flaky walls

[carlsquires]

Hi all, I have a house in sicily that im looking to fix up and let out over the summer. at the moment its in a reasonable state, just needs a little face lift.
But most of the walls in the first foot are like this...

//media.diynot.com/165000_164232_33714_48347735_thumb.jpg

obviously there is an issue with humidity/damp but i was hoping just to cover it up for the summer period and do some major renovations next year.
So what i've done is scrap away the badly affected areas and fill with a product called methyl-stick (wouldn't expect anyone to know what this is!) which seems very similar to easy-fill, i allowed it to go-off and applied a base coat of paint to the wall, but after a couple of days this began to happen....
//media.diynot.com/165000_164232_33715_52661936_thumb.jpg

In other areas the filler had began to crack and flake away from the walls.
I was careful to clean the affected areas free from dust/debris and made sure the walls were reasonable damp before i applied the product. I was advised that this was a suitable product for the purpose i required.
So i was wondering if there was anything more i need to do prep wise, or is there a bigger issue with the walls than i anticipated.
thanks,
carl.

 

[PrenticeBoyofDerry]

If you have damp issues with the walls, they need to be taken care of first.
Any remedial work done to the surface of the walls, whilst the problem still exists, is really a waste of time.
All you are doing is sealing an area where damp exists and this will only cause blister or flaking to your paint work.

 

[carlsquires]

thanks for reply, as im a complete DIYer when it comes to this sort of thing, would you have any idea what could be causing this problem as its present on every wall in the building (a single storey building). If so how could i treat it? thanks

 

[PrenticeBoyofDerry]

Need a bit of info, italian structures not my thing!
Has the property been empty for sometime?
How damp are the walls?
Is the damp at lower levels only?
Is it every wall including internal ones?
Is the roof in good order?
What are the walls built in, are they externally rendered, if so what condition is that in?
It may be a case of drying the house, humidity extraction and ventilations.
But could also be water ingress.

 

[carlsquires]

Lets see if any lf this helps......
The property has been empty for around six months, since being empty there was a mouldy smell around the house.
the walls don't seem too damp, but it's the first foot from the floor on every internal wall affected and but less so on the exterior walls.
its a mid terraced house around 100 years old (although the house to the left is a lot younger).
the roof to the right rear of the house seems to be leaking, signs of mould, discolouring on the ceilng.
i'm not sure what the the walls are constructed in but what i can tell from local building projects is the a reinforced concrete frame is made than the gaps are bricked up using hollow terracotta bricks, then rendered. whether this was practiced 100 years ago i wouldn't know. i do know the external walls are about 40cm thick and rendered which seems in tact, no cracked or loose bits, the internal walls about 15cm thick.

 

[dazdel]

Sounds like you have salt damp, also guessing you have no dpc. Without going into detail, if the walls are made of terractta bricks, there is not much chance of hacking the old render off without breaking the bricks, so next option is to remove the paint with a scabbler.

When the paint is removed wash down the render with a sponge, you will know the state of the problem by looking at the render, good chance that it will be flaky on the surface. After washing down let it dry out for a few days, and see if the salts come to the surface, they will only show when it's dry.

If the salts come back to the surface after washing, just wash down again and keep doing it until they stop. Once this is done you can put a fine skim,of these products, depending on the grain of your render, so you can get some sort of match to what you have.

If your walls are stone or block you can still use these products, or some lime render products, which you should be able to get hold of. Also remove the render for best results in this case



http://www.cercol.com/uk/index.php?pagina=prodotti_scheda_da_home&id_da_home=68



http://www.cercol.com/uk/index.php?...oria_scelta=Products for building restoration


http://www.weber.es/morteros-tecnic...atamiento-de-humedades/webertec-hydromur.html

 

[carlsquires]

thanks for the advice dazdel will give it a try!