Painting Pitched Roofs

Transcription

1 4 Tutorial 4 Painting Pitched Roofs Tile & Galvanized Iron Paint Academy Determining your product requirement: Measure area to which paint is to be applied. Depending on surface to which the product is to be applied, determine which products are needed. (Refer to Product Specifier Tool) Check the s (TSR) on each of the specified products and see how many coats of each are recommended, then calculate what quantities of each product you will require, remembering to make adjustments for the porosity of each surface. TSRs are based on products applied to smooth, sealed surfaces. (e.g. an unsealed scratch plaster surface will absorb more paint than a sealed smooth one, so allow for a lower spread rate). Check out the specifications on all the top coat choices (referring to the relevant data sheets) and decide which is right for you. Tile Roofs If Unpainted Tile Roof 1. Ensure tiles to be painted are free of loose friable material by washing. Allow to dry. 2. Replace broken tiles 3. If algae is present, poison with as per Description and Application Data Sheet 1. Apply 1 coat AcrySeal directly to roof with a brush, roller or airless spray. (Rough tiles diluted AcrySeal 1 litre to 0.5 litre water, Smooth tiles diluted 1:1 with water). Allow to dry. 2. Patch all ridging with FlashPatch or AcryLatex and cement. Allow to dry. (See AcryLatex Description and Application Data Sheet) 3. Apply 2 coats undiluted directly to roof with a brush, roller or airless spray. Allow to dry. Relevant Product Information 1 : 19 Page 1

2 AcrySeal FlashPatch AcryLatex Dilution Do not apply thicker than 5mm per application. Trowel or 25 C 1 25 C - 7 Days (when combined with cement mix) 1:1 with water 8m² per litre (Use Under all -Based Acrylic Paint Systems) : Formulated as a Multipurpose Incredibly Strong and Flexible Patching and Skimming Compound that has Excellent proofing qualities. & Skimming Compound (Alkali & Acid Resistant) Application: Patch in layers no thicker than 5mm at a time. Exterior Crackfiller Formulated for proofing and Damp Proofing, Improving Flexibility, Adhesion, Strength and Durability of Plaster. For Repairs to Large Damaged Cementatious Surfaces. (Use to Wet Sand & Cement Mixtures Instead of ) High Strength No Dilution - Normal Rate 1:1 with Cement Modifier : If Previously Painted Tile Roof 1. Check adhesion of existing paint system. (Cross hatch adhesion test). Using a Stanley knife, cut through the paint surface to the substrate vertically and horizontally approximately 3mm apart, creating little squares. If the edges of the squares curl up, and the square can easily be removed, this means the adhesion of the old paint system is failing. If the paint system is failing, remove all old paint back to the existing tile. 2. If the old paint s adhesion is still good wash roof down to remove any dirt, dust or old chalking paint. Allow to dry 3. Treat for algae if necessary with Algae Killer. Dilute 1litre to 19 litres water, apply to algae and leave for 24 hours, then remove dead algae and by washing down with water and allow to dry. 1. Apply 1 coat AcrySeal to tiles if chalking paint has been washed off the exposed tiles, diluted 1:1 with water. Allow to dry. If the old paint is clean with no chalk on it then it is not necessary to apply AcrySeal before painting 2. Patch all ridging with FlashPatch or AcryLatex and cement. Allow to dry (see product related Description and Application Data Sheet) 3. Apply 2 coats undiluted directly to roof with a brush, roller or airless spray. Allow to dry between coats. Page 2

3 Relevant Product Information AcrySeal FlashPatch AcryLatex No. of Coats required Dilution No. of Coats required Trowel or 25 C 1 25 C - 7 Days (when combined with cement mix) 1:1 with water 8m² per litre (Use Under all -Based Acrylic Paint Systems) 1 : 19 : Formulated as a Multipurpose Incredibly Strong and Flexible Patching and Skimming Compound that has Excellent proofing qualities. & Skimming Compound (Alkali & Acid Resistant) Application: Patch in layers no thicker than 5mm at a time. Exterior Crackfiller Formulated for proofing and Damp Proofing, Improving Flexibility, Adhesion, Strength and Durability of Plaster. For Repairs to Large Damaged Cementatious Surfaces. (Use to Wet Sand & Cement Mixtures Instead of ) High Strength No Dilution - Normal Rate 1:1 with Cement Modifier : Galvanized iron Roofs If Unpainted 1. Ensure roof to be painted is free of any contaminants by washing and degreasing with GrimeReaper rinse well and allow to dry. 2. Remove rust, if any back to bright metal using sandpaper and remove sanding dust. 1. Apply 1 coat AllPrime to areas where rust has been removed. Allow to dry. 2. Now apply 1 coat AllPrime to the entire roof and allow to dry. This means that areas where dust has been removed, will be covered by 2 coats of AllPrime. 3. Finally apply 2 coats to the roof with a brush, roller or airless spray. Allow to dry. Page 3

4 Relevant Product Information AllPrime Primed Steel: 12m² per litre Mild Steel: 2 coats Rust free Galvanized Iron: 1 coat Formulated for Mild Steel and Galvanised Iron. Incorporating Non Toxic Anti-Corrosive Pigments Modified Acrylic Co-Polymer Primer : 10-12m² per litre 8-9m² per litre Previously painted Galvanized iron Roof (Peeling paint) : 1. Check adhesion of existing paint system. (Cross hatch adhesion test). Using a Stanley knife, cut through the paint surface to the substrate vertically and horizontally approximately 3mm apart, creating little squares. If the edges of the squares curl up, and the square can easily be removed, this means the adhesion of the old paint system is failing. If the paint system is failing, remove all old paint back to galvanized metal. 2. If the adhesion of the old paint system is still good wash roof down to remove any dirt, dust or old chalking paint. Allow to dry 3. Treat for algae if necessary with Algae Killer. Dilute 1litre to 19 litres water, apply to algae and leave for 24 hours. Wash the entire area down with water to remove dead algae and and allow to dry. 4. If there is any rust using sandpaper sand down these areas to bright metal and remove sanding dust. 1. Apply 1 coat AllPrime to areas where rust has been removed. Allow to dry. 2. Apply 1 coat AllPrime directly to the entire roof with a brush, roller or airless spray. This means that rusted areas will have 2 coats of AllPrime. Allow to dry. 3. Apply 2 coats directly to roof with a brush, roller or airless spray. Allow to dry. Previously painted galvanized iron Roof (If old paint adhesion is still good) 1. Wash roof down to remove any dirt, dust or old chalking paint. Allow to dry 2. Treat for algae if necessary with Algae Killer. Dilute 1litre to 19 litres water, apply to algae and leave for 24 hours, then remove dead algae. 3. Should there still be trace of chalk on the surface of the old paint after washing, then apply 1 coat AcrySeal diluted 1:1 with water. Allow to dry. If the old paint system is clean with no chalk then AcrySeal is not required before painting. Page 4

5 1. Apply 2 coats Ruvacryl over sealer or over cleaned old paint. Allow to dry between coats. Relevant Product Information AllPrime AcrySeal Primed Steel: 12m² per litre Mild Steel: 2 coats Unrusted Galvanised Iron: 1 coat 8-9m² per litre Formulated for Mild Steel and Galvanised Iron. Incorporating Non Toxic Anti-Corrosive Pigments Modified Acrylic Co-Polymer Primer : 10-12m² per litre (Use Under all -Based Acrylic Paint Systems) : : 1 : 19 Page 5