RISING DAMP

Experienced and professional rising damp repairs in Melbourne

Rising damp is caused when surrounding clays and soils are absorbed into the masonry components of a building’s structure by capillary action, and move upwards through the building. The level to which the damp will rise is determined by the efficiency of any original damp proof course, the volume of the water supply, evaporative conditions over the wall surface, and humidity.

The term rising damp is generally used when dampness appears above the floor or skirting board level of the property causing damage to brickwork, mortar joints, plaster, paintwork or wall coverings. This can, in most cases, be attributed to the lack of, or failure of, the building's damp proof course. 

Allow our professional rising damp specialists here at FG James Pty Ltd help repair the rising damp in your home today. Identification of the problem is the first step towards curing the problem.

The FG James System

Over 40 years ago, the English National Trust conceived the idea of pressure injecting a water proofing fluid into masonry to form a new damp proof course. The Trust had previously tried many other methods with only limited success. Since the early 1960's, the pressure injection system has become the most popular and successful method worldwide for establishing a new damp course. This is because of its ability to waterproof in a variety of materials including brick and natural stone and the many types of wall construction including random stone and rubble infill. The injection system is non-destructive and preserves structural integrity because it does not require disturbance of the brickwork or mortar lines.

The FG James system, in a typical application, consists of drilling a series of 10mm holes in a course of bricks. Each brick and all surrounding mortar lines are then saturated with a sealing fluid using a pressure variable pump and specialized injection lances. The new damp proof course is installed into the brickwork at floor line. The waterproofing fluid moves below the floor line from the reservoir of fluid within the bricks. Measurements to 100mm below floor line are commonly taken.

Technically speaking

Natural soluble mineral salts are commonly found in soil. When rising damp occurs, nitrates, chlorides and efflorescent salts migrate through the masonry in solution and accumulate on the wall surface as a white powder. These salts are hygroscopic and attract moisture from the atmosphere, particularly during periods of high humidity, and give the effect of persistent dampness and associated damp smells. Salt contaminated solid plaster will continue to attract atmospheric moisture even after the rising damp has been stopped. To prevent this secondary damp problem, the affected area of solid plaster must be removed. 

Advantages of choosing FG James:

  • Speedy, flexible and economical pressure injection method.
  • Salt and moisture contaminated plaster removed at the same time as installation of the damp proof course.
  • Replastering within 2 weeks of damp coursing. Eliminate the normal 4-6 month time lag, costly increases and further mess of stripping and replastering at a later date.
  • Repainting within a further 3-4 weeks.
  • Appointments made at a time to suit client
  • Full clean up, rubbish removal and skirting board replacement
  • 20 year guarantee

Hygroscopic Salts

Natural soluble mineral salts are commonly found in soil. When rising damp occurs, nitrates, chlorides and efflorescent salts migrate through the masonry in solution and accumulate on the wall surface as a white powder. 

These salts are hygroscopic and attract moisture from the atmosphere, particularly during periods of high humidity, and give the effect of persistent dampness and associated damp smells. 

Salt contaminated solid plaster will continue to attract atmospheric moisture even after the rising damp has been stopped. 

To prevent this secondary damp problem the affected area of solid plaster must be removed. The removal and replacement of plaster forms part of the F.G. James system. 

Contributing factors that cause rising damp are as followed:

  • No damp proof course provided at construction stage
  • Progressive deterioration of the original damp proof course
  • Replacement of timber floors with concrete
  • Building extensions using concrete floors abutting existing walls
  • New spilt level extension below original dampcourse
  • Bridging of the damp proof course from building rubble in cavity walls
  • Wall surface treatments that form a bridge over the damp proof course
  • Ineffective, or lack of, sub floor ventilation
  • Concrete paths or verandahs finished above and bridging the damp proof course
  • Incorrect concentration of a mixture in original damp proofing mortar
  • Garden beds built up above and bridging the damp proof course

Associated problems:

Many methods have been tried to hide or disguise rising damp over the years. These usually involve the placement of waterproofing materials or sealing compounds over the damp surface. This sometimes hides the damp temporarily, but in most cases causes a chimney effect that forces the moisture further up the wall. This does not solve the problem and creates greater expense in the permanent corrective treatment. 

Where rising damp is present, the moisture level is sufficient to propagate timber destroying fungi, which can attack skirting boards, architraves and window frames. Brickwork, stonework and mortar joints can be seriously affected by natural ground salts, which may lead to eventual structural problems.

rising-damp-bricks

For the most experienced and professional rising damp repairs in Melbourne, contact FG James Pty Ltd on 03 9885 9444 for your free quotation today!

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