What are these whits spots in my attic?

[vincenzo78]

Hi All,

I'd appreciate some views on what these white spots are, what I need to do to remediate and should I be concerned?

 

[footprints]

Looks like white mould usually due to condensation/ lack of ventilation. Try to increase the air flow in the loft.

 

[datarebal]

yes looks like that to me too.

 

[Alastairreid]

Ditto, condensation...

 

[catlad]

I'm not 100% sure its condensation, you get similar marks left on the timber work
when a roof has been relayed after it had originally been slated& torched.

 

[^woody^]

Salts from the nails reacting to a bit of moisture

 

[vincenzo78]

Thanks for the replies. I'm going to replace the loft ladder and fit slate vents front and back. Hopefully this will resolve the problem. If not then I'm not sure what else I can do. The insulation is pretty good and eaves are clear.

The evenly spaced white spots made me think it might be something else other than poor airflow causing it but the above work isn't going to do any harm regardless.