Cannot get damp out of walls...

[MrCanary]

Over the last three years, we have been spending oodles of cash renovating our small, 200-year-old farmhouse in Indre et Loire. Totally rewired, new plumbing, new windows and doors, new roof and all the old rendering taken off the outside walls, with the original stonework being professionally treated. Plus, of course, the customary eight layers of wallpaper stripped from all the interior walls!

But do you think we can get rid of the damp in the lower parts of the walls - especially the kitchen? No!

It has been suggested that it happens because the house is shut up for long periods of time (2 months max) and if we were there full-time, it wouldn't be a problem, but I'm not so sure.

Anyone got any thoughts/similar experiences please?

Thanks...

 

[Blanche Neige]

some suggestions:

It's saltpetre (sp)

The stones are malade so there will never be a cure!

"It has been suggested that it happens because the house is shut up for long periods of time (2 months max) and if we were there full-time, it wouldn't be a problem, but I'm not so sure."

Yes this could be a contributing factor. If it is possible to leave some heat on in the house albeit on a very low setting this will make a big difference, also leave dehumidifiers around the house, and leave all internal doors open while the house is shut up.

When you are there during good weather air the house by leaving doors and windows open as much as possible and let the sunshine in.[:)]

Toile de verre is probably the only sort of "paper" that will stay on the walls and we have used this to good effect.

 

Finally, you are not alone and many (French) people accept this as a way of life and just live with it!

 

Bon Courage, I am sure others will have some good suggestions.

[Ron Avery]

If it is a stone wall with lime/debris/sand filling soaking up the water in the ground, the damp will always be there up to a metre, it  is natural in winter because that is how stone walls work, there is no damp course.

 The only effective way of stopping this AFAIK, is to seal the interior wall with a waterproofing treatment, not cheap or pretty if you have exposed stone, but effective.  You can then plaster or crepi over it, or waterproof and then dry line the affected walls.

[Charlotte3]

I commented on exactly this to the guys in work when we were decorating an old renovated stone built house.

The builder pointed out a line which, when you knew to look for it, actually ran right the way round the house. The damp rose as far as this line, but not over it.  He told me that very stone built house has a natural level of damp, which may or may not dry out with heating, weather conditions etc. but was certainly nothing to worry about...he, of course, was French!

Our own 200 year old house has always had damp in the front wall, but we put this down to the fact that the pavement is higher than our floor level, so rainwater gathers there, also a leaky gutter above not helping.

However, since our neighbours moved out about a year ago, we also have a high level of damp (about 3 feet) in the adjoining dividing wall. We're hoping to have a word with the new neighbours when they move in. It wasn't there before the house next door was empty.

Apart from heat and ventilation I don't see how you can get rid of it completely, I rather think it's a natural thing with these houses.... we lived in a 400plus year old stone built cottage in N.Ireland. It was listed and every possible renovation had been finished, and we had horrendous damp rising in the sitting room, despite central heating.

Aly

[Anton Redman]

Things that helped us :  Install Gutters  and drains so rain water does not bounce off tarmac onto the outside wall. Scarped down soil by between 15 and 25 cetimentres where is had built up in the front garden over the years. Capped the chimney and started using a wood burner. Being there full time also helped

We still ended up drylining a small section of the kitchen wall leaving a air gap and some descret ventilation behind.

[cooperlola]

When we first moved in here, the house had been empty for about 6 weeks.  It felt a little damp (nothing obvious).  Just a week after we'd moved in, with the central heating going and having aired the place a bit, the vaguely musty smell went and we've had no signs of this since. 

Another thing, were the interior walls re-rendered at all?  It can take up to a year for some of the residual moisture to go, if chaux (lime plaster) has been used, so I'm told.

[friend of stouby]

As Anton has mentioned previously, we also use a large wood burner and this has been the largest single factor to drying our cottage out too (walls and floors). We are in France for about every other 2 months, so the interior heats up and cools down, not the best. While we are there, the wood burner manages most of the damp to the point that within 3 or 4 days of arriving the humidity is at just the right level and the floors and walls are noticably drier. On leaving the property we leave the stove door and a cleaning hatch for the chimney open. 

After installing the wood burner, we found that when we returned that damp was still obvious but to a lesser degree. We then removed soil piled against an end outside wall down to just under interior floor level, followed by installing through the wall vents on opposite walls in each room, one near to floor level and one nearer ceiling level. We now return to a cool but pretty dry house. The vents have insect screens and a slider for when it is really cold.

Two rooms have floors that were very prone to damp, which may be underground channels or even a water course (a tip picked up on this forum), but I guess that to make a long term cure there we will have to do some digging on the uphill outside wall to effect a really effective solution?

With the simple but very effective measures above our house has become very comforatble to live in although I'm sure there are other things that you can do to help as well.

Jamie

 

[MrCanary]

Thank you, all!

There is much advice there for my wife and I to consider, but most of all, there is a lot of reassurance. We thought our house was the only one in France that behaved like this - and yes, it never creeps above one metre. The saddest thing is though, it is making a mess of the leading edges of the kitchen fireplace. As has been suggested, perhaps capping the chimney and putting in a wood burner might help...

Thanks again!

[Gluestick]

I suspect that stone-built houses in France and very definitely Torshe - of which there are quite a few in the North -  "Die" if too dry. Same with flint cottages in Norfolk and the Wash, since the construction methods came from Holland along with the wetland reclaimers in the 18th and 19th cents.

Our house had musty smells and severe internal damp - we thought.

It was being closed up and no ventilation. Wall vents (again with bug screens) in two bedrooms and the corridor mainly sorted that.

A big dehumidifier - a proper one with a fridge pump -  does the rest.

When we go over soon, I know the tiled floors will be covered in condensation as the internal heat dries out the moisture and it lepas into the atmosphere and condenses on the floors!

However, once the dehumidifier has been on for a few hours, all will be well.

It is quite amazing to empty the tank and see how much water has been extracted in two hours!

So, take comfort, Mel. your house is quite normal.[:D]

 

[MrCanary]

Today, here in Norfolk, I mentioned this problem to my son's friend, a junior architect who works for a company that specialises in restoring old Norfolk properties including barns.

He confirms what people have said in this thread, yes this is quite normal and nothing to worry about, but there is a system his compnay uses to overcome the problem. They inject a silicone based liquid into the lower walls, both inside and out. This fluid soaks through the stone work, moving downwards and then sets which creates a barrier through which the damp cannot pass through from below.

I'm not sure how effective this is, but he says they have  not received any complaints from their clients.

[Nearly Retired (I am now)]

"This fluid soaks through the stone work, moving downwards and then sets which creates a barrier through which the damp cannot pass through from below.

I'm not sure how effective this is, but he says they have  not received any complaints from their clients."

.........YET!

:-) That's probably because they're all still in hospital after the house walls dried out and fell down.

[Gluestick]

Beat me to it Nearly!

Always amazes me how there are companies out there which make a businesess of "Solving" a problem and creating a whole load more in the wake of the "Solution"!

Mel: your house is quite normal. Leave well alone!

Yiou state that it is stone construction; ergo it will have been built with lime mortar.

If you dry it out it will fall down!

Injecting a DPC (Damp Proof Course) is a chemical method used to solve rising damp problems in conventional brick built houses, where the integrity of the original DPC, normally slate, has failed over time.

Whilst it is quite possible to replace the old failed DPC with a modern synthetic (bitumised plastic sheet) DPC, it is a very time consuming process involving taking out bricks immediately above the DPC and replacing them on top of the new barrier.

That's why checmical DPCs were invented. By injecting various chemicals an impermeable chemical barrier is formed which prevents damp rising up from the foundations.

However, this was not and is not intended to be used on old stone or flint (e.g.) buildings!

For further infofmation worth looking here:

http://www.periodproperty.co.uk/uncle042007.shtml#uncle042007-07

 

 

[MrCanary]

NR, Glue and Robin - thanks, I am taking it all on board!