Roofing membrane full of black mould, what to use to remove it without damaging anything?

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Had a re-roof about 5 years ago, and the roofer never fitted any ventilation at all, so within a few months, it was soaking wet with condensation and the mould set in. I have since installed plenty of ventilation, which works well, but the mould still remains. I have emptied the loft, for removal of a chimney from a first floor bedroom (it's gone from loft and roof), and I want to get rid of the mould while the loft is empty. It is just the standard white roofing membrane, and I wasn't sure if the bleach based stuff would corrode it over time, plus I already know that it will corrode any nails holding the roof timbers in place, so want to avoid that.

I also have some kind of white mouldy looking stuff in some of the timbers that used to surround the chimney.

Does anyone know of any strong mould removal chemicals that will not corrode the membrane and the nails? I found one on screwfix, by a company called Scrubb, which is bleach free, and I emailed them but they didn't reply. Anyone used this? 'Scrubb Mould Shield bleach free mould killer and inhibitor'. Or any recommendations? Thanks.
 
For the black mould any of these should do,
The white mould is probably either some sort of fungus or perhaps just efforvessence from the brick work
Fungas treatment or just a stiff brush.
Pics would have helped.
 
For the black mould any of these should do,
The white mould is probably either some sort of fungus or perhaps just efforvessence from the brick work
Fungas treatment or just a stiff brush.
Pics would have helped.
I don't want to use chlorine/bleach based, as I mentioned in my post, because of too many structural nails nearby, and I don't want to risk damaging the membrane. I have searched, but I am asking if anyone has used any non-chlorine based, mould removing products in particular, in this situation, where chlorine based mould killers can't be used, and what did they use? Stiff brush won't do it, as the mould is deep in the fibres of the membrane, and it has been wet and dried out many times before the ventilation went in. Needs to be a liquid to soak in, I reckon.

Yes, the white could be from the brickwork around the chimney, but there is also the same white stuff elsewhere, that isn't near any bricks or mortar. Here's some photos, so you can see, thanks.

Round the chimney opening.
IMG_4014 2.jpg

Left hand side of chimney opening.
IMG_4016.jpg

Ridge. It's a dry fix ridge now, but was concrete and mortar from the 50s onwards, and there was some leakage about 10 years prior to the re-roof.
IMG_4019.JPG

A rafter. There's a few like this, nowhere near any mortar or anything that might do this.
IMG_4023.jpg

Near the bottom of the chimney opening.
IMG_4018.jpg
 

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