Flat roof problems

[Henryv]

Warm greetings,
I am new to this section and would appreciate your guidance.
I need a new flat roof for both my garage and conservatory.
I am prepared to pay for the best.
I have looked at GRP, Evalon and Firestone EPDM rubber.
Which is the best? Or is there something even better?
They are both covered in felt at the moment, and the felt has a silicone paint solution on it.


Henry.

 

[cjard]

Not to be picky, but I seem to recall reading in some building regs document that to be a conservatory, the structure has to have a roof that is at least 75% light-transmitting.. A felted roof structure attached to your house might not be a conservatory?

 

[Henryv]

No, it is an old add-on, from before conservatories were popular.
Call it what you like - 'Garden Room'?
It has a flat leaking felt roof.


Henry.

 

[^woody^]

If you want to "pay for the best", then consider a gold leaf solution or lead or copper.

Otherwise EPDM will do

 

[Henryv]

Thank you Woody!

Have you come across 'Roofkrete'?
It looks good but an expert opinion would be very helpful.

Henry.

 

[^woody^]

No particular experience of roofkrete, but it looks like one of the newer liquid coatings of some sort - the ones that look like a tray of blancmange has been pour over the roof.

If so, I do know of this sort of product (although probably not actually roofkrete) on some high rise blocks which have experienced leaks since installation, and the contractors have been recalled several times under the 15 year warranty. But penetration points are hard to find.

Their site seems to have a lot of marketing spin, and I am dubious of the claims that this product will last the life of the building. That seems to be stretching things somewhat. Also, I did not see any BBA certification

But a 30 year [insurance backed] warranty would be good

 

[^woody^]

oops

not meant to be here

 

[Henryv]

Hi Woody,
I have contacted the 'Roofkrete' company and they descibe it as a reinforced, sand and cement, flexible membrane 7 mm thick.
They have just won the best Eco roof competion in the daily telegraph!

http://www.roofkrete.co.uk/html/compare_membranes.html


Henry.

 

[Xenon]

A sand/cement membrane does not have the expansion capabilities of Felt/Asphalt/EPDM. Its marketing cobblers.

High quality felts with an insurance backed g'tee are expensive, as is Permaphalt.

Don't know about EPDM as we refuse to install it after multiple failures. (Commercial)

You're looking at £50 a square metre for uninsulated premium felt.

 

[Mw Roofline]

Where are you based, Henry?

 

[Henryv]

I'm north Manchester.


Is Permaphalt better than GRP?
I suppose my question still is - which is the best.
Zinc, Permaphalt or GRP?


Henry.

 

[breezer]

its not zinc.

some basket will pinch it and sell it.

we had that in the "roof valley" as did all the houses in this rd, it only lasts about 20 years

 

[Xenon]

I'm north Manchester.


Is Permaphalt better than GRP?
I suppose my question still is - which is the best.
Zinc, Permaphalt or GRP?


Henry.

Permaphalt is modified Asphalt. You wouldn't put Zinc/Copper/Lead on your application. I would do it in felt.

 

[Henryv]

What is the best quality felt?
Something that will last a long time.
Every felt roof I have ever had has had a poor life and soon cracks and leaks.
Also - what is wrong with GRP?


Henry.

 

[Xenon]

These make the best felt in existence, but its only available to licensed installers.

Langley Siplast/Marley Goldseal are close runners. Marley is available from good roofing outlets, Asphaltic should have a branch up your way.

GRP fractures in a`short space of time if used over a large flat area. In the early 90's we spent nearly 3 years removing it from a number of schools that had had it installed, it had also allowed the structure under it to rot.