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"Preserving the past for our future"
Undertaken in conjunction with the installation of a new damp proof course, the removal of the old contaminated wallplaster and its replacement with a new waterproof rendering system form the complete damp proofing package.
Ground water is contaminated with salts, sulphates, chlorides, nitrates etc. rising dampness transmits these salts up into the masonry and subsequently through to the internal wallplaster.
These salts are hygroscopic, i.e. they can absorb moisture from the surrounding environment. The greater the amount of salts present the higher the absorption factor, especially under humid conditions.
Even though the rising dampness may have been eradicated by the installation of a new damp proof course, hygroscopic salts will continue to cause the internal wallplaster to remain damp, and the ongoing contamination of the decorative surface.
Remedial replastering to our Specification will ensure that the passage of remedial moisture and hygroscopic salts passing from the masonry to the new plaster is prevented.
One function of the new plaster is to retard the hygroscopic salts introduced into the wall structure through rising dampness, and to prevent them from migrating through the new plaster to its surface.
When the new plaster has dried out only a vapour permeable emulsion paint should be applied. Final redecoration should be delayed in line with our specification.
It should be noted that under normal conditions a wall dries out at a rate of approximately one month for each one inch (25mm) of thickness. A dry wall is one which has settled to its normal water content, depending on the nature of the walling material, and relative to the climate to which it is exposed.
For more detailed information please see our Re-plastering Specification, attached to your survey report.