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Agrément Board Certification

This specification is covered by a current Agrément Certificate, a copy of which is available on request.

Rising Dampness

This is the vertical rise of moisture through walls.  The water originates from the ground and passes up through the porous masonry, which acts like a wick.


To prevent or substantially reduce the capillary rise of water in the walls above the level at which the system is installed, thereby to prevent the appearance of such moisture on the internal surface of the wall.


A specially formulated dry mix of cement, quartz and reactive chemicals which when mixed with water, and inserted as described will create a chemical damp-proof course.  The product is particularly useful in random stone wall constructions.  The chemicals released react and form a crystalline growth which penetrates and blocks the capillaries, pores and fine cracks in mortar joints.

It is a solvent free product, ecologically safe and non-hazardous.


  1. Drill 19mm or 22mm holes at the intended damp-proof course level at a downward angle of 30 degrees to a depth of approximately 4/5ths  of the wall thickness.  These holes should be drilled at 230mm centres.  This should be repeated on the opposite wall surface ensuring that the holes are staggered giving overall maximum centres of 115mm.  When drilling from one side the holes should be drilled at 115mm centres.
  2. Following drilling, the holes should be flushed out with water to remove bore dust and to ensure that the drilled holes are thoroughly wetted before insertion of mortar.  Do not apply mortar to a dry wall.
  3. Mix the mortar in the proportion of 3 parts water to 5 parts mortar by volume using cold water adding powder to water.  Mix until a smooth cream consistency is achieved.  Immediately fill the caulking gun with the mixed mortar and insert the nozzle of the caulking gun to the depth of the hole, the trigger action of the gun will gradually push the nozzle out ensuring that no air gaps are left and that the hole is filled to its full depth.
  4. Make good any drilled holes on exposed surfaces to match, as far as is practical, the surrounding material but EXCLUDING the redecoration of the surface.
  5. The replacement or re-fitting of skirting boards and other fixtures and fittings is NOT included in the contract, unless specifically agreed in writing beforehand.  If skirting boards have been removed, it must be recognised that the boards may not be fit for re-use.

We reserve the right to depart from the provisions of this Specification in such respects as may be found necessary during the course of the work.


This system is subject to a ten-year guarantee on final completion of the contract in accordance with our standard terms and conditions.

Important Notes

1.  Breakable Items

Drilling may necessitate the use of percussion drills, causing slight vibration of the wall.  The client should remove any items of value from walls, window cills, shelves, or other areas, which may become subject to vibration.

2.  Party Walls

Where a party wall is treated, the cream emulsion may become visible in the neighbouring premises.  Drilling may cause slight vibration of the wall and breakable items should be removed from contact with it.  It is EXCLUSIVELY the client’s responsibility to obtain their neighbour's agreement, in line with the Party Wall Act before work proceeds. In view of these responsibilities we can accept no liability for damage in the neighbouring premises arising from these factors.

3.  Damage To Plants

So far as is practical, we will take steps to minimise damage to plants growing on or near the walls to be treated, but we cannot accept responsibility for consequent loss or damage to such plants.

4.  Cavity Wall Insulation

The carrier within the injection mortar may dissolve or otherwise damage polystyrene foam or other plastic insulation materials inserted into cavity walls.  We cannot accept responsibility for determining whether such insulants are present in cavity walls before recommending a damp-proofing system, or for subsequent damage to them.

5.  Drying Period

The installation of a damp-proof course serves one vital purpose only, to prevent or substantially reduce the future further capillary movement of water from the soil into the wall.  It does not itself dry the wall.  The wall must therefore be given time to dry out by the normal process of evaporation.  This drying period will depend on a variety of factors, including the wetness and thickness of the wall, the internal humidity, the porosity of the walling material and its internal and external renderings, the decorations, local climate and heating and ventilation arrangements.  A guideline figure based upon one months drying time per inch of total wall thickness will provide an indication of the period required before the wall may be expected to be dry.

6.  Lightweight Plaster

Lightweight, gypsum plasters should not be used on walls where a chemical damp-proof course has been installed. Please refer to our Re- plastering Specification.

7.  Future Bridging of the System

To maintain the effectiveness of the system the owner or occupier of the premises must ensure that the system is not bridged by the raising of flower beds, paths or drives etc., against the treated walls, or by the construction of new solid floors or other alterations or additions to the building.

8.  What are the Benefits?

Our findings are based upon visual or instrumental evidence as recorded in your report.  Regarding damp problems, unless it can be specifically diagnosed as condensatory, we have presumed that “damp” readings are due to the lack of a damp-proof barrier.  This is not intended to infer that any previous works carried out by others is at fault.  All initial checks for damp related problems are conducted with the use of a simple pin type moisture meter.  We do not, unless otherwise requested in writing, carry out damp surveys using carbide meters which require samples to be taken physically from the brickwork by drilling.

Injection Mortar Damp-Proofing System

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