mould on wall ... dodgy builder?

[handymags]

Hi,

this may seem like a silly question, but I think my builder has pulled a fast one and I want to get my facts straight before I confront him!

I (actually my builder!) knocked through from my kitchen into my downstairs bathroom a few months ago. Recently, I have noticed mould on a limited portion of the wall - only the external wall that was formerly in the bathroom.

I removed the skirting board to find that this area was obvious not flush with the kitchen wall and he attached plasterboard directly to the wall to even things up. This has now gotten damp as I don't have cavity wall insulation ....

So, the questions are:
- is he an a** or have I just been unlucky
- what can I do?

Thanks

M

 

[seasickstevie]

Depends what he quoted for, what you asked/instructed him to do.
What he charged you.
A cheap job gets cheap results.
Lots of things to consider.

 

[handymags]

wanted a proper job done ... not massive amounts of mould 3 months later ...

 

[Symptoms]

mags - mould & damp? Have you checked the obvious possible causes for the moisture, leaking water pipes, dripping waste pipes, rainwater pipes on the outside of the wall, blocked (and overflowing gullies) outside? If the builder connected into existing supplies, or capped them off, during the conversion work did he make sure there were no leaks?

 

[^woody^]

Is this damp actually caused by the builders work - ie has he missed out a DPC or membrane of some sort

Or

Is it moist air from the combined bathroom and kitchen condensing on a cold surface?

The latter, I think. In which case is it the builders fault? He does not seem to have done anything structural to have caused water penetration, but rather, your change of use has upset the internal humidity levels

You may need to sort out some extract ventilation, or even have the cold wall insulated

 

[weseeyou]

mould is a living organism and needs ideal conditions to grow and spread. Changing your bathroom and kitchen could have changed your air low and other factors that have promoted mould growth.Mould growth generally requires moisure from condensation and a humid atmosphere. Can your kettle and cooking steam now get into the former bathroom?

You need to give more info. What happened to the bathroom? is it still functional ? or is it now part of the kitchen?
Do you have any heating in the bathroom ?
Do you have and use an extract fan in either the kitchen or former bathroom?
sorry woody missed your post whilst I was typing mine

 

[handymags]

there is no obvious leaks from anywhere - checked all pipes etc

I think it is unlikely to be due to change of use of the room as:

1) it is restricted to only a small area on the external wall and not on the joining wall (at the corner)

2) it is only where the plasterboard is - there is a clearly defined boundary between plasterboard/mould and perfect wall

I was thinking that since it's an old house (~1910) the external walls are not insulated and therefore, plasterboard should not be fitted DIRECTLY to the wall with no room for airflow

I hope this makes more sense!

Please help!

 

[^woody^]

It only takes a small change in relative humidity or air flow to cause condensation where non was previously

There is nothing wrong with fixing plasterboard to solid walls. In fact plasterboard will be a warmer surface and less prone to condensation than the surface of a solid wall

The bottom line is this - whilst you may have an argument that the builder has caused this by the work he did, there are several more likely reasons on why this is occurring and why the builder is not liable.

You could certainly ask the builder to rectify, but if he says "no" then it will be difficult for you to prove blame.

 

[weseeyou]

t
I hope this makes more sense!

Please help!

I have tried to help. I have asked you a few simple questions to try to aid me to diagnose your problem . I cannot see it for myself. You have chosen to ignore my request and offer of help and clearly have strong opinions of what is the cause yourself.
I am a Building professional and deal with mould and condensation problems on a daily basis for the past 30+ years but perhaps you know better than me

 

[handymags]

Hi Weseeyou,

it's now one bigger kitchen - the bathroom is relocated upstairs

I use an extractor fan whist cooking in the kitchen and I don't have a kettle

I appreciate your help!

Ta,

M

 

[weseeyou]

as far as I can see it is not the fault of the builder but rather a `lifestyle issue'
Nothing the builder is likely to have done has created the mould. Mould spores are in the air everywhere all the time in every dwelling. Whether or not they grow is up to the conditions you provide in your home to support mould.

By opening up your former bathroom to the kitchen space you have altered the original environment in both spaces.

How do you boil water tea/coffee etc ? microwave ? it still produces water vapour doesn't it !
Your kitchen produces a lot of condensation which supports mould but it is probably too hot to encourage spores to grow there. Whereas you may have a cold bridge in your bathroom space and the temperature may be lower which together with all the moisure you are putting into the air from kettle, cooking, washing, drying etc is providing ideal conditions for the mould to grow.

Look at ways you can improve the thermal insulation in the former b/room particularly if it has 2x or more outside walls and a poorly insulated roof


suggest you look at increasing temperature in former bathroom (,particularly at night time)increase ventilation when cooking and drying clothes and kill the mould with bleech efore it spreads and becomes unmanageable.
Plenty of help on condensation and mould on internet. Consult your local Envionmental health dept.

 

[handymags]

thanks everyone!