78 Damp - no problem

John (Adriatica) brought up the subject of damp in an earlier post. It is a bit of a soapbox topic for us.

We have restored two 400+ year old cottages in England over the last eight years. One was a timber-frame thatch and the other a mix of brick and timber-frame with a tiled roof. My husband is also a Building Surveyor so we have had a lot of experience with damp :!:

In both cases, the houses had no foundations or damp proof course and when we bought them, there was a lot of penetrating damp. If you listen to the 'experts' their answer is to inject the walls with a damp proofing material or to lay a new damp proof membrane under the concrete floors. Both of these solutions are invasive, costly and not especially 'green'.

This was our solution:

We lowered the general soil level around the houses so that damp earth was not laying on the walls. On one of the houses we dug a narrow trench around the building and filled it with gravel after having laid slate tiles against the house to prevent water laying against the walls.

We then removed the concrete render and replaced it with lime render and painted the outside with limewash. Lime actually draws the moisture out. We also used breathable paint on the inside of the house.

Guess what - in both cases the damp levels in the house fell to 'normal levels' :lol: Cost :?: - very little, just effort.

Old houses are always damp. Don't let it worry you, just use some common sense and you can control it. At one house the previous owners had laid a perforated house pipe in the flower beds against the walls of the house so every time they water the flowers, they watered the house and they wondered why the house was damp!!

Just a little note - I am not talking about dry or wet rot which must be dealt with properly by an experienced professional.

Category
Building/Renovation

Submitted by Anonymous (not verified) on Mon, 02/21/2005 - 04:02

The house I bought in Piemonte also has a wall that is rock [and soil] with permanent 'seepage' of water.

It seems that the normal solution to this problem in my area is to build a false wall a few centimetres [air gap] in front of the rock wall with a drain at the base of the air gap to take the water away - this gives you a new, dry, wall to decorate.

The system works in my house [it was put in about 25 years ago, and is still 'sound']

Submitted by Anonymous (not verified) on Tue, 02/22/2005 - 02:30

One wall of our house is damp due to the fact that water collected on the roof is conduited down through a duct in the wall to the water storage tank under the house. I had previously read in Johns post that lime mortar was probably the answer, the only trouble is I don't know where to buy it ........I mean I know it comes from the builders merchant but the problem is I haven't yet been able to find a builders merchant in or around Ostuni.....so, can anyone point me in the right direction please??

Submitted by Anonymous (not verified) on Tue, 02/22/2005 - 03:29

Sorry, I don't have much extra to add to the problem of houses built on wet rock. As far as I understand it, there is no easy solution, but I thought you might be interested in where to find info on lime plasters etc.

SPAB (Society for the Protection of Ancient Buildings - [url]http://www.spab.org.uk[/url]) does a great range of books and leaflets on it. It is a mine of useful information although it is aimed at the UK, lots of the information can be used by us 'new Italians'.

I am sure you can buy lime at the builders merchant but also try the agricultural supplies stores as it is used for some of the plant spraying recipes. Remember, lime in it's natural state is explosive stuff as when you mix it with water, a chemical reaction occurs.

Flyingveepixie - wouldn't it be better to line the channel in the wall? The guys that make copper guttering in your area could probably fabricate you something.

Submitted by Anonymous (not verified) on Tue, 02/22/2005 - 05:08

Hi Penny

Yes I thought about putting in a plastic duct or something similar for future prevention but the wall is in quite a bad state both inside and out as the damp has completely penetrated so I'll probably have to re-render on both sides.

Kenny