Wallpaper Mould/Mildew

[papermakerPGA]

Wonder if anybody has had any experience of our problem?
We recently fitted a new kitchen & subsequently tiled & wallpapered the walls, using 'Contour' type paper. Within ten days of papering we noticed patches of 'blue' appearing in a few places. On 2 walls the previous owner had fitted cork lining & papered over it, there was no visible problem. We steam removed the old paper down to the cork prior to repapering. One cork lined wall is an exterior wall & the other is on an internal wall.  The 'blue' spots are on visible on both walls.
Having removed the new paper from the worst affected area the mould is apparant on the cork.
Not previously having had any experience of cork on walls we are uncertain as to the cause of the mould - could it be a reaction between old & new paste, wrong type paste to use if cork fitted. Really need to know how to proceed to prevent recurrence.

 

[Musicmonkey<ADDRESS><STRONG>Musicmonkey<STRONG><ADDRESS>]

Could it be damp?  We suffer from humidity in our old stone house as apparently many do not having a damp course.  Do you have any ventilation?  It might explain why the previous owner put cork on the wall to act as a kind of barrier.

 

 

[papermakerPGA]

Thanks for that Musicmonkey - we feel that there is adequate ventilation with inbuilt vent in window, permanently open and an extractor over hob. If the marks only related to the exterior wall then of course damp would be most likely but having them on the internal wall also made us think of other alternatives.

[Rita]

Hi PGA,

Just a thought - You say you steam stripped the old paper off down to the cork tiling. Could this be your problem? as obviously cork holds water,damp etc. Did you allow the cork tiles to dry out sufficiently after using the steamer before re-papering? perhaps you could allow a while to ensure the cork tiles are completely dry prior to wallpapering again.

Other than that possiblity I am afraid I am unable to offer any other help. Let us know how you get on and if you manage to solve the problem.

Rita

 

[chirpy]

remove paper.

wash wall with fungicidal solution which should kill any spores if blue is a mould growth but before doing this

look at blue using a magnifying glass and if you can see a growth stucture then its mould-if not could be a copper salt leached out of wall-who knows?

let wall dry out for a week .

seal cork with a varnish or sealer - at least 2 coats-solvent based type- to try and seal in any spores that were not killed off.

then repaper but ensure you buy a wllpaper paste that contains fungicide. if paste does not then it will support any fungus growth as paste is normally made with a cellulose which especially in kitchens or bathrooms ie damp places is a danger.

also suggest applying a clear silicone treatment to outside wall in case water is entering through the wall and extracting any more blue fungus or stain onto wallpaper.

you should be able to buy all products in france

goodluck

[Gyn_Paul]

Not sure what you mean by 'contour' paper: is it a vinyl?

If it is, and the previous covering was an ordinary, porous paper, then I think you might have identified the problem. 

Either water vapour was leaching through the wall, the cork, and the paper and evaporating (I suspect that the cork may have been keeping it to a minimum), or possibly the steam-stripping has taken off a sealer coat on the cork and it's now much more porous than it previously was.

what are the walls made of?

Is this an old building ?

is there a known good DPC?

is there any obvious cause of damp (soil piled up against walls, garden level higher than the interior level, leaking or missing guttering) ?

unless there is an obvious source of external water getting onto the walls I would think carefully before sealing the exterior walls of a building without a DPC as - if the walls themselves are 'wicking' water out of the ground - you stop it evaporating to the exterior and risk making the problem worse inside!

 

paul

[papermakerPGA]

Many thanks to you all for your suggestions and possible solutions. We are coming round to thinking that having used the steamer to strip the old paper we have caused problems with the cork - more likely to have degraded any sealer than left moisture in as it was well over a month before we repapered. We have removed one area of cork to have a look under and there are some mould spots there. We will now act on all the advice, prior to repapering, and let you know the final outcome. Again, many thanks for your most constructive help.

[papermakerPGA]

 I have waited 6 months after my remedial work was completed and walls re-papered before saying that the problem has been overcome! All the advice was followed - old paper completely removed, traces of paste scraped and thoroughly washed off all cork & plain walls, all surfaces
thorughly washed with bleach solution & allowed to dry. 2 coats of kitchen emulsion paint applied all over then repapered. Still looking good!! Considering original 'mould' appeared within 2 weeks of papering think the problem has gone. Once again thanks for all assistance hope this may be of use to anyone confronted with a similar problem.