Damp and mould on new dot and dab boards

#1
Hi all. Looking for advice please...

Builders just completed a rear extension - block built cavity wall. They dot and dabbed standard plasterboard (paper backed) to all the walls in this area before the rear French doors were installed. The sides of the head and reveals were protected with plastic sheeting, but that's about it. The house is undergoing major renovations and has no heating currently. It was a wet period when this was done (a few weeks ago now).

After the doors were fitted, we returned to the house about a week later and noticed damp spots where the dabs had starting to leach through, all of which had black mould spots dotted across the surface. This was about 2 weeks ago.

We cleaned off the mould as best we could with an Anti-mould spray and damp sponge, and put a dehumidifier in the room plus a small convector heater. This seemed to keep the worst of the mould at bay over the weekend when we could be in the house running the heater and dehumidifier. But over the week when it's unoccupied, the mould returns. Not as bad as it was, but definitely coming back.

The builder claims this is entirely normal and admits no liability. That we should keep heating/dehumidifying and just carry on wiping any mould away as it appears until it's all dried out. Since some of the mould is ingrained into the board and doesn't wipe off (faint admittedly), that's not exactly plausible.

So... is our builder correct? Will I be wasting money in getting skimmed now if there's an inherent problem that won't go away with mould growth?
 
#3
If only I had any capital leverage left to apply... We'd signed off and settled the final balance before this was spotted (no pun intended). Live and learn...
 
#4
Out of interest... what would be considered a good practice approach that should have been followed? Or perhaps more importantly, regardless of who ends up correcting it, what should we be doing now to fix it?

e.g.

1. Remove existing
2. Sand/cement mix bonding coat
3. finish top coat

or

1. Remove existing
2. dot and dab foil backed board
3. finish top coat
 

Marshy

Private Member
#5
I'd ask to take some compo on his wife not being funny it's the same old usual crap from newbies when it all goes wrong !!?? Like I give a f**k dickwad
 

algeeman

Private Member
#6
If only I had any capital leverage left to apply... We'd signed off and settled the final balance before this was spotted (no pun intended). Live and learn...
"if only i had any capital leverage left to apply...."

where im from its
"the dosh has gone"
 

flynnyman

Private Member
#8
Out of interest... what would be considered a good practice approach that should have been followed? Or perhaps more importantly, regardless of who ends up correcting it, what should we be doing now to fix it?

e.g.

1. Remove existing
2. Sand/cement mix bonding coat
3. finish top coat

or

1. Remove existing
2. dot and dab foil backed board
3. finish top coat
Put some pics up? I take it the roof was off for a long time and the walls got soaked aswell as the insulation in the cavity?
 
#10
haha - no offence. I've been called worse. I am a newbie here, and yes I am asking for advice.

I'll get some pics tonight, and yes the walls definitely got wet before the roof went on. I know over time it will dry and it's definitely made progress in that respect. It's more the fact that mould hit us before it got a chance to dry and is proving a little persistent, and whether we have a genuine case vs. our builder for either rushing to get boards up, or not applying the correct materials/solution to avoid subsequent problems. The stuff I put up myself (same standard boards and dot and dab) in other parts of the house has been fine (touch wood) so far.

I'm hoping a PVA mix after liberal mould killing spray is enough to get on with things.

Pics to come...
 

bopper

Active Member
#13
Hi air walker,reading through ur post I'd say the cavity insulation got wet and is drying out causing condensation leading to black spot Mold you are doing everything right with dehumidifier etc you also need to let some air in aswell to circulate just takes time,I personally wouldn't of put boards up with no roof on ,did the boards get wet aswell ?do you know what cavity insulation was used? If you get those pics up you will get the answer here once the crazy gang get a peep at them!
 
#17
Here we go, lighting isn't great. The discoloration is from the anti mould cleaning rather than because they feel damp (they don't currently). A couple of close ups showing a few spots where the black dots are showing up again. Obviously it was far worse than this originally.
20170314_190922.jpg

20170314_191008.jpg

20170314_191105.jpg
 
#19
Was thinking I could create a nice texture finish using that. Bit more surface area for those mould spores to bite into.
 

Vincey

Private Member
#27
@Airtalker if you are in Midlands I can sort all this I'll rip it all out redo it to a smooth flat matt finish approx £700