Mystery Light Brown Stains

bocon

We moved into our new house just over 12 months ago. It consists of a renovated 1970s Brick Built bungalow with two new extensions more than doubling the size of the house overall. We have trickle vents in all our windows which are kept open all year round as well as regularly opening the windows themselves especially during the warmer months. All the internal walls of the house are still just painted white (there is still plenty to do with the place before we apply finishing touches). The mystery light brown stains have started to appear on both new and pre-existing walls. The one in the image embedded (I hope I embedded it correctly) is the largest. No signs of mould in the corners of the ceilings (the kind of mould growth I'm used to in previous houses I have lived in.
Sent photo to the builder and he says lack of ventilation. Does anybody else have any other suggestions? 
I was hoping it might be some sort of reaction between the paint and plaster.
If it is caused by a lack of ventilation do we have any grounds for recourse with the Engineer or Architect in getting it resolved.
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bocon

[font=Verdana, Arial, Helvetica, sans-serif]2nd attempt at attaching photo[/font]
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Metric Tensor

You need to upload the image either as an attachment to your post or to an image hosting site like imgur and then provide a link to that.

bocon

[font=Open Sans, Arial, Helvetica, sans-serif]Attachment not found.[/font]

bocon

Attachment not found.file:///C:/Users/oconnb20/Downloads/IMG_0526.JPG

bocon

Metric Tensor

That works if I click on it OP!

Doesn't look like mould to me ... but I'm not sure what it is!!

bocon

http://imgur.com/CJWXXXZ

sydthebeat

i think theres some restriction to having an attachment until youve 50 posts, or something...

try uploading it to an image site (such as imgur) and post the link

bocon

Gave up on trying to embed the image. 
Posted it on Imgur (http://imgur.com/CJWXXXZ)_______thanks MT
Opinions and advice welcome.

sydthebeat

nevermind

cameramonkey

I cant open your picture links.

I moved onto a house that was not in great condition and had been lived in for many years by an old man.

I striped wall paper, cleaned walls and ceilings and repainted the entire house white. Within a few weeks brown stains began to appear through the white paint. It turned out that the previous owner had been a heavy smoker and the stains were from nicotine. I had to repaint the stained areas with oil paint and then paint with a white paint over that. That was the only solution that worked for me.

Metric Tensor

It looks like it must be moisture related.

What is the build up of the wall? Is there a cavity?

Edit: Actually I see that it's on both new and existing walls - which is a bit more confusing. I wonder was it painted very quickly after being skimmed? How long were you living there when these marks showed up?

derb12

Is there any pattern to the stains - do they line up along a stud for example? Perhaps the nails used to affix the plasterboard weren't the correct ones? I've also seen splotches like that on skirting and picture rails where there is a knot in the wood underneath.

bocon

The house is external wall insulation to marry the old and the new parts of the house.
All the cavities have also been pumped. 
Showing up on both external and internal stud walls so no pattern to it.
I think they started to show up around 8 months are moving in.

Metric Tensor

Is the plaster applied directly on to the blocks for the external walls or do they have plasterboard or dry-lining board between the blocks and the skim?

bocon

Plaster is straight onto the blocks.

Mickeroo

Just so it's easier to see.

bocon

Thanks Mickeroo for posting the photo.

Metric Tensor

So it's happening on both stud walls and solid walls and throughout the house.

Is there any pattern to the distribution. Are the mainly low down or high up? Any rooms that don't have them or any rooms that have more than others? What about the corridor? How about inside the hotpress?

Sorry for all the questions. It's unusual and yet I have this niggly feeling that I've seen it somewhere before but I just can't out my finger on it!

mickdw

Its occuring on new and old portion of the property and on areas where there are no screw or nail or other type of fixings within the wall. It would Appear that it can only be caused the the make up of the plaster. I think you are dealing with dirty /contaminated sand, skim coat or water.
The only thing ive ever seen that was anyway similar but much worse was skim that was mixed with water from a not quite clean barrel. It was noticeable day after being plastered though.

mickdw

Its occuring on new and old portion of the property and on areas where there are no screw or nail or other type of fixings within the wall. It would Appear that it can only be caused the the make up of the plaster. I think you are dealing with dirty /contaminated sand, skim coat or water.
The only thing ive ever seen that was anyway similar but much worse was skim that was mixed with water from a not quite clean barrel. It was noticeable day after being plastered though.

bocon

Don't mind all the questions. I'm delighted to get as much feedback on this as possible and will do all I can to answer your questions.
I've gone through the house now and can only find it in three rooms. The bathroom, utility room and the open plan which consists of kitchen, dining, living and play areas.
The bathroom was remodeled but some old stud partitions were retained. It is appearing both on pre-existing stud partition and new section. Don't use the extractor in the bathroom but do leave the window wide open after baths and showers.
Same applies for utility room which is a mix of old and new stud partitions. It has appeared on both. Clothes would be left to dry in the utility room and it contains a condensing clothes dryer, washing machine, gas boiler and water tanks. No windows in here so only ventilation is trickle vent on the back door. 
For the open plan area it's only occurring on the external walls so no sign of it on any stud partitions.

I suppose the fact that it's appearing on old stud partitions rules out the contamination in the plaster work.

sydthebeat

any chance of a photo of a whole wall showing any pattern?

mickdw

From earlier posts, i understood it was on plastered block walls.
If its on wall with any kind of metal fixings, they would be my first point of interest.
Gently dig out one spot - can be easily filled again. See if there is anything of interest beneath.

flutered

quite a lot of the staing on plastered walls is as a result of the plaz, so says the old time plasterers hereabouts, any walls plastered using washing up liquid have no red staining, are they correct, as this has only become prevelent since the boom years

dixiefly

Were the existing walls replastered? If so then were all of the walls concerned plastered?

Minute iron filings in the plaster is a possibility.

Metric Tensor

Youve just listed the bathroom, utility and kitchen.

These are the three wettest rooms in the house. So even though the stains are unusual I think there's a good chance they are somewhat related to the amount of moisture in the air.

Ventilation and a reduction in the amount of moisture you release would be my first step. There may be something unusual with the plaster but based on the rooms you've listed I'd say it could be reacting with moisture in the air. So my first steps would be the usual ones (these all make good sense in any house and you should be doing them anyway):



1. Always use your bathroom fan. The window will help too but the fan will do more unless the window has a big opening section that's fully opened and the wind is going the right direction.

2. Don't dry clothes on radiators or on clothes horses in the house.

3. Always use the extractor on your cooker hood.

4. Open the window when you are having a shower.

etc. etc. - you get the idea.

If you want to push the boat out a bit run a dehumidifier in the utility or bathroom for a while and see what happens. Of course the stains may never go now that they are there but you might prevent more from happening or they might fade.

Again ...there could be something awry with the plaster but the steps above make sense for all houses particularly those experiencing any form of staining in the "wet" rooms.

bocon

Thanks all. I'd say it's gotta be moisture related alright seeing as it's bathroom, utility and kitchen that are affected.
I would have been interested in installing a heat exchange unit in our build but could not stretch to it in the budget. Had it in the back of my mind that we could always look to do it further down the line as the house is a bungalow so all rooms have direct contact to the attic.
Does anybody have any strong feels for or against Heat Exchange Systems in general. The last thing I want to do is to put holes in the walls to allow for extra ventilation.