Roof leak causing rot

[Ed88]

Hi, I'm concerned we have mold/dryrot/fungi on the purlin and some rafters in the attic. We have what appears to be a leak on the valley, im wondering if this has caused the humidity to rise with it being summer and cause this. Could anyone identify or give some advice please?

Pics uploaded

 

[datarebal]

Nothing shocking.
Get the valley fixed including the felt. Give the valley rafter a dose of preservative while it's exposed .
And add loft ventilation .

 

[Ed88]

Do you think its fungus? It seems to be end to end of the purlin. Could you recommend anything to get rid that or do I just treat the rafter where the leak is with a general wood preserver? Screwfix have a sika wood preserver.

Would air bricks on the gable ends be enough or would you recommend something else?

Thank you

 

[Ed88]

I've treated the purlins with two coats of Sika Universal 5 Star Wood Treatment. I have also done one side of the rafter from top to bottom with treatment, I ran out so couldn't continue. I also got some 70mm soffit vents and put them on all around the house at 2m apart, I may go further and put more in at one metre. Also got someone to look into the ingress on the valley

 

[datarebal]

Sort the valley , vent and you'll have no problem air brick each end would be good