Loft sarking board issues

Hi all,

Could somebody tell me how bad is the loft sarking board issue please? I went onto the loft the other day and there are a lot of white powder covering the boards. How big is the job to resolve this?

Thanks in advance
J

GundamWorld, good evening.

OK looks like an ex-local authority build???

The "powder" on the [what appears to be] Plasterboard is probably condensation?

From the notice posted on the purlin is there a load of insulation on top of the ceiling plasterboard? If so is it in any way "Drafty" inside the loft space, indicating an across roof ventilation??

In a heavily insulated loft space there has to be ventilation, in effect the loft should feel cold on a cold night, the ceiling mounted insulation is keeping the rooms warm. Problem arises if there is no adequate ventilation within the loft space? Water vapour permeates through plasterboard and insulation, but will condense within the cold loft space, and [possibly] cause the white powder to form as a residue

Problem you may have, is that if there is a high volume of air passing through the loft space then in really cold weather your C/Heating boiler could freeze up

Thanks for your reply KenGMac.

Will look into the ventilation problem. My other concern is that what if there was a leaking roof as some of the plasterboards look damaged along the gap (as seen from the photos)? How much do you think it would cost to replace them?

Many thanks

GundamWorld, good evening, again.

If you have a look on this board, in the section you posted this question, there are a series of "Pinned" posts, one is specific for "Loft Ventilation Answers" worth a look?

There are No indication of a roof leak, a roof leak will be a "concentrated" discoloration, indeed black with visual evidence of mould growth? what the images indicate is that there is a general spread of condensation having formed and dried of over a very large area.

As for the "damage" to the joint between two boards, bluntly, of no consequence at all, at all? was probably caused during construction??? leave alone, ignore it [please]

Ken

Looks like the usual white mold you get on sarking, appears as a fine white powdery deposit .

Thanks for your comments guys. Much appreciated. I have read some of the ventilation answers in this forum which is very useful. I guess once the ventilation has been improved the white powdery stuff should disappear. I just hope that the condensation is not coming from the roof via some leaked tiles. One question though, do you know what is the best thing to use to remove those white powdery salting without damaging the plasterboard?