Builder payment for mouldy plaster

[Lola Giwa]

Hi all, just a sense check please.

Summary: should a builder charge to remove mouldy fresh plaster and redo?

We've had a kitchen extension done where we had the builders give us a shell with electrics and plumbing. Costs have been added as we've gone on and we have accepted them as we have gone despite lots of them being forseeable. We've always had a damp wall/chimney breast that we thought was due to a leaky chimney so we had them remove the breast and the stack. I noticed the party wall plasterboard was mouldy and pointed this out to him (he didn't notice/ignored and didn't tell us) and he said he had no idea and thinks it might be the neighbour's having a leak (they have since investigated and their side is dry). We said they shouldn't plaster this whilst we decide what to do but he didn't pass on the message and it was skimmed. The plaster is now mouldy and as discussed with him previously, we've asked him to remove the plaster so we can investigate, sort, tank and he can replaster. Should he charge further for this or should it be covered as we wouldn't have had him dot and dab if we knew the wall was still damp?

Thanks all.

 

[^woody^]

No

 

[oldbutnotdead]

If you have any evidence (text, email) that you told him not to skim (or dot and dab, your story is changing) you'd be in with a shout. Otherwise you'll have to just suck it up

 

[Lola Giwa]

If you have any evidence (text, email) that you told him not to skim (or dot and dab, your story is changing) you'd be in with a shout. Otherwise you'll have to just suck it up

We only realised the wall was still wet after he had already dotted and dabbed(dot a dabbed?) So asked him not to skim. We do actually have a taxt of that. We want him to remove the plasterboard too. Particularly as he would have seen the wet patches but still let the electrician carry on finishing first fix

 

[oldbutnotdead]

You need to talk to him then. Sounds like you are on the hook for the tanking, new pb (materials and labour), he should cover the skimming cos that's his mistake, the original boarding was as per contract.
Edit You can save yourself some money (and maybe improve the chances of getting a mutually satisfactory outcome) by removing and disposing of the mouldy board and adhesive yourself (if you have the time, strength and tools)

 

[mrrusty]

Chimney breasts are notorious for damp. Partly because uncapped chimneys let a lot of water down in to the fabric of the building and partly because combustion products from burning coal over many years react with lime particularly but other building materials too creating salts that "poison" the bricks. These salts are hygroscopic - they attract moisture from the atmosphere.

When you dot and dab or replaster, the water in the dabs or plaster draws salts out the wall, and as that water evaporates on the surface, the salts are drawn to the PB surface where they continue to draw moisture out the atmosphere causing crystals (efflorescence) and damp patches.

A good way to isolate walls around chimneys is to use metal top-hat section battens fixed to the wall and fix the PB to that.

 

[Notch7]

Hi all, just a sense check please.

Summary: should a builder charge to remove mouldy fresh plaster and redo?

We've had a kitchen extension done where we had the builders give us a shell with electrics and plumbing. Costs have been added as we've gone on and we have accepted them as we have gone despite lots of them being forseeable. We've always had a damp wall/chimney breast that we thought was due to a leaky chimney so we had them remove the breast and the stack. I noticed the party wall plasterboard was mouldy and pointed this out to him (he didn't notice/ignored and didn't tell us) and he said he had no idea and thinks it might be the neighbour's having a leak (they have since investigated and their side is dry). We said they shouldn't plaster this whilst we decide what to do but he didn't pass on the message and it was skimmed. The plaster is now mouldy and as discussed with him previously, we've asked him to remove the plaster so we can investigate, sort, tank and he can replaster. Should he charge further for this or should it be covered as we wouldn't have had him dot and dab if we knew the wall was still damp?

Thanks all.

The moral of this story is: get everything down on an an email.

builders have guys on site they want to keep busy so have a tendency to keep going and wish away problems.

this is very good advice:

A good way to isolate walls around chimneys is to use metal top-hat section battens fixed to the wall and fix the PB to that

modern plaster, whether board or wet plaster is hygroscopic and is easily damaged by damp, so isolation is the key.

 

[mrrusty]

this is very good advice:

thanks @Notch7. The irony is I only discovered this as a solution after having had the problem myself. A friend has already done this to good effect, but as yet I haven't done my own house where I learned all about this problem through first hand experience - crystals forming where dabs are 1.5m up a wall and around the chimney breast in a room that had had a coal fire every day for 100 years+ ! One day I might strip it all back and re-do it, but not yet...

I have found a reasonable temporary fix is to sand back and isolate the salts by painting on a dampseal paint (ronseal dampseal) before the room emulsion. The damp seal layer seems to be quite effective at stopping water vapour in the room air getting to the now salt-poisoned plasterboard and growing surface crystals.