The existence of rising damp and the problems caused by it have been documented since antiquity. In the UK, various documented and professional publications have documented rising damp since the early Victorian times, going back almost 200 years.
The Roman Period
The first known written historical reference about rising damp goes back to ancient Rome. The Romans, being excellent engineers, that have built some masterpieces that lasted over 2000 years. Historic records show that they not only were aware of rising damp, but they also worked out efficient solutions in combating it.
"I shall next explain how the polished finish is to be accomplished in places that are damp, in such a way that it can last without defects. First, in apartments which are level with the ground, apply a rendering coat of mortar, mixed with burnt brick instead of sand, to a height of about three feet above the floor, and then lay on the stucco so that those portions of it may not be injured by the dampness."
Remnants of old Roman damp proof courses still exist today.
Historical References from the UK
From 1877 the use of damp proof courses became mandatory in the UK, however references in books and specialist publications go back as early as 1844. Here are some historical references from the UK describing the existence of rising damp, along with recommended solutions on how to overcome it.
Click on each publication to expand additional details.
The Builder was a journal of architecture published between 1843 and 1966. Issues from year 2 (1844) mention dampness rising from the ground due to capillary attraction. As a solution, to prevent the ascent of moisture up the walls, it recommends the use of slate inside the walls.
This professional textbook from 1851 is a practical manual written for architectural students, engineers, contractors and builders.
Dedicating a whole chapter to dampness, including to the prevention of rising damp, stressing the importance of separating the foundations from the rest of the wall with a damp proof course, to stop the upward migration of dampness.
"... to intercept entirely all communication between the foundation below and the walls above, no damp, as far as we have observed, can possibly find its way upward; and however damp the work below the asphalte (DPC) may become, that above will remain perfectly dry and unaffected."
French architects, independently, came to the same conclusion. Even if the footing of a building is always underwater (e.g. in a lake), using less than half an inch thick asphalt DPC keeps the walls completely dry.
This paper read on 12 Jan 1863 at the General Meeting of the RIBA, discusses the sanitary aspects of rising damp in old buildings, and various damp proof course options as a natural remedy to the problem - about 20 years ahead of global UK sanitary reforms,
"The great evils, in a sanitary point of view, are doubtless caused by damp rising up the walls by capillary attraction. (...) Our remedies for this have generally been a layer of asphalte throughout the thickness of the walls, "sheets of lead", a course of slates bedded in cement, and sometimes compounds of gas-tar, pitch, sand etc."
A new damp proof course is also presented to the attending architects - a layer of perforated bricks, laid as a row of ordinary bricks, to prevent the rise of moisture, while also improving underfloor ventilation.
Some of the architects' comments on this damp proof course technology included:
- Many new inventions are adopted with difficulty, including the idea of damp proof courses.
- Some concerns about their additional cost. Damp proof courses have often been skipped to save on material and labor costs.
- They should be better tested, although in buildings used (e.g. the great Artillery barracks at Colchester) they were very efficient.
- Their aesthetic look is a positive.
- Architects were in agreement that damp proof courses were the best method of keeping damp down.
A report of the British Medical Journal dating 20 Dec 1873 discusses various sanitary aspects of rising dampness in houses, hospitals and public institutions.
Various damp proof course technologies used by architects are mentioned in the paper, including double course slates, Welsh slate bedded in cement, sheets of lead, hot asphalt DPCs, glazed bricks and vitrified stone-ware tiles.
The paper also advises the retrofitting of a damp proof course into old buildings, which turned uninhabitable buildings into perfectly healthy ones.
This 3-volume publication from 1876 was the official syllabus of a three-part advanced building construction course. A whole chapter is dedicated to the problem of dampness and how to efficiently overcome it, including rising damp, penetrating damp and falling damp from the roof or gutters.
Various damp proof course technologies are also discussed, making reference to the fact that slate DPCs embedded in cement are liable to crack and thus fail.
Glazed pottery slab damp proof course built into the wall:
Lastly, according to an official report from the 1867 Paris Exhibition, some interesting technical facts from the book on how much water saturated brickwork can hold:
- In England, common bricks can absorb as much as a pint or pound of water
- An ordinary cottage consisting of 12,000 bricks, can hold about 6.5 tons of water when saturated
- Porous sandstone fit for building purposes may contain about half a gallon of water per cubic foot. (about 80 liters / m³)
Realizing the effect of damp walls onto the health and well-being of inhabitants, between the 1870s - 1890s a number of health bills have been passed throughout UK, all of them recommending damp proof courses as a means to combat capillary rising damp.
"We must now turn our attention to the walls, which is equally necessary to protect from rising damp. If you plant a brick or stone wall o ground which is capable of retaining moisture, it will inevitably happen that unless you take means to stop its progress, the moisture will climb up the walls in obedience to the law of capillary attraction."
Solution to the problem is a vitrified (glass-like) layer of bricks or two layers of slate.
The book also provides technical advice with drawings, presenting the wrong way of laying a slate damp proof course">, if gaps are left between them.
Clause 96 of the The London Public Health Act from 1891 stipulates the use of damp proof courses for underground rooms: "Any underground room (...) shall not be let or occupied unless (...) every wall of the room is constructed with a proper damp proof course">."
Modern Scientific Research and Studies
Modern research has helped us clarify many aspects of the mechanisms underlying rising damp. Research papers from all over the world confirm its existence, highlighting some of the irreversible damages it can create to old buildings.
Click on each publication to expand additional details.
Old-House Journal is a USA magazine devoted to restoring and preserving old houses. Since its establishment in 1973, the magazine has published many articles on rising damp, the 1994 May-June edition being one of the more comprehensive ones, covering its mechanism, its manifestations and most common remedies to overcome it.
The Journal says:
"Rising damp is most common in low-lying, high-watertable coastal regions such as Charleston, South Carolina, Galveston, Texas and New Orleans - the proverbial land of rising damp. (...)
The symptoms caused by rising damp have been recognized for centuries, and its general action has been understood for close to 150 years. (...) In the "Architecture of Country Houses" (1850) A. J. Downing how foundation walls laid with lime mortar absorb moisture from the soil, particularly damp soil."
Rising damp: capillary rise dynamics in walls, 2007
This UK research paper published by the Royal Society in 2007 not only acknowledges the existence of rising damp, saying that it is an important cause of wetness in buildings...
...but also discusses in detail the various factors influencing rising damp. The paper provides the necessary formulas for calculating various rising damp parameters (rising damp height, quantity of water inside the walls etc.) for walls of different thickness.
An operative protocol for reliable measurements of moisture in porous materials of ancient buildings, 2006
This scientific paper published by the University of Bologna, Italy in 2005, states at the very beginning that capillary rising damp (along with other types of moisture) is one of the main problems in old buildings.
The paper discusses the various moisture measurement methods, while also presenting a methodology on how to easily recreate rising damp under laboratory conditions.
Treatment of rising damp in historical buildings
This paper is part of a series of research papers on rising damp published by a research team at the University of Porto, who have analyzed in detail the mechanics of rising damp, the effect of various wall structures and finishes, and they proposed and analyzed in lab and in-situ a new wall-base ventilation system, as a means to reduce the effects of rising damp.
"Humidity is one of the main causes of decay in buildings, particularly rising damp. (...)
In historical buildings, rising damp is particularly difficult to treat due to the thickness and heterogeneity of the walls.
Traditional methods have proved somewhat ineffective. There is therefore a need to study new systems."
Rising damp has also been reproduced and studied under lab conditions.
Rising moisture, salts and electrokinetic effects in ancient masonries: from laboratory testing to on-site monitoring, 2013
This research paper on rising damp from 2013 studies rising damp and its effects under both laboratory conditions and in real buildings. The paper acknowledges that rising damp is a complex phenomenon influenced by a multitude of factors, which leads to the decay of both ancient and modern building materials.
Results of rising damp recreated in the laboratory after 6 months are also presented.
Building Dehydration - From Basics to Practical Applications, 2017
This 270-page Austrian technical reference book discusses in great detail every aspect of moisture movement and building Physics.
It describes in detail the development of rising damp through its various phases; one interim phase being interstitial condensation. The book makes a clear distinction between rising damp and condensation, which are two different phenomena.
The stages of dehydration and various mechanisms that contribute to the dehydration of the building fabric are also presented in a logical and structured way.
Rising damp in two traditional clay-brick masonry walls and influence on heat transfer performance, 2019
his 2019 research paper from China studied the effect of rising damp on the heat loss of the building and they found that "the presence of capillary water has a direct impact on the heat transfer coefficient of the wall." - the damper the walls the more heat loss occurs.