Intergrain Heavy Duty is a semi-transparent, high build, water based exterior timber finish. Heavy Duty is designed to protect timber with a tough, UV, water and mould resistant finish offering superior durability for harsh weather conditions and is available in a range of tinted colours.
Cleaning materials
Water
Application Tools
Spray, Brush, Pad
All timber is required to be free from dust, mould and site contaminants prior to coating.
Follow all relevant product label instructions when using Intergrain products.
Keep freshly coated contacting surfaces such as doors and windows ajar for several days to prevent sticking.
Do not apply to hot surfaces or those in direct sunlight, as doing so will result in difficult application, poor adhesion and blistering.
Do not apply in temperatures above 35°C or below 10°C or if rain or dew is expected within four hours of application. Lightly dampening timber before painting will ease application in temperatures above 28°C.
The instructions below offer general preparation guidelines. For larger projects, commercial jobs or for more specific information please contact our Help & Advice team.
New, pre-oiled timber
Timber that is factory pre-oiled with Intergrain Universal Timber Oil or Feast Watson Industrial Timber Oil does not require exterior weathering or treatment to remove tannin or oils. This pre-oiled timber can be directly over coated with Intergrain Heavy Duty.
All timber should be clean and free from dust, dirt, debris, and mortar prior to coating. Light surface soiling: A light wipe down with a clean damp cloth will be suitable. Heavy surface soiling: Clean the surface with Intergrain UltraPrep Timber Cleaner following the directions on the pack and rinse, allowing the surface to dry thoroughly prior to topcoat application.
IMPORTANT
Prior to topcoat purchase and application, it is important to identify the type of oil the supplier or timber merchant has used, to ensure it is compatible with water-based oil application. If unsure, follow the recommendations below for New Raw Timber.
New raw timber
Treat timber with Intergrain UltraPrep Tannin & Oil Remover. Then clean with Intergrain UltraPrep Timber Cleaner.
Grey and weathered with no previous coating
Clean with Intergrain UltraPrep Timber Cleaner. For severely weathered timber, sand back to a fresh surface, remove all sanding dust, then clean with Intergrain UltraPrep Timber Cleaner.
Existing coating in poor condition
Remove coating by using a combination of Intergrain UltraPrep Tannin & Oil Remover and power washing. Then clean with Intergrain UltraPrep Timber Cleaner.
Paints, varnishes or coatings in varied condition
Paints, varnishes or coatings that have deteriorated unevenly, remove all existing coating by using Intergrain Liquid 8 Timber Stripper or sanding back to bare timber. Then clean with Intergrain UltraPrep Timber Cleaner.
Maintenance coat of Intergain Heavy Duty
If your existing Intergrain Heavy Duty coating is in good condition, clean the surface with Intergrain UltraPrep™ Timber Cleaner.
Important: If mould is present or if timber is in a mould prone area, use Intergrain UltraPrep Mould Killer to remove surface mould effectively as the first step of preparing the timber for coating.
Remove excess water from the surface and allow the timber to dry for at least 1 hour before coating. Stir Intergrain Heavy Duty thoroughly before and during use with a flat blade stirrer. Apply Intergrain Heavy Duty using the Intergrain DeckBrush™ (recommended), flat deck applicator, paint brush or spray (air assisted airless or airless). Do not use a roller. Do not thin product.
It is recommended to test in a small area to ensure satisfaction with the colour and finish prior to coating the whole project, ensure to apply 2–3 coats for the best indication of final colour.
Apply three coats of Intergrain Heavy Duty, taking care to apply sufficient product to edges and ends. Four coats will be required in extreme conditions such as full sun exposure, around pools and in humid areas and may be required on porous timbers.
Allow 4 hours between coats. Apply at the correct application rate (see coverage). Do not overspread or apply thinly as insufficient film thickness will compromise performance and durability. When coating large areas, work in sections, apply long strokes and use natural breaks in the boards as stopping points. If spraying, it is recommended to back brush to even out the finish and avoid spotting. If necessary, sand lightly between coats to remove any raised grain and remove sanding dust.
Maintenance
Conduct a routine 12 monthly maintenance inspection. Colour fade is the first sign of need to recoat. To prevent water ingress and peeling, ensure Intergrain Heavy Duty is recoated before deterioration of the coating and timber underneath occurs.
