Mouldy beams

[Dianes]

We have owned our house in Brittany for nearly 5 years now.  When we first bought it there was quite a bit of mould on the wallpaper, which we stripped off throughout.  There was a bit on one of the beams.  We then totally re-plastered, decorated, cleaned, etc.  For the past 3 years we have been renting it out in the summer months.  It has never smelled damp even after 2 - 3 months being shut up.  We do leave the plastic tubs with crystal salts in each room when we shut the house up, and they are always full of water on return.

On our last visit a couple of weeks ago we discovered quite a bit of mould on the beams and even on some of the wooden furniture.  We didn't notice it when we were there in early July, and since then the house has been continually occupied with guests, so you would have thought it was pretty much aired.  However, this summer has not been as good as the previous ones.

Does anyone else have this particular problem, and how did they solve it.  I am loath to keep a dehumidifier on when the house is shut up, as we prefer to turn the electricity off.  The salts have done a good job up until now.

I cleaned all the beams with Mould and Mildew spray (horrible job) and not sure if that was the right thing to do.  The beams are stained or varnished dark brown.  Is there anything else I could use to prevent more mould?

Thanks for your help,

Diane

[powerdesal]

[quote user="Dianes"]

We have owned our house in Brittany for nearly 5 years now.  When we first bought it there was quite a bit of mould on the wallpaper, which we stripped off throughout.  There was a bit on one of the beams.  We then totally re-plastered, decorated, cleaned, etc.  For the past 3 years we have been renting it out in the summer months.  It has never smelled damp even after 2 - 3 months being shut up.  We do leave the plastic tubs with crystal salts in each room when we shut the house up, and they are always full of water on return.

On our last visit a couple of weeks ago we discovered quite a bit of mould on the beams and even on some of the wooden furniture.  We didn't notice it when we were there in early July, and since then the house has been continually occupied with guests, so you would have thought it was pretty much aired.  However, this summer has not been as good as the previous ones.

Does anyone else have this particular problem, and how did they solve it.  I am loath to keep a dehumidifier on when the house is shut up, as we prefer to turn the electricity off.  The salts have done a good job up until now.

I cleaned all the beams with Mould and Mildew spray (horrible job) and not sure if that was the right thing to do.  The beams are stained or varnished dark brown.  Is there anything else I could use to prevent more mould?

Thanks for your help,

Diane

[/quote]

Definitely sounds like mildew. Apart from the use of  Anhydrous calcium chloride salts the basic need is ventilation. The summer has been wet with warm spells, that means moist air in the house and, without adequate ventilation, that is a classic recipe for mildew.

Can you improve the natural ventilation when you leave the house empty, without prejudicing security? Increase the amount of anhydrous calcium chloride, perhaps in bigger trays? The mould & mildew spray is a valid treatment but given the right air conditions mildew will appear because spores are all around in the air.

See this quote:- Mildew thrives in moist areas, where humid air settles on a cooler surface

and where temperatures range between 40 and 100 degrees Fahrenheit. It is

attracted to surfaces where there is a nutrient base (and virtually all

surfaces contain nutrients) and where there are already mould spores. Although

thorough cleaning and the use of disinfectants can provide some protection

against mould growth, mould spores are around us wherever we go, and virtually

all construction materials and household furnishings can provide the nutrients

necessary to support the growth of mould.

[Gluestick]

When we bought it, our house had been left unnocupied for considerable lengths of time, with short stays in between.

It was very hard to get rid of not only the mildew, but the awful sweet smell!

The  secrets were: cross ventilation by installing air vents, which were left open 365 days per year:

Heat!

Treating ALL affected surfaces with bleach.

Stripping off endless layers of vinyl paper: it doesn't breathe.

A large commercial standard de-humidifier which is turned on only when we are there and moved around the house until the ambient humidity has signficantly reduced.

ALL furniture we inherited had to be emptied, taken apart as far as possible and scrubbed out with bleach.

Seems to have worked.

The mould spores from mildew are serious: having a mild respiratory problem, I was quite badly affected.

Mildew can be serious for asthmatics.

 

[Dianes]

Thank you both for your replies.

Yes it was mildew.  But luckily the house didn't smell, and none of the guests complained.  We'll be leaving the salts out again when we close up, but it's not really practical leaving them out when we have guests. I'm not sure about how we can ventilate the house, whilst keeping it secure, but we can think about that. We don't have central heating, but the place soon warms up when we are there with electric heaters and the wood burner.

As for bleaching everything, I worry about what that may do to the furniture, and especially the dark stained beams.  Some of the staining came off with the mould and mildew stuff.  Apart from that the beams are very rugged and craggy in places, and not easy to coat thoroughly.  Is there any non-bleach treatment that repels mildew?

Hate to think of being surrounded by mildew spores.

Diane

[Gluestick]

Diane, last month, of all things, I sorted an old corkscrew, made from vinewood! (bought the house with all the contents: and I mean ALL the contents!

As you know, vinewood is craggy, to say the least: despite repeated washing, the nasty mould smell persisted.

Soaked in strong bleach and scrubbed: and then had to re-varnish.

Doesn't smell now.

Bleach kills the mould spores; little else really works.

I've head tales of using TCP, hairdressers peroxide, Milton Fluid etc. Best seems to be bleach.

Ventilation: best way fit air vents just above the skirting tiles. leave doors open to promote air circulation.

Worked for me!