Rising damp does not exist

[Joe Malone]

However, there is one error in all this thinking, irrespective of the presence or not of a vertical wall covering, the mortar alone represents one continuous and uninterrupted material from ground to ceiling, the horizontal inter-brick mortar is in contact with the vertical mortar and as it is the same material it has the same capillary size. Imagine your house, you can place your finger on the pointing at floor level and run all the way to your roof without ever once having to cross another material, take your finger off the mortar or anything of the kind. What is it that prevents the mortar alone wicking water up from the base of the wall and saturating the bricks?

Amphibian makes a very valid point here i think, and one that i've been wondering about myself. Can anyone answer it?

I consider myself an 'RD doubter' as well, so i'd be quite happy for someone to successfully explain it.



As well as that, there is this:

http://www.palgrave-journals.com/jba/journal/v6/n1/full/jba201013a.html

If you read it, it seems Mr Ralph Burkinshaw has successfully (and surprisingly easily ) demonstrated damp rising through brickwork.

How has he done this when Jeff Howell couldn't, and that guy on the BBC documentary (he wasn't Howell was he?) claimed he used lots of different mortar mixes - did it never occur to him to try a lime mix?

I'm a bit puzzled as to how the debate can rage for so long only to (seemingly) be easily solved by an experiment i could've, with a bit of effort, carried out myself!



Thanks to anyone who takes the time to respond, or is it time to silently retreat?

If you click the link...It's interesting. It SEEMS to prove that rising damp is real through a brick and mortar construction. It also SEEMS to prove that injection works to stop RD. I make no comment...as my head is spinning. I do note however that the guy is in 'the industry'....My Victorian house, circa 1890, has no foundations...just splayed out bricks at the base direct to the earth. This brickwork 'foot' contains 2, joint offset, layers of a material that resembles terracotta tiles, about 12mm thick. It certainly is not a slate dpc and it does not SEEM to restrict water movement...so I wonder what it's purpose was/is?. It's an interesting discussion this...tho I am driving my neighbour mad with these alternative thoughts as he is 'a believer'. I wonder where the OP has gone...not being sarcastic here, I enjoyed his analytical thinking and cross examination. He'd be a fine defense barrister I dare say.

Injection can work to stop rising damp, particularly the modern aqueous silane creams when injected directly into the mortar bed. We know that the major moisture pathway for rising damp is the mortar perps so there is no need to drill bricks anymore; this technique was always pretty pointless and damaging to the building fabric. The key issue here though is to understand that DPC injection, even if installed after a correct diagnosis, (and it rarely was) is only a management solution and the internal plastering was equally important because you were not giving the walls an opportunity to dry out, therefore the renovating plasters role was to dam in the damp and provide the appearance of a dry wall finish. Pragmatically sometimes you need a management solution rather than a cure but a cure can be affected on the vast majority of occasions without resorting to DPC injection.

 

[tony1851]

@J.M.,

An good read - thanks.

Your comment about the mortar perpends being the main transfer path is interesting. A moment's thought suggests that the mortar in the bed joints is always going to be more compact and dense than that in the perpends. This is because the bed joints are being continually compressed as the brickwork proceeds, while that in the perpends is never compressed and will inevitably be more porous.

 

[Joe Malone]

@J.M.,

An good read - thanks.

Your comment about the mortar perpends being the main transfer path is interesting. A moment's thought suggests that the mortar in the bed joints is always going to be more compact and dense than that in the perpends. This is because the bed joints are being continually compressed as the brickwork proceeds, while that in the perpends is never compressed and will inevitably be more porous.

Thanks Tony, you may have made an insightful point with regard to reduced porosity in the bed joints, as far as I know this has never been tested but my comments about the perps relate more to the fact that moisture can travel higher through the perps. I rewrote the definition for rising damp based on this principle. The main moisture transfer mechanism is diffusion and not capillary action. It was also previously thought that moisture moved up the wall through the masonry units rather than the mortar joints that separated them.