Baffled!!

[Oneeyey]

Hi guys... dot n dabbed a concrete block pillar 3 week ago... i put foil back on first with foam 1 mtr high .... now getting this black mould dampness type of thing ... only on 2 sides of the pillar (see pic) any ideas why .... ????

 

[zolco]

Why would you dab foil backed boards?

 

[Djr]

Dabbling foil backs is a no no

 

[Oneeyey]

I foamed the foil back ... but dabbed over them with dry wall ...

 

[zolco]

That's still dabbing, but i have no answer to your question that why it got mouldy

 

[Natwasere]

Leaving plasterboard un plastered and unpainted on walls does seem to go mouldy if left long enough, guessing because it's porous and also paper and will usually do this where there is any sort of moisture (condensation areas like windows and corners, where dabs are etc)...... clean it and coat it

 

[Natwasere]

Oddly though if you leave it skimmed and un painted it don't seem to do it.

 

[Oneeyey]

Right ... ive foamed foil back to the block pillar ..... then ive dot n dabbed over the top of the foil board ...any ideas ...

 

[John j]

The plaster boards had not got damp or been stored some where damp before you used em

 

[Natwasere]

The plaster boards had not got damp or been stored some where damp before you used em

Did you mean to disagree?

 

[choppa]

Probably where you dabbed it's gone mouldy though the board from the moisture. Why have you dabbed onto vapour board?

 

[John j]

No

Did you mean to disagree?

No just seen this on boards that had been stored in a barn for a few years

 

[Oneeyey]

Probably where you dabbed it's gone mouldy though the board from the moisture. Why have you dabbed onto vapour board?

I used foil first to stop any moisture coming from the block .... then ive had to build out with large dabs to match the measurment at the top of the bulk head

 

[Wayners]

It's surface mould from a cold spot. Use that plasterboard with foam backing and stick on with foam board fix. This will stop it. You can buy from most supplies inc B&Q...

 

[McPlaster]

Moisture from adhesive perhaps, not vented in order to dry.

 

[Oneeyey]

Possibly mate ... good shout