Where extensive plaster and fine hairline cracking is present, cracks must be repaired and the entire wall (from corner to corner) must be coated. We highly recommend using either two coats of Professional Waterproofing and Crack Bridging Compound or Plascon Multiseal – thinned up to 5% with water (to avoid a structured finish), and applied at a wet film thickness of 400µm per coat – allowing 4 hours drying at 23°C between coats.
Corner to Corner Hairline Crack Repair Step-by-Step Guide
- First step for hairline crack repair is to remove all peeling and flaking paint. All surfaces must be clean, firm and dry before painting.
- Repair and fill any cracks. With plaster cracks (less than 4mm) open cracks to a minimum of 3mm wide and deep, remove dust and prime inside of crack with Plascon Plaster Primer and allow it to dry for 16 hours.
- Fill cracks with Polycell Polyfilla Mendall 90 using a scraper, smoothing off whilst still wet. Sand smooth after 8 hours then patch-prime repaired areas with Plaster Primer. Allow the primer to dry for 16 hours.
- Apply one coat of Plascon Multiseal over the repaired areas and hairline cracks and leave it to dry for 4 hours.
- Finish with two coats of Plascon Micatex. This is a finely-textured exterior matt paint, formulated for protection against the toughest weather conditions also contains “mica for stretch and marble for strength” to cover and prevent hairline cracks.
Please Note: Plascon Dampseal is only used for rising/penetrating damp not more than 1.1meters above ground level.