Moss on recently replaced roof

[rubble2]

I know that there have been a lot of threads on a similar subject but I wondered if anyone could answer these specific questions please?

We had our slate roof replaced about 12 months ago (a lot of the original slate was reused, with new/reclaimed slate as required). No problem with the quality of the roofing work carried out, but have noticed a few patches of moss forming on both faces of the roof.

First question - is this necessarily a problem?

Second question - I don't recall seeing much moss on the roof before the roof was replaced, obviously the insulation was upgraded at the same time (superquilt) so could the resulting change in temperature of the roof surface be causing the problem?

Third question - If it is a potential problem what is the best - longest lasting cure?

Thanks

 

[Topof]

There is only one good philosophy to keep a roof for a longtime : Keep it clean.
The insulation should not affect the external envelope. There should be a ventilated gap above the quilt, so both sides of the slates are broadly at the same temperature.
There is no lasting cure. Slates have very little water absorbtion, so you already have a suitable material. Try Mossgo-Pro, with a surface biocide the roof undergoes a deep cleaning, and the product goes into the laps, killing some algae dwelling there. It is not permanent, but it will clean for the longest period of all the methods available.

 

[^woody^]

I don't recall seeing much moss on the roof ...... could the resulting change in temperature of the roof surface be causing the problem?

It's nothing to do with the temperature of the roof (its still very cold outside ).

If there really was no moss before, then the older slates have weathered to a more rougher surface which more readily allows moss to grow//grip, the new slates may additionally have a mineral within them which certain moss likes

It's not a problem unless the moss grows to an extent where it pushes the slates up

 

[smashngrab]

http://www.copperridge.co.uk/