New Damp Proof Course

[anobium]

Oh, the internal floor is 7 inches above the outside ground level.

In that case you've wasted the money you spent on the DPC company, and exposed them as charlatans.

I would sue my surveyor if I were in your position.

OK I know I'm going to regret this , but Softus on what basis have you decided that the dpc company are charlatans.
If anybody is a charlatan it is you for giving advice without knowing all the facts.
Let round 2 begin!

 

[Softus]

Very well, anobium, since you've declared my opinion to be of no value to you, I see no reason to answer your question.

For the record, and as I've observed before, I think you have a potentially valuable contribution to make on the subject, but you manage to wrap it up with groundless personal accusations and flippant remarks such that the debate never progresses.

 

[anobium]

On the contrary Softus , I value your opinions greatly and I genuinely look forward to reading them.
Its just that on this ocassion, you most out of character, accuse somebody of being a charlatan without knowing all the facts.
Now if you know something about this particular situation that I do not know, please tell me and then I will withdraw my remark.

 

[Softus]

ok anobium, fair play.

I assure you that nothing was out of character; my reasoning was thus:

1. A property had a damp problem.
2. A DPC injection company was engaged.
3. Seemingly, instead of noticing the (alleged) 7" level difference, and either advising on or rectifying it, they proceeded to inject the wall, which we all know would never have solved the damp problem.
4. If they knew that injecting would not solve the problem, then they are both crooks and charlatans.
5. If they didn't know that injecting would not solve the problem, then they are incompetent, and are masquerading as experts in the field, therefore they are charlatans.

To me, that was obvious, and I hereby apologise for assuming that it would also be obvious to everyone else.

 

[noseall]

Oh, the internal floor is 7 inches above the outside ground level.

don't mean to be a party pooper, but this is fairly normal.

 

[Softus]

Oh, the internal floor is 7 inches above the outside ground level.

don't mean to be a party pooper, but this is fairly normal.

Yes - it is normal, and I am a pratt, having misread the polarity of the difference.

Apologies to anobium and to everyone to whom my post caused confusion or distraction.

 

[hotrod]

How can you tell the difference between the two?

Penetrating damp comes from an identifiable problem, rising damp does not exist.

Rubbish.

You seem very confident of the existence of rising damp in brickwork.

Yes. That would be because it does exist.

Would you mind answering a question about it: if it happens so easily and frequently, why have only two people on this web site, to my knowledge, ever, out of all those who've argued, written and read about the subject, been able to describe a real-life example of rising damp that they've seen with their own eyes?

I did not say it happened so easily and frequently - they are your words - not mine. In modern day house construction with the appropriate use of dpcs rising damp is highly unlikely.Yes I have seen 'real' world examples of rising damp with my own eyes, in Victorian properties built without any dpcs. I also appreciate that many damp problems are often mistakenly attributed to rising damp through either ignorance or cowboys out to make a fast buck.

Before you ask I have no commercial interest in dpcs or damp proof companies. I am posting here as the statement that rising damp does not exist is misleading and unhelpful to people who may be led to believe this is true. It is not. The process of rising damp requires a number of factors which is explained below. I hope you find it useful.

The following is an excerpt of how rising damp works and although not published or subject to copyright I acknowledge the source as Andrew K Platten, BSc(Hons), PhD, FCIOB

The Process of Rising Damp.
The nature of porous materials provides a constant potential of capillary attraction or suction upon any moisture close to the building's environment. Thus porous materials readily absorb moisture. The degree of suction will become greater in the presence of fine pores whilst coarse pores of greater diameter exhibit a lower level of suction. Moisture absorption is additionally affected by the ability of the pore structure to transfer or conduct moisture. The smaller the diameter of pores present and the more complex the pore structure formed the greater the resistance to moisture transfer will become. Thus the process of moisture absorption is the product of two main factors, these are:

(i). Capillary attraction or suction.
(ii). The rate of transfer or conduction of moisture through the pore system.

In respect to the material types discussed the materials with finer pore systems such as the Class A or B Engineering bricks, dense Sandstones or certain high quality Terracotta products for example would exhibit extremely slow rates of moisture absorption. The coarser pored materials such as Facing quality brickwork, limestone and clay block would exhibit higher rates of water absorption. In consideration of the typical forms of concrete block commonly used in construction despite the coarse pore structure little water absorption would be experienced since the initial suction exerted upon moisture would be almost negligible in comparison to one of the finer pored materials although once moisture had entered the block the conduction of moisture would be relatively free. Over an appropriate period of time however it is possible for any porous material subject to a constant supply of water to become completely saturated. This is dependent upon the assumption that moisture is not removed from the material by evaporation or drainage of some kind. By the action of capillary suction it is in fact possible for a infinite height of material to become saturated with water to a height of several metres. This process of moisture absorption is referred to as capillary rise of moisture or rising damp.

Thus in the case of the construction use of any porous building material it is likely that moisture will be drawn from the ground and into the building fabric.

Capillary rise is dependent upon several factors, these can be identified as the following:

(a). A limitation upon the supply of moisture from the soil where usually the amount of water is dependent upon seasonal rainfall which produces periodic variation in the height of the water table that may lie below a building. Thus there is likely to be a plentiful supply of water during the winter months whilst it will be scarce in dry summer periods.
(b). The process of evaporation from the exposed faces of brickwork will remove moisture from the material and thus influence the overall moisture rise process, where:
1 If the rate of loss of moisture by evaporation is such that is greater than the rate of capillary rise then the rise of moisture will be reduced and thus the material will begin to dry out.
2. If the material exhibits little resistance to moisture rise then the evaporative process will simply draw off moisture from the wall where upon it will be replaced by the up flow of moisture entering the material.
3. If the rate of evaporation is such that it is less than the up flow of moisture the structure will gradually become saturated. The rate of evaporation itself is dependent upon three environmental factors which may be identified as the following:
1. Temperature.
2. Humidity.
3. The rate of air flow over the drying surface i.e. the ventilation rate.
4. Finally the rate of capillary rise is dependent upon time, where buildings subject to long periods of moisture rise are likely to exhibit particularly severe examples of moisture penetration and associated degradation problems. Where in terms of pore structure the period "long" infers a period of 40 years or more a period suitable to infer that any building built before the Second World War subject to rising damp will be subject to moisture related degradation. New building work may not exhibit such problems of the same degree simply because there has not been enough time for moisture to penetrate high enough to affect the building fabric but nevertheless certain forms of deterioration are possible and the problem should not be overlooked

The process of capillary rise or rising damp in masonry walls is thus dependent upon 4 factors: the rate of capillary rise through the structure, the supply of water to that structure from the ground the rate of evaporation from the wall and time.

When each of the 4 factors are taken into account it is usual to find brickwork and similar porous building materials subjects to unrestricted capillary rise to be saturated with water to a height of 1 metre above ground level. Additional information at this point may also be obtained by reference to BRE Digest 245 "Rising damp in walls: diagnosis and treatment." (1981).

 

[Softus]

You seem very confident of the existence of rising damp in brickwork.

Yes. That would be because it does exist.

By that token I'm equally confident, because it doesn't exist.

I did not say it happened so easily and frequently - they are your words - not mine.

No - they are the words and/or sentiments of all those people, of whom you're just one, who have insisted that rising damp exists, all but of whom are unable to claim to have seen one shred of evidence to support their faith.

Yes I have seen 'real' world examples of rising damp with my own eyes, in Victorian properties built without any dpcs.

Is there any one of those whose address you can divulge without encroaching on anyone's privacy?

I also appreciate that many damp problems are often mistakenly attributed to rising damp through either ignorance or cowboys out to make a fast buck.

I agree.

Before you ask I have no commercial interest in dpcs or damp proof companies. I am posting here as the statement that rising damp does not exist is misleading and unhelpful to people who may be led to believe this is true. It is not.

In brickwork, it is true. Nevertheless I've carefully read what you've posted, and with great interest.

The following is an excerpt of how rising damp works and although not published or subject to copyright I acknowledge the source as Andrew K Platten, BSc(Hons), PhD, FCIOB

The Process of Rising Damp.
The nature of porous materials provides a constant potential of capillary attraction or suction upon any moisture close to the building's environment. Thus porous materials readily absorb moisture. The degree of suction will become greater in the presence of fine pores whilst coarse pores of greater diameter exhibit a lower level of suction.

This is far from the universal truth that it purports to be. The 'suction' (which is a quaint but nonetheless understable word) is not simply derived from pore diameter, but depends on the nature of the liquid being absorbed, it also being influenced by surface tension and temperature.

[more technical stuff]

The rest of what you've posted completes the demonstration of a complete lack of consideration for mortar in brickwork. This is an important point, because I've always been careful to say that RD doesn't occur in brickwork, i.e. I've never claimed that it doesn't occur in a brick.
_______

The article you've quoted gives the impression of being scientifically researched and composed, but it isn't. It's just someone's view, as betrayed by the frequent (my word) use of "likely" without any numeric substantiation of the precise likelihood.

IMHO the article successfully discredits itself, without any help from me, thanks to the following self-contradictory (and, frankly, beserk) statement:

By the action of capillary suction it is in fact possible for a infinite height of material to become saturated with water to a height of several metres.

Infinite? Really? What's next - perpetual motion?

 

[hotrod]

Softus,

as pointed out in my previous post the process of rising damp requires a number of factors. True, the article does not address the flow of water through mortar and the use of the word 'infinite' is not very helpful - although I am sure the author was looking at this from a purely theoretical perspective.

It was a document I had readily to hand at the time which was easily accessible electronically and could be posted without breaking any copyright. As listed earlier they are a number of good resources available with regard to rising damp.

Anyway we digress, you have the right to discredit the theory of Rising Damp if you so wish, just as I have the right to accept that it does exist. I am not here for an argument.

 

[Softus]

As listed earlier they are a number of good resources available with regard to rising damp.

I predict that they will all share the same theoretical and/or practical flaws.

Anyway we digress, you have the right to discredit the theory of Rising Damp if you so wish, just as I have the right to accept that it does exist. I am not here for an argument.

I don't wish to appear argumentative for the sake of it - I have the same dim view of cowboys as you. What motivates my quest for a real-life example of RD is that I believe that the myth of it existing allows both cowboys and corrupt surveyors to continue in business.

If mortgage lenders and the general public were to wake up to the fact that it doesn't occur, then (a) the money wasted on injection would be spent on actually fixing the problem, and (b) the money spent when there is NO problem would be saved.

This is all in the interests of the common good - we're spending a fortune on, for example, pathetic attempts to save the planet after the damage has been done (and while most of the world is still doing it), instead of alleviating poverty where it exists.

I'm gonna 'phone Bob Geldof - Make The Myth of Rising Damp History is the new cause I suspect he's been looking for.

 

[ianblue]

How can you tell the difference between the two?

Penetrating damp comes from an identifiable problem, rising damp does not exist.

Rubbish. Suggest you do some reading into capillary action of moisture through brickwork.[/quote




I am sceptical about rising damp. Why would it occur in some buildings and not in others.

I own two Victorian terraces with NO dampness in the plaster just above the skirting boards ( Solid 9" brick wall with plaster applied directly to the bricks. 2 courses above ground level.