DPC Microjet - Aqueous Concentrate

7. INSTALLATION

7.1 The course to be injected is chosen so that the position of the horizontal damp-proof course complies, as far as practicable, with the recommendations of BS Code of Practice 102:1973 (Protection of buildings against water from the ground). E.g. The damp-proof 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. Complimentary vertical damp-proof course are positioned, where necessary, to isolate treated walls from the effects of rising damp in adjoining walls or to maintain continuity between horizontal damp-proof courses at different levels.

7.2 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 damp-proof course line is exposed where necessary by removing any facing material.

7.3 In brickwork, 10 mm or 14 mm holes are drilled to predetermined depths along the selected course. Two holes are drilled in each stretcher and one in each header, to an average spacing of approximately 120 mm and a maximum spacing of 150 mm.

Drilling may be carried out in the two related horizontal and connecting vertical mortar courses, the holes being not 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 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.

7.4 Injection of the solution is carried out at a normal pressure of 350 kPa, but this may be reduced in the case of very porous brickwork. 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. Where the face of the brickwork cannot be observed e.g. for the double and triple drilling technique described in a metered or timed quantity of fluid determined by the initial injection or by prior test upon an exposed section of the section of the second or third leaves, should be pumped into the wall After injection, the nozzles are removed and subsequent holes are similarly injected.

7.5 In solid or cavity walls of conventional construction in blockwork or stone the drilling and injection procedure is adjusted to accommodate variations in the density, porosity and structure but in each case the procedure ensures a continuous unbroken band of impregnated material along the length of the wall.

7.6 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 the Replastering Specification.

7.7 Particular care is taken to avoid bridging the injected damp-proof course. All holes in the external wall surfaces are plugged with cement sand mortar coloured to match the existing wall surface.

7.8 In buildings with a history of penetrating damp a spray treatment of Antel Water Repellent Microshield is applied to prevent recurrence.

9. GENERAL

9.1The Antel Aqueous DPC Pressure Injection damp-proof course system is satisfactory for use to provide a barrier against rising damp in existing solid walls of brickwork, blockwork or stone (excluding flint) up to 600 mm thick, or existing walls of conventional cavity construction, where there is no damp-proof course or where the existing damp-proof course has failed.

9.2 Replastering is necessary to retain salts in the body of the wall and to prevent damage to subsequent redecoration. Replastering must be in accordance with the Antel Replastering Specification.

10. ACTION WITH RESPECT TO FLOORING TIMBERS

10.1 Where a suspended floor is independently supported on sleeper walls, with an effective damp-proof course, no injection is necessary.

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

10.3 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 walls.

10.4 If the timbers are sound the existing floor may be retained provided the injected damp-proof course is formed below the timber joists and/or wall plate.

11. DRYING OUT OF WALLS

A 230 mm solid brick wall affected by rising damp and treated with Antel Aqueous DPC pressure injection system should 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.

12. CLEANING

Wash equipment with fresh clean water.

Packaging: Available in 5-litre plastic bottles, with 4 bottles per case.

Usage Rate: Typically 4.5 litres per metre of a 450mm thick wall. Adjust for thicker walls.

Storage: Store in cool, dry conditions. Protect from freezing and keep out of reach of children.

Dilution: Dilute with clean water to make 25 litres of injection fluid.

Injection Pressure: Standard injection pressure is 350 kPa, adjustable for porous materials.

24-48 Hour Dispatch

We pride ourselves on fast and reliable delivery. Most orders are dispatched promptly and typically arrive within 24-48 hours, subject to stock availability and courier schedules.

If there are ever any unexpected delays, our team will keep you informed as soon as possible.

For larger or ongoing projects where additional quantities may be required later, we recommend contacting us in advance so our team can help check current stock availability and product continuity for your project.