder webspace.

tom patton wrote:


It's basically like painting with thick honey.

That gradually, over the period of a few minutes to hours sets.
You can in principle colour any part of the fiberglass, however, I'd
start with laying up the glassfiber sheet in clear, and then
a white layer to keep the UV out of the middle layers, where it's not

For making any structure like a reindeer-tank-spitfire-santa-ice cream
van-that would be an interesting roof ornament--you would need a very
different resin from roofing resin.

Roof type never gets glass hard and its got uv resistance.
Usually for structures you use polyester resin and in terms of cost-chopped
strand matt up to 600 gram per square metre-woven roving is next up in cost.
In summer you wont get much more than one hour usage of resin-in my
experience 20 minutes is about it.
Brushing resin is pretty useless as the resin must be forced into the matt
hence rollers.

I wouldn't dream of trying to wet out the matt with a brush, a roller must
be used of course.

However, once a smooth surface is obtained, you can then paint on
it with gelcoat quite easily.

Ian Stirling wrote:

Then paint with pigmented resin a design, followed up by clear gelcoat
once it sets.

The gelcoat won't set if its exposed to the air and will forever
remain tacky and prone to damage.

Applied to a mould and then overcoated by a conventional resin and mat
layup its not a problem, but if its used as a top coat, and not
formulated as such, then you need to add a specified wax solution
(available from most resin suppliers) to make it go off.


--

Matt wrote:
Ian Stirling wrote:

Then paint with pigmented resin a design, followed up by clear gelcoat
once it sets.

The gelcoat won't set if its exposed to the air and will forever
remain tacky and prone to damage.

Applied to a mould and then overcoated by a conventional resin and mat
layup its not a problem, but if its used as a top coat, and not
formulated as such, then you need to add a specified wax solution
(available from most resin suppliers) to make it go off.

True, I was assuming a gelcoat with wax added, sorry.

Owain wrote:
Ian Stirling wrote:
I was just thinking of a self-coloured fibreglass roof mural. Or, as
it's approaching that time of year, internally-illuminated 8' high reindeer.
It's basically like painting with thick honey.

So it would come out a bit impressionistic?

Well, it is runny enough that it will smooth out, unless you paint it on
just before it sets in the very hot.

I think that could be kewl - stained glass for the 21st century.