white spots...like moss ? what are they? Information, help and tips on many areas of roofing including trusses, tiling, venting, insulation etc....

[vw754]

The loft in my semi (1930's) the beams and roof joists have white moss type stuff,more like spots of white,i wiped it a few weeks back but is now come back...what is it and what causes it? 2 beams have wet rot but only about 2-3 inch's long and 4 inch wide (not much i know) is it something to worry about ? ive treated the beams with cuprinol 5 star treatment,just concerned with the white spots.

loft has new insulation and is boarded up for storage use.
Roof is tiles that were cemented on in them old days so theres no felt.

[Joiner_Mike]

Hi how are you?
When rot occurs it is normaly due to one of 2 things. Ventilation or damp. Since you have just boarded you attic out it points me more to the ventilation.
All you need is better circulation of air in your attic so fix a few vents to solve this.