Surface Prep: Nuroof Cool

Surface Preparation Guide for Nuroof Cool

Plascon Nuroof Cool Premium

  • Surfaces must be clean, firm (sound) and thoroughly dry before painting.
  • Remove any fungal growth or algae with household bleach (3.5% solution of sodium hypochlorite) thinned 2 parts bleach to 1 part water by volume.
  • Leave on surface for approximately 1 hour, then scrub with a hard bristle brush to remove all dead growth.
  • Rinse thoroughly with fresh water and allow to dry.
  • Repair leaks and defective flashing with PLASCON ROOFSEAL MEMBRANE.

1. Galvanised Iron:

1.1 New: Remove fabricators pre-treatment oil, grease and any other contaminants with METALCARE GALVANISED IRON CLEANER. Hose and scrub down with a hard bristle brush and fresh water and repeat cleaning process until a water break-free surface is obtained. Prime with METALCARE GALVANISED IRON PRIMER.

1.2 Unpainted and weathered: Remove oil, grease, white rust or any other contaminants with METALCARE GALVANISED IRON CLEANER to achieve a water break-free surface. Rinse thoroughly with fresh water. Then prime with METALCARE GALVANISED IRON PRIMER. Areas showing red rust must be abraded back to bright metal, patch primed with PLASCOSAFE 18 PRIMER and then the whole surface primed with METALCARE GALVANISED IRON PRIMER.

1.3 Previously painted and weathered: Clean with high-pressure water jet to remove all loose paint, chalk and dirt. Alternatively, clean with wire brushing, scraping, sanding, etc. and then scrub down with hard bristle brush and water. Treat any bare areas as in 1.2 above.

2. Fibre-Cement Sheeting:

2.1 Unpainted and weathered: Remove dust, dirt, loose granules, friable and powdery material with high-pressure water jet or alternatively scrub down with a hard bristle or wire brush and water. Allow surface to dry. Prime with BONDING LIQUID. Allow to dry for at least 4 hrs @ 23°

2.2 Previously painted in good condition: Remove dust, dirt, loose granules, friable and powdery material with high-pressure
water jet or alternatively scrub down with a hard bristle or wire brush and water. Allow surface to dry.

2.3 Previously painted in poor condition: Strip completely. Restore powdery and friable surfaces to a sound condition before painting by applying BONDING LIQUID. Allow to dry for at least 4 hrs @ 23 °C. Apply NUROOF COOL (TRP 200 Range) before contamination of the surface can take place (within 48 hrs).

3. Cement Tiles & Granular Tiles:

3.1 Unpainted and weathered: Remove dust, dirt, loose granules, friable and powdery material with high-pressure water jet or alternatively scrub down with a hard bristle wire brush and water. Allow surface to dry. Prime with BONDING LIQUID as per instructions on the Technical data sheet. Allow to dry for at least 4 hrs @ 23 °C. Apply NUROOF COOL (TRP 200 Range) before contamination of the surface can take place (within 48hrs).

3.2 For previously painted roofs in good condition: Remove dust, dirt, loose granules, friable and powdery material with high-pressure
water jet or alternatively scrub down with a hard bristle or wire brush and water. Allow surface to dry.

3.3 Previously painted in poor condition: Strip completely. Restore powdery and friable surfaces to a sound condition before painting by applying BONDING LIQUID. Allow to dry for at least 4 hrs @ 23 °C. Apply NUROOF COOL (TRP 200 Range) before contamination of the surface can take place (within 48 hrs).

4. Zinc Alum & Aluzinc:

Clean surface thoroughly with POLYCELL SUGAR SOAP POWDER solution. Rinse thoroughly with clean water to neutralise. Allow to dry. Prime with PLASCOSAFE 18 PRIMER.

5. Chromadek:

Clean surface thoroughly with POLYCELL SUGAR SOAP POWDER solution or REMOVALL HIGH STRENGTH CLEANER & DEGREASER and scouring pads to remove chalk. Rinse thoroughly with clean water to neutralise. Allow to dry. Prime with EPIWASH STRONTIUM CHROMATE PRIMER.

6. Special Caution Tiles:

N.B. The painting of clay, slurry coated tiles, slate and wooden shingles is NOT RECOMMENDED.

7. Extremely Porous Surfaces: unpainted cement and well-weathered tiles:

Remove dust, dirt, loose granules, and friable and powdery material with a high-pressure water jet or by scrubbing with a hard bristle or wire brush and water. Allow surface to dry. Apply undiluted BONDING LIQUID (refer to technical data sheet for application details). Allow to dry for at least 4 hrs @ 23 °C before applying NUROOF COOL (TRP 200 Range). Overcoat before contamination of the surface can take place (within 48 hrs).

>> Download the Nuroof Cool Data Sheet <<

31 thoughts on “Surface Prep: Nuroof Cool

  1. I have a chromadek roof and can already tell (from online inquiries) that I have a problem with the primer availability. I stay in Midrand. Who would you suggest as the closest supplier? Can the EPIWASH STRONTIUM CHROMATE PRIMER be applied using a normal bristle brush?

    • Hi Dumi, thanks for getting in touch.

      We advise going to your nearest Builders store (i.e. Builders Express or Builders Warehouse). They will be able to advise you further, but yes, you can use a bristle brush to apply the product.

  2. I have a corrugated COLORBOND roof made in Australia that needs painting. Decided on Plascon NUROOF COOL. Is the primer same as for Zincalume?

    • Hi Keith, thanks for your query. Here’s what you need to do:

      1. Scrub the surface thoroughly with POLYCELL SUGAR SOAP POWDER solution (500g into 5 Litres water). Use scouring pads to remove chalk and contaminants.

      2. Rinse thoroughly with clean water to neutralise and allow to dry.

      3. Prime with PLASCON EPIWASH STRONTIUM CHROMATE PRIMER (AW 255) and allow 1 hour to dry but not more than 14 days before over-coating.

  3. Hi there, I hope you can help me with this problem. I have a chromadekroof on my wine cellar. I clean the roof with high pressure machines and then paint it. In less than a year the dry fungus just comes back. What chemicals can I use to get rid of it?

    • Hi Louis, thanks for getting in touch.

      House-hold bleach is quite effective against fungus. One can try the use of a two-part water to one part JIK solution to spray the roof and then wash it off. This will need to be done quite often at first.

  4. Good day, I have a fairly old house with an asbestos garage roof I would like to paint it I am going to high pressure clean it must I use a bonding liquard or plaster primer before I paint of can I just paint directly onto the asbestos.

    Thank you

    • Hi Ivan, thank you for your query.

      Before we can advise you, please could you kindly inform us as to whether or not the roof has been painted before? If so, can you specify what product may have been used or if it is oil-based or water-based?

    • Hi Ivan, we have just published a simple method for determining whether a previously painted surface was painted with solvent based or water based paint:

      “Dip a clean cloth into some methylated spirits and rub it on the paint surface. If the paint comes off on the cloth, then it is water based. If not, it is a solvent based coating that was previously used on the surface.”

  5. We drink rainwater from our roof. We are busy painting our asbestos roof with Nuroof. Should we leave the gutters off for a while to let the paint ‘cure’ so as not to contaminate the runoff into the tank? Thank you for your prompt reply!

    • Hi Allan, thanks for getting in touch. Please note that due to South African law, we are prohibited from giving advice on painting asbestos. Furthermore, we cannot recommend any Plascon paint be used where it will come into contact with drinking water.

  6. I would like to know if Nuroof is the correct application for painting the underside of roof sheeting that gets no direct sunlight or rain? Or will the application of enamel work too? The reason for my question is we have a courtyard that is enclosed with a sheet metal roof and the area is dark. I would like to brighten up the space by painting the underside of the sheeting white.

    • Hi Robert, thank you for inquiring. Here’s what you need to do:

      For unpainted and weathered surfaces: Remove oil, grease, white rust or any other contaminants with Metalcare Galvanised Iron Cleaner to achieve a water break-free surface. Rinse thoroughly with fresh water. Then prime with Metalcare Galvanised Iron Primer (GIP 1). Areas showing red rust must be abraded back to bright metal, patch primed with Plascosafe 18 Primer (EMS 18) and then the whole surface primed with Metalcare Galvanised Iron Primer (GIP 1). Finally, apply 2 coats of Plascon Nuroof white.

  7. I would like to check what surface temperature is suitable for application of Plascon NuRoof Cool – even on cool days, galvanised iron roof sheeting quickly reaches temperatures in excess of 50 degrees C (right now the air temperature is only 25 deg. but my roof surface temperature is over 50). Is there a recommended minimum and maximum surface (and/or air) temperature for application? I can find only an indication of how long to allow a washed roof to dry at a given temperature before painting…

    • Hi Peter, thanks for getting in touch. Please note that your roof surface needs to be between Min: 10 °C to Max: 50 °C for you to be able to apply Plascon NuRoof Cool. Please find attached in the link provided the data sheet for this product which contains all the information you need regarding surface preparation and application.

  8. I just bought a 40 year old house in the Karoo with a corrugated galvanized iron roof. The paint is peeling off in some places and I am busy brushing off the whole roof with wire brushes. At most places the old paint still sits. I have bought your Nuroof Cool in white. Can I apply the paint directly or do I need further preparation and an undercoat? Do I need a second coat? What about the underside of overhangs that is also peeling off?

    • Hi Hendrik, thanks for getting in touch. Here’s what you need to do:

      You will need to remove as much of the old paint as possible. Is the old paint water-based or oil-based? If oil-based then you will need to remove all of the paint. Remove faulty paint and scrub entire area with a Polycell Sugar Soap Powder solution (500g into 5L water). Clean with a high-pressure water jet to remove the sugar soap solution, chalk and dirt.

      Unpainted: Remove oil, grease, white rust or any other contaminants with Metalcare Galvanised Iron Cleaner (GIC 1) to achieve a water break-free surface. Rinse thoroughly with fresh water. Then prime with Metalcare Galvanised Iron PRIMER (GIP 1).

      Areas showing red rust must be abraded back to bright metal, patch-primed with Plascosafe 18 Primer and then the whole surface primed with Metalcare Galvanised Iron Primer. Once dried, apply 2 coats of Plascon Nu Roof Cool.

  9. I am about to do a roof with Plascon NuRoof that was painted 3 years ago and the paint is still in very good condition. Instead of using a spray jet, can I use a mixture of household bleach and water to clean the entire roof without sanding it first? And if yes, will the paint grip if not sanded?

    • Hi Johnny, thank you for querying with us.

      Please can you confirm what paint is currently on the surface and what type of roof you have? Please note that a bleach mixture is normally used to clean fungus or mould.

  10. It’s a corrugated profile roof done 3 years ago with a water-based roof paint. Can you advise as to what cleaning method I should use prior to painting please.

    • Hi Johnny. Thank you. Here’s what you need to do:

      For Previously Painted: Carry out adhesion tests on previous coating. Cross cut test to ISO 2409 standard. Remove faulty paint and scrub entire area with a Polycell Sugar Soap Powder solution (500g into 5 L water). Clean with high-pressure water jet to remove sugar soap solution, chalk and dirt. Treat any bare areas as below:

      Remove oil, grease, white rust or any other contaminants with Metalcare Galvanised Iron Cleaner (GIC 1) to achieve a water break-free surface. Rinse thoroughly with fresh water. Then prime with Metalcare Galvanised Iron Primer (GIP 1). Areas showing red rust must be abraded back to bright metal patch primed with Plascosafe 18 Primer (EMS 18) and then the whole surface primed with Metalcare Galvanised Iron Primer.

      You can then apply 2 coats of Plascon NuRoof Cool.

  11. Hi Plascon, Can I directly paint NuRoof on IBR polycarbonate sheets? I have got semi-transparent IBR sheets and they get so hot in summer.

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