Wykamol Microtech PIF Damp Proofing Fluid

Mixing:

Microtech PIF a concentrated solution and should be diluted at a rate of 1 : 11.5 parts water.

Typically, a 2 Litre bottle makes 25 Litres of diluted, ready-to-use solution.

Substrate Preparation:

Check and overhaul rainwater goods and soakaways to ensure that they are in good order and clean, repair or install drains to carry away surface water.

If the internal floor level is at or below external ground level, form trenches along the external face of the walls to at least 150mm (6”) below the proposed DPC level.

Do not excavate below footing level or affect the structural stability of the wall.

Carry out any repairs or re-pointing and leave to cure (minimum 6 weeks) before installing the DPC. Remove skirtings, fixings and plaster to expose the line of the proposed DPC. Plaster which may be affected by hygroscopic salts should be removed to not less than 300mm (12”) above the last visible signs of dampness or 1m above the proposed line of the DPC, which ever is the higher.

Check the removed skirtings and, if required, put sound items to one side for reinstatement.

Inspect other associated joinery and flooring timbers and if fungal decay is located take the appropriate remedial measures (see separate Data Sheets). Ensure wall cavities are clear of debris.

Remove external render to expose the line of the proposed DPC. If it is suspected that the render is contaminated by hygroscopic salts and/or is physically unsound, it should be removed to an appropriate height (see above). In the case of a semi-detached/terraced houses etc. Inform occupants of adjoining properties before treatments commence. The drilling of party walls in particular may cause disturbance to decorations / ornaments.

Cavity fill materials such as urea formaldehyde, polystyrene and mineral wool will not be affected but the fluid may damage/stain certain types of floor coverings and adhesives and present a contact hazard to unprotected persons. In case of spillage wipe up immediately. Rinse with water and detergent. Do not allow fluids to come in contact with glass.

Dilution of Concentrate in a labelled clean Plastic Drum, add 2 litres of concentrate. Switch on the mechanical stirrer. Add water slowly whilst stirring. Continue to add water until the dilution becomes more liquid. Add the rest of the water slowly whilst continuing to stir.

The mixing time depends upon the mixing device and speed. Before and after use, ensure pump equipment is thoroughly washed out with clean water.

Application Method:

General
Select the course to be treated. This should be at least 150mm (6”) above external ground level. Where suspended timbers are present, the DPC should be formed below joist/wall plate level wherever possible. In the case of solid floors, the DPC should be inserted as close to the floor as possible. Vertical DPC’s should be installed to connect staggered DPC levels and to isolate untreated wall areas, e.g.. adjoining properties, fireplaces not treated due to lack of access and abutting garden walls. The vertical DPC should extend to at least 1200mm above DPC level If very high levels of hygroscopic ground salts (chlorides, nitrates) are present in the property, (e.g. in areas of brackish water), the Wykamol Technical Department should be consulted regarding suitable methods of treatment and reinstatement.

Brickwork
Drill the selected course at spacings 120 - 150 mm apart (2 per stretcher, 1 per header) to an average depth of 75mm. The diameter of the holes should be between 10 - 15mm dependant on the injector rods used. Single skin (115mm) walls are drilled from one side (avoid percussion drills). Solid walls (230mm or more) should, where possible, be treated from both sides. If access is restricted injection can be carried out from one side. The first brick is treated normally. A hole is then drilled through into the next brick skin and injection undertaken using the time taken for successful treatment of the first brick as a guideline. Walls of greater thickness’s may be similarly treated in an incremental manner.

Treatment may be carried out into the mortar course if required using a similar drilling pattern (150mm spacings). The course selected should allow reasonable pressure retention during injection and a lower pressure and longer injection times used to achieve good continuity of treatment (see “Injection below”). A combination of mortar joints and brickwork can be treated by using the brick drilling pattern above but drilling at an angle to end in a mortar joint at the level of the proposed DPC.

Stonework
Treatment of solid stonework should be carried out in a similar manner to “Brickwork” with adjustments being made to the drilling pattern to take account of the construction.

Rubble Infill Walls
Both solid external skins should be treated in a similar manner to “Brickwork”. One set of drill holes can then be drilled through into the centre of the wall and the rubble infill treated.

Injection
Injection is carried out by inserting injector rods into the drilled holes and forming a seal. The DPC material is then injected at pressure of approximately 500 kPa (70 lbs / in²) until a continuous band of treatment is visible on the face of the wall. If treatment is being carried out into the mortar joints the pressure should be reduced to 350 kPa (50 lbs/ in²). In saturated walls, lower pressures (ca. 100 kPa) over longer periods of time are likely to be most successful. In all cases, care needs to be taken to ensure the recommended levels are achieved.

NB: It is essential that fluid loss is kept to a minimum to ensure continuity of the injected DPC. If a pressure drop is experienced or a poor seal suspected, injection should stop and a fresh hole drilled nearby before attempting treatment once more.

Reinstatement:

Re-Plastering
Ideally, re-plastering should be deferred as long as possible to encourage drying but a minimum of 14 days between treatment and re-plastering should be allowed.

Re-plastering work should be carried out in accordance with Wykamol Re-plastering Specifications. All replaced skirtings etc. should be either pre-treated or treated with a suitable preservative such as Microtech Dual Purpose or Wykabor 10.

Drying Time / Redecoration
After the insertion of a DPC, the residual water in the wall must evaporate before normal dry conditions are achieved. The time will vary according to the amount of water present and the thickness of the wall but one month per 25mm (1”) thickness of wall is quoted as a guideline. Redecoration should be regarded as being temporary until the wall has dried out.

External Works
Where appropriate, external renders should comply with the requirements of BS 5262 : 1991 and terminate with a bell mouth just above the DPC level. External drill holes should be filled with a suitably coloured sand / cement mix, or DPC Plugs.

Coverage:

Approximately 3.5 litres per metre run of 225mm (9”) wall depending on the porosity and nature of the substrate.

Consumption in walls of a greater thickness should be calculated pro-rata (rubble infill walls may be regarded as solid structures).

Technical Data Sheet

Safety Data Sheet