BBA and Rising Damp

[fab44]

I was just thinking about that debate that everyone used to have on this forum about rising damp and it ocurred to me that if it doesn't exist how do the BBA test to see if products can work against it. In total there seem to be 34 BBA certificates for rising damp products (see links below).

http://www.bbacerts.co.uk/query.idq.../certs/&TemplateName=query&CiSort=FileName[a]

http://www.bbacerts.co.uk/query.idq.../certs/&TemplateName=query&CiSort=FileName[a]

Does anyone know how they do the test?

 

[Joe Malone]

You need to read the BBA's MOAT No 39, which is the Method of Assessment and Testing. They carry out all sorts of tests that cover safety, durability, habitability, maintenance, practicability and quality assurance. They basically build brick test pillars in plastic trays then after the walls have been injected they fill the trays with water and monitor whether the water rises in the wall. This is a very simplified answer but their MOAT is quite an in depth document which explains all the tests in detail.

 

[fab44]

They basically build brick test pillars in plastic trays then after the walls have been injected they fill the trays with water and monitor whether the water rises in the wall.

So rising damp must exist - otherwise they couldn't carry out the test.

 

[Shytalkz]

Oh no....

 

[Joe Malone]

I know, even I'm getting bored of this question now. Maybe Mods could send every member an e-mail telling them that, yes, rising damp does exist.

 

[chessspy]

Hi, Joe,
I don't think anyone said RD doesn't ever exist, just that nowadays it is very rare and most black fungal growth is caused by condensation.
In a house with double glazed windows and little or no unplanned ventilation (draughts) which is centrally heated, the air inside at say 20 degrees c will hold a lot of water, when it encounters a cold surface it cools down and sheds it's water onto the nearest surface, creating ideal conditions for fungal growth (there are billions of spores in the air)
These cooler areas are almost always on outside walls and they are often coolest near the ground/floor, hence the appearance of dampness at floor level.
Any test which is going to be effective should penetrate well into the substrate (brick) if it's just the plaster that's wet then its condensation.
Remember that often the person doing the testing will have a financial incentive to give a false positive.
I doubt if anyone will disagree with this summary, and I hope this can be the end of it.
Alan D.

 

[Joe Malone]

Hi Chess. Yes, but I'm sure it won't. If you look back at previous threads there are lots of people claiming that it doesn't exist. Hopefully we've laid that one to rest now.

 

[chessspy]

Hi, Joe,
Everyone is entitled to hold whatever views they wish. Right or wrong.
For example those who believe in God and those who believe in evolution cannot both be right, but for the most part, sensible people manage to get along with each other.
The problems arise when one group tries to impose their 'right' view on the other.
I have expressed my view and can think of no reason why I should ever comment on it again, as any new boys can read through the back threads and decide for themselves.
I personally do not give a tinkers curse either way.
Alan D.

 

[joe-90]

It all depends where people live. In some areas it doesn't seem to exist (chalky areas) in others (Trent Valley) it certainly does.

 

[kevintaylore]

They basically build brick test pillars in plastic trays

That's interesting. I'd always imagined that they built proper walls. Surely a pillar is going to have a much higher exposed surface area - therefore resulting in higher evaporation rates and distorting the results. Does it say how big the pillars are and how much damp is allowed to rise in order for the product to pass?

 

[Joe Malone]

My understanding is that they build the pillars with London stock bricks then fill the tray with distilled water and allow the wall to get wet through capillary action. They then remove the water, inject the walls then fill the trays with water again. Every month thereafter they take samples from the wall and test the moisture content using the gravimetric (oven drying) method. It's not how wet the wall is to start with that's important but whether or not the wall starts to dry out after injection. They plot a graph every month against the samples taken and look to achieve a graph profile that shows the wall is drying out.

 

[fab44]

I would have thought they used proper walls as well. I know that rising damp does exist as I have seen it many times. However I also think that it is not as common as some people think.

 

[davebelushi]

Hi, Joe,
Everyone is entitled to hold whatever views they wish. Right or wrong.
For example those who believe in God and those who believe in evolution cannot both be right, but for the most part, sensible people manage to get along with each other.
The problems arise when one group tries to impose their 'right' view on the other.
.

brilliant, comparing the belief that rising damp exists to believing in god.
just brilliant.
where's richard dawkins when you need him.

 

[Shytalkz]

brilliant, comparing the belief that rising damp exists to believing in god.
just brilliant.
where's richard dawkins when you need him.

Or Banal Sheds

 

[Joe Malone]

Yes, I believe there's a chapter in The God delusion on rising damp.