Silicone DPC Injection Fluid

Technical Data Sheet

1.   DESCRIPTION

Antel Silicone D P C Injection Fluid  is a solution of a silicone resin in white spirit.  The solution is manufactured by a controlled batch blending process.  Regular quality control checks are carried out on the final product to maintain the highest quality damproofing fluid.

2.   USES

The process involves the saturation of a selected course of brickwork, or an equivalent area of block work or stone, with this fluid, by pressure injection and the subsequent replastering.  Please refer to Antel Rendermix and Replastering Specification.

3.   PACKAGING  

25 litre plastic containers.

4.   STORAGE/USAGE

4.5 litres of fluid are normally used for the treatment of rubble core in 1 metre of a 450 mm wall (increase pro rata for walls of greater thickness)

Store in cool dry conditions in original containers.  Protect from freezing.  Keep out of reach of children.  The solution is flammable with a flashpoint of 38°C to 39°C.  Keep away from naked flames.

5.   DURABILITY

Evidence exists that silicones used to waterproof walls against rain penetration are still effective after 12 years.

In such situations the silicone is applied to the surface of the wall, but a damproof course application saturates the wall in depth.  Provided there is no unusual ground water or other contaminant and provided there are no highly alkaline mortars present (as in new repair work) it is envisaged that the process will remain effective as a rising damp barrier for a period in excess of 20 years.

6.   HEALTH & SAFETY

The silicone solution gives off flammable vapour and it is therefore essential to ensure that no open fires are lit or other naked flames are present during and up to two days after injection.  Full ventilation must be provided during this time to avoid the accumulation of pockets of flammable vapour.

Precautions are necessary in handling and injection, to avoid bodily contact due to splashing, spillage or leakage.  The normal precautions (use of goggles/visor, gloves, protective clothing and the prompt removal of contaminated clothing) should be observed with particular rigour.  Should the fluid come into contact with the skin it must be washed off promptly.  If it comes into contact with the eyes they should be flushed with cold water for ten minutes and medical attention should be sought. If ingested seek medical attention immediately.

To protect third parties from contact with the fluid, the working area must be tightly screened off during treatment from the public highway (e.g. terraced houses abutting the pavement).

7.   INSTALLATION

7.1 Installation is carried out in accordance with the manufacturers instruction.

7.2 The course to be injected is chosen so that the position of the horizontal damproof course complies, as far as is practicable with BS Code of Practice 102:1973 (Protection of buildings against water from the ground)

The damproof course must be at least 150 mm above ground level and in the case of suspended timber floors must be positioned below the timber joists and/or wall plate.  Internal walls on solid floors are injected as close to the floor as possible. Complementary vertical damproof courses are positioned, where necessary, to isolate treated walls from the effects of rising damp in adjoining walls as, for example, in semidetached or terraced properties or where they are abutting garden walls.

7.3 Internal plastering affected by hygroscopic salts is removed from the area to be treated to a height of 300 mm above the maximum level of the rising damp.  Internal skirting, flooring etc are also removed, as necessary, to expose the area for treatment.  Externally, the proposed damproof course line is exposed by removing any facing material.

7.4 In brickwork 10 mm or 13 mm holes are drilled to predetermined depths along the selected course.  Two holes are drilled in each stretcher and one in each header at an average spacing of approximately 120 mm and maximum spacing of 150 mm.  If a brick course proves too dense to allow adequate penetration of fluid, drilling may be carried out in the two related horizontal and connecting vertical mortar courses, the holes not being more than 76 mm apart. Walls 115 mm thick are injected from one side only. Solid walls of greater thickness are normally injected from both sides, but if access is restricted, can be drilled and injected from one side by a series of injections at increasing depths at increments of not more than 100 - 120 mm.  Cavity walls are normally treated from both sides, but if the thickness of the individual leaves permits it, injection may be carried out from one side, at increasing depths.

7.5 In solid or cavity walls of conventional construction in block work or stone, the drilling and injection procedure is adjusted to accommodate variations in density, porosity and structure, but in each case the procedure chosen ensures a continuity of treatment.

7.6 The silicone solution is injected at normal pressure of  700 kPa.  Nozzles fitted with pressure tight seals are inserted into the drilled holes and injection is continued until complete saturation is achieved and the fluid begins to exude from the substrate.   The nozzles are removed and subsequent holes are similarly injected.

7.7 In flint walls, holes are drilled into the mortar joint, either horizontally or at an angle, to the mid point of the wall, at 75 mm intervals.  Injection is carried out at 400 kPa until complete saturation is achieved, and visible on both faces of the wall.

7.8 In stone walls with a rubble filled cavity, the two skins are first injected using techniques appropriate to the substrate.  In walls 450 mm thick, the holes in one leaf are redrilled to the centre of the wall (into the rubble infill) and injected singly until fluid exudes from mortar joints below the injection level.

7.9 Walls of greater thickness are drilled and injected the same way from both sides, for example 600 mm walls are drilled to a depth of 200 mm and each hole is injected singly until fluid exudes from the mortar joints below the injection level.

7.10 4.5 litres of fluid are normally used for the treatment of the rubble core in 1 metre of a 450 mm wall.

7.11 In walls of rubble filled construction, untreated walls are isolated by the injection of a vertical damproof course throughout the thickness of the wall.

7.12 The treated walls are left for a period of at least 14 days to allow initial drying out.   Internal plastering is applied as outlined in Antel Replastering Specification.  Particular care is taken to avoid bridging the injected damproof course, both internally or externally.  Where external rendering has been removed, it is restored, ending in a bell casting above the injected damproof course.  Holes in the external wall surfaces are plugged with sand/cement mortar or preformed plastic plugs coloured to match the existing wall surface.

In buildings with a history of penetrating damp, a spray treatment of Antel Silicone Water Repellent  is applied to prevent recurrence and possible build up of water above the damproof course.

8.   GENERAL

The Antel injected damproof course system is satisfactory for use to provide a barrier against rising damp in existing solid walls up to 600 mm thick.  Existing walls of conventional cavity construction and existing walls of rubble filled construction where there is no damproof course or where an existing damproof course has failed.

9.   ACTION WITH RESPECT TO

FLOORING TIMBERS

9.1 Where a suspended timber floor is independently supported on sleeper walls, with an effective damproof course, these need not be treated.

9.2 Where a suspended timber floor is supported on joists and/or a wall plate bearing on or embedded in the wall, there is a possibility of decay, particularly where concealed timbers are in contact with the wall.  The condition of these timbers should be ascertained and remedial action taken if necessary.

9.3 If damage is limited to the joist ends, the floors may be reformed using sleeper walls or joist hangers to isolate the timbers from the damp wall.

9.4 If the timbers are sound, the existing floor may be retained, provided the injected damproof course is formed below the timber joists and/or wall plates

10.   DRYING OUT OF WALLS

A 230 mm solid brick wall affected by rising damp and treated will normally dry out in 6 - 12 months provided normal heating is used during the winter months.  This period may be exceeded for walls of greater thickness.  Where hygroscopic salts are present adequate drying may not occur, but the replastering system will prevent damage to internal decorations.

11.   POINT OF CAUTION

The injection fluid can dissolve expanded polystyrene and so the injection into cavity walls containing this form of insulation should not be attempted.  However expanded polystyrene insulation may be used after the injection and cure of the fluid in the cavity wall.

12. RUBBLE FILLED CAVITY CONSTRUCTION

By its nature the structure and the composition of the rubble infill is variable.  Consequently it is impossible to achieve an effective treatment with certainty.  Incidence of failure is however small.  Rectification by re  treatment of the affected areas (using an increased volume of fluid) is often achieved.