Damp in walls

[GarethEdwards101]

I have a problem with damp in my exterior kitchen wall, which has now affected the wooded kitchen units. The wall are made from slate two feet thick and the building is over 150 years old, the problem may be due to the outside ground level being higher than the internal kitchen floor. I have been advised that a new cream injected damp proof course will cure this problem. My concern is slate is not a very porous material and the injected damp proof course will not make any difference.

All advise is welcome.

 

[jellycat]

I would have thought that the solution would be to address the issue of the outside ground level being too high? Have a watch of this video about damp in old houses, it is very helpful:



http://www.spab.org.uk/blogs-videos-podcasts/

 

[ree]

You have penetrating damp - no injected fluid or cream is going to make an ounce of difference.

If possible, you must lower the outside ground level 150mm below the FFL. Given that this might not be possible then could you install a "French" drain (research on here) at the high GL elevations?

Layered slate might originally have been laid without mortar.

If you pull your base units and appliances from the wall(s) in question then take pics of the internal and external situations and post them on here.

Hacking off all plaster to window sill height and rendering 6:1:1 with sand and lime and cement will give perhaps a few years respite.

Do you have solid floors?

 

[GarethEdwards101]

A new concrete floor was put in 12 years ago with a polythene membrane. the problem I'm facing regarding the outside ground, is that the ground narrows to about 12 inches at the rear corner of the house this is part of a boundary wall/elevated road. The house is situated on a hill with a elevated road running by the rear, roughly 12 foot above the houses ground level.

Thank you all for your advice so far

 

[RHGrenedier]

Are you saying that you can't access the exterior of the wall, at all?

 

[GarethEdwards101]

No, the area at the back of the house tapers to a very narrow point which is only 12 inches at the narrowest point from the rear wall to the boundary wall. This is roughy at the rear corner of the house, most of the area is easily accessible and has been concreted in the past.

Would you say I have been ill informed regarding having an injected cream or liquid DPC into a 2 foot think slate wall house?

 

[AronSearle]

Would you say I have been ill informed regarding having an injected cream or liquid DPC into a 2 foot think slate wall house?

And here was me thinking these cowboys only existed in the UK.

 

[ree]

The concrete at the rear appears to be serving no purpose, it might even be ponding water - the damp is penetrating below surface level. The concrete will only obstruct the installation of a French drain.

I made a few suggestions above - do you have any replies?

 

[GarethEdwards101]

The house is in Wales, so I am unable to get any photos for the time being. A company came out to look at the problem and stated that the cream injection DPC would fix the damp issue. The walls are of slate and mortar fabrication the slate being the large quarried type.
Since I am not in the house building/maintenance business I am looking for as much info so I can try and make a well balanced decision on how to go forward. My gut says that trying to inject slate with a DPC is pointless as slate is damn hard and not known for its porous quantities, and after reading these posts the problem lies with the surrounding ground and it's the ground issue that needs to be addressed not the wall.


The concrete at the reader was put down to have a level stable area.

 

[ree]

An expensive possibility is to tank, drain and pump the damp walls, just like a basement refurbishment tanking.

Do you intend to keep or sell the cottage?

If the area in N. Wales is Tainygrsiau or Ffestiniog then dynamite would be required for blasting out the underlying rock - at least, thats how the slate miners did their DIY.

I would suggest consulting with some old neighbours they will know all about dry and wet houses. N. Wales is the equivalent of living in the Titanic for the unwary.

 

[GarethEdwards101]

Between Ffestiniog and Porthmadog, unfortunately explosives would not be very neighbor friendly.