The Schrijver damp proofing system

Schrijver damp proofing - avoid like the plague

This system is yet another of the completely useless damp proofing cons which defaces your building.  These horrible people will come and drill holes in the wall, and cement silly bricks into it which they claim will let damp evaporate. They claim on their website that the system is 'researched' - yet you'll find NO independent research.

Amazing that they always target homes which are cement rendered, and usually occupied by old people who are easily conned. Often they are in little chocolate box thatched cottages.  This is the same thing as the Holland Damp Proofing system which collapsed after defrauding thousands of people.  We ran a concerted campaign to rid the world of the Holland system - and succeeded.

Don't even consider one of these stupid systems.  If you have a 'damp' problem - the issue is likely to be the very cement render they drill through.  If all they did was to take the render off instead of inserting silly bricks, the house would dry out.  A lot cheaper, and better for the house!

Schrijver Damp Proofing, Schrijver Damp Control, The Dutch Damp Proof System - are all names they use. 

This is a house they have destroyed in a lovely little Shropshire village - doesnt it look just ridiculous - and horrible.  This place is SMOTHERED in cement render. The simple solution to the issues of moisture in this house are two fold - remove the render and either re-point in lime, or re-render in lime.  Internally, it needs better humidity controlled ventilation.  This work is illegal - it's criminal damage of a Listed Building. Interestingly, Shrijver complained to Google about the video and tried to claim it's not their product.  These criminals just try to muzzle anyone who dares to reveal their fraudulent con to the world. Didn't work, Mr Gerardus Bernardus Franciscus Maria Schrijver -and there's more revealing videos and evidence to come.  They have come up with another con - the 'Dry Brick' - we'll introduce that to the world shortly.  


Have a look at the independent newspaper articles about the con of the schriver system below:

The Telegraph on schrijver..

Q My husband and I live in a bungalow converted from a building first constructed in 1914. We have lived here since 1993, but now one wall in a room has become very damp and we want to know if the Schrijver System would help. Or should we get in a company that works in damp-proofing? JM, Greenwich

A The Schrijver System is advertised as a “clean, green way to a drier indoor climate”. It is based on the idea that holes in the outside brickwork, filled with plastic boxes containing pieces of concrete, will magically reduce the moisture content of the walls themselves, and reduce internal humidity levels to boot. I was first contacted by Frank Schrijver in 1997, when he asked me to help publicise his so-called “invention”. I asked him then to provide me with independent scientific evidence to support his theory and now, 13 years later, I am still waiting.

The Schrijver System is the latest in a line of “hole-in-the-wall” damp-proofing gadgets, dating back to the early 1900s. None have ever been independently shown to have any effect on the moisture content of walls or internal environments. Equally, I would advise against any other kind of damp-proofing outfit. These companies are adept at using electrical moisture meters to mis‑sell chemical-injection damp-proofing to unsuspecting clients. Your 1914 home will have been constructed with a built-in damp-proof course, and cannot therefore be suffering from the mythical “rising damp”.

If you have lived in your home for 17 years without problems, and one room has suddenly started to exhibit symptoms of dampness, then there must be a rational explanation – a blocked gutter, perhaps, or a plumbing leak.You need independent advice from someone who is not going to try to sell you a snake-oil cure. A chartered building surveyor might be able to diagnose the problem. Otherwise, independent dampness experts that I recommend are listed in my Sunday Telegraph book.

The Independent

This is an article published in the Independent - and is their Copyright.  The original article is here:

Property: Tubes that suck up your money, but not the damp

DOCTOR ON THE HOUSE; A discredited technique for keeping walls dry is still being flogged by the building trade
IN 1919, during the Great War peace conference, a member of the British military delegation noticed something interesting in the Palace of Versailles: a row of small circular vents along the bottom of a wall. After some inquiries the delegate - one General Brown - found that the vents concealed ceramic tubes set into the wall for damp proofing, a process that had been patented in 1908 by a Belgian, Monsieur Knapen.

General Brown introduced the Knapen tubes into Britain under licence, and apparently enjoyed some commercial success with British Knapen Ltd before selling up. Ceramic tubes continue to be made, marketed and installed in British homes.

The only trouble with a damp-proofing system which uses ceramic tubes is that it doesn't work.

At first sight, the idea of drilling holes in a wall to remove moisture might seem logical. After all, increasing the exposed surface area should assist evaporation, shouldn't it? But there was always supposed to be more to the tubes than that. The fine pores of the ceramic clay would actually draw dampness out of brick and stone. The angle at which the tubes were stuck in the wall would cause the moist air to flow away by gravity. It was even thought that the Dutch clay from which the tubes were made had special properties.

But any physicist will tell you that the system cannot work because the finer the pores, the greater the capillary action, or suction - and this makes a material hold on to its moisture, not dry out by evaporation. Any evaporation at the surface of the tubes would cause a build-up of dissolved salts, which would attract moisture from the air and actually make the wall damper. These suspicions were verified by experimental work published in Germany in the 1960s. Ceramic tubes do not make walls dryer, and in some cases they can make them wetter.

Even the damp-proofing industry trade body, the British Wood Preserving and Damp Proofing Association (BWPDA) has a code of good practice which advises against using ceramic tubes.

But nobody in the building game ever let a few facts fog the issue. The contents of foreign-language science journals do not find their way easily into the British press. So 30 years after they were shown to be worthless, ceramic tubes are still being marketed, and even described in construction textbooks as a proven way of keeping walls dry.

Watch out for anyone who tells you your home needs damp-proofing after using electrical moisture meters to diagnose rising damp. These give high readings on walls even when the actual moisture content is low, so that whatever the "damp-proofing" employed, it was probably unnecessary in the first place. Second, any damp-proofing contractor challenged over the efficacy of his installation will take a drilled sample from the wall and pronounce it dry - "proving" his damp proofing has worked.

Two lessons from this: anyone wishing to avoid unnecessary damp-proofing work should ask for the drilled sample test to be done first; and anyone thinking of having the ceramic tube system installed should think twice, or they could watch their money go straight down the tubes.

You can contact Jeff Howell at the 'Independent on Sunday' or e-mail:

Damp and Condensation
Latest News
Pete's on BBC Radio 4 now!

Pete recently did an interview on BBC Radio 4 - You and Yours - which investigated a case history of failed cavity wall insulation.

Read More
Guidance concerning Energy Efficiency in Historic Buildings

This is the English Heritage Guidance document that covers almost all the issues I cover in this site.

Read More
An Irish client and his magnificent restoration blog

Our client, John, wanted help with this restoration - it led to this great blog.

Read More
Rising damp is a myth, says former RICS chief

Stephen Boniface, former chairman of the construction arm of the Royal Institution of Chartered Surveyors (RICS ), has told the institute’s 40,000 members that ‘true...

Read More
It's Condensation Season!

The phone is running off the hook with calls about condensation. Find out how to solve your issues.

Read More
The Haynes Manual for Period Property

Ian Rock has written another of his great books.  This one is even better - We've helped Ian with this one and there's loads of photos of our guys doing timber frame work.  A great book, with lots of practical information you need if you have an old home.  Treat yourself and buy this - you won't regret it!

Website by twoclicks