CEN/TC 139/WG2Coatings for Exterior Wood

Peter SvaneCoating Consultancy Copenhagen

Administrative

Convenors• E R Miller BRE UK 1989-2003• G. Hora WKI D 2003-2005• P. Svane CC DK 2005-

Secretariate• B. Reinmüller DIN D 1989-

Members• Austria• Belgium• Denmark• Finland• France• Germany• Italy• Netherlands• Norway

• Poland• Portugal• Spain• Sweden• Switzerland• United Kingdom

• (11 active)

Coatings for Exterior Wood

Coatings for Exterior Wood

• Coating Materials

• Coating systems

Coating systems

Standards• EN 927-1 Classification + selection• EN 927-2 Specifications• EN 927-3 Natural weathering test• EN 927-4 Withdrawn• EN 927-5 Water absorption test• EN 927-6 Accelerated weathering test• prEN 927-7 Knot staining test• prEN 927-8 Adhesion test• prEN 927-9 Tannin staining test

Classification of coating systemsEN 927-1

• End use

• Appearance

• Exposure conditions

• Non stable• Semi-stable• Stable• Build• Hiding power• Gloss• Mild • Medium• Severe

Complying with specifications

927-1Classification

927-2Specification

927-3Weathering test

927-5Water abs. test

EN 927-3

EN 927-3

EN 927-3 assessments

• Gloss• Colour• Chalking• Mould growth

Informative

• Blistering• Flaking• Cracking• Adhesion

Required to complywith specs (EN927-2)

EN 927-3 Panels

EN 927-3 Water trap

EN 927-3 Ordinary

Mould growth assessment

?

Adhesion measurement

• Cross cut test (ISO 2409)

• ?

EN 927-5

72 h water absorption from EN 927-5/ specifications in EN 927-2

Standards• EN 927-1 Classification + selection• EN 927-2 Specifications• EN 927-3 Natural weathering test• EN 927-4 Withdrawn• EN 927-5 Water absorption test• EN 927-6 Accelerated weathering test• prEN 927-7 Knot staining test• prEN 927-8 Adhesion test• prEN 927-9 Tannin staining test

EN 927-6: Accelerated weathering test

prEN 927-7: Knot staining test

prEN 927-7: Knot staining test

prEN 927-7: Knot staining test

• Pinus sylvestris, sapwood with knots• Climatising• Machining, planing• 14 days pause• Coating• 3 days artificial exposure (EN 927-6)• Colour measurement on knots / background

17 years: 5 standards

• Is it worth it ?

• What did we do wrong ?

• How can we do better in the future ?

What did we do wrong ?

• Atmosphere unpleasant during first years• Weak user representation• Difficult rel. with National standardisation bodies

• Compromises instead of documented solutions• Gap between members and ”lab-guys”• Description sometimes ambigeous• Poor graphics

From EN 927-5

How can we do better in the future ?

• Social aspects• User representation ?• What is the role of National stand. bodies ?

• Active sub-groups• Round robins compulsory• Good illustrations, graphics

Is it worth it ?

Of course it is

?

Market impact

• EN 927-series implemented

• Marketing aspects

• Quality aspects

Research needs

• Moisture balance

• Durability