update- rising damp

[ukstations]

So a few weeks ago I posted lots of pics here of my property where I had
torn down the interior plaster render, much of which had been put there after
previous damp proof re-rendering.

Anyway, for anyone interested, I have now removed some joists and discovered that
all of the SOIL PLATES have rotted away to a large degree and so have decided to replace ALL
soil plates on the ground floor throughout the house.

While undertaking the above, I also discovered that whomever last maintained the brick airvents
actually removed several bricks in strange places in the foundation to allow for air holes internally way below
exterior ground level despite the brick vent being located 4 to 5 bricks high externally. I want to state that this solution was poorly executed as the greatest amount of rot and damp have been found around these holes. I have since decided to block off these vents and instead, put floor registers in whatever new floor I decide to lay. I hope this will work to allow for some underfloor airflow.
Has anyone else done this?

Separately, I suffer from rising damp on internal walls. I have discovered that the entire concrete base under the joists at ground floor level is always damp. I am not sure what I should do about this but I am tempted to
ignore and just ensure that all joist ends are protected for the future and that my decorating account for the fact that the walls will be forever damp up to about 2 to 3 feet off floor level internally.

ps. I bought the haynes manual to victorian homes and it is just PERFECT!!!

Regards
C

 

[MdB]

The trick with ventilation is to have it from one side of the house to the other where possible so the wind can blow air through under the floor boards. Having damp soil or even a puddle under the house is not too unusual (I believe - I am not an expert) but you don't want any wood in contact with it.

Damp two to three foot up the walls suggests that there is some sort of problem (like high outside ground levels). My walls are held together with mud and I only have damp in the bottom 50mm or so as the walls can breathe easily now the cement has been removed for a year or so. I did have damp to a couple of meters up the wall when the cement was still on the insides. The ground water table can be 300mm or so below the surface at times so if anyone is going to get rising damp, we are and we don't (beyond a very small amount). The damp we did get was probably due to penetrating damp which couldn't easily escape (the walls are very porous) or condensation. It has hopefully gone for good now though.

 

[Flyfisher]

My current bedtime reading is 'The Rising Damp Myth' (sad, perhaps, but true). One interesting snippet is that, apparently, unless the ground is absolutely saturated with water it will actually act to draw water out of anything sitting on it. Of course, saturated ground is not unheard of, and the author makes reference to instances where leaking water mains have caused damp problems but, in general, the best advice seems to be to investigate all other possibilities before concluding 'rising damp' is the culprit.

A fascinating book, particularly the history of the 'phenomenon'. http://www.askjeff.co.uk/books.php for more details (no connection).