The fungus mould growth on exterior weatherboarding can be a costly business for it means the walls need repainting far earlier than they would under normal wear. Much can be done to check the growth of this fungus from the start and so eliminate early repainting.

B.A.L.M. have issued a specification showing the correct methods for exterior paint application and with it they emphasise that both 87 Line Undercoat and Dulux House paint have been formulated to provide surfaces highly resistant to infestation with mould growths.

That surely, is the answer to the trouble: to avoid it from the beginning. However, the specifications given here show the treatment they advise if the walls already show discolouration from mould growths.

Exterior Painting Specifications
Dulux Hi-Gloss House Paint—87 Line

A. New Woodwork—Excluding Totara

• Operation 1: Prime with one brush coat, of B.A.L.M. Primer for Dulux Hi-Gloss Paint on B.A.L.M. Pink Primer P.T.I. Allow 24 hours to dry.
• Operation 2: Brush one coat of B.A.L.M. Undercoat for Dulux Hi-Gloss Paint. Allow 24 hours to dry.
• Operation 3: Repeat Operation 2.
• Operation 4: Brush one coat of Dulux Hi-Gloss Paint 87 Line as received in the container.

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B. Finishing of Totara

• Operation 1: Prime with B.A.L.M. Totara Primer, Reference Number 126.8752, and allow to dry at least 24 hours before recoating.
• Operation 2: Brush one coat Dulux Undercoat for Dulux Hi-Gloss House Paint. Allow to dry 24 hours before recoating.
• Operation 3: Brush one coat Dulux House Paint 87 Line, as received in the container.

N.B.: Whereas a three-coat specification is detailed above, it is recommended that a second coat of Dulux Undercoat 90 Line be applied prior to the application of the finishing coat. This is particularly recommended where undue time may elapse from the priming to the undercoating stage.

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C. Repainting over Old Paint Surfaces in Reasonable Condition

• Operation 1: Thoroughly clean down job, sanding where necessary to remove ingrained dirt.
• Operation 2: Brush one coat B.A.L.M. Undercoat for Dulux Hi-Gloss Paint. Allow to dry 24 hours before recoating.

N.B.: Depending on the porosity of the old surface, it may be advisable to reduce the undercoat with up to ¼ gal. of Linseed Oil per gallon.

• Operation 3: Brush one coat Dulux Hi-Gloss House Paint 87 Line as received in the container.

D. Repainting over Old Paint Surfaces in Badly Weathered Condition

• Operation 1: Clean down thoroughly by sanding, wire brushing and burning off where necessary.
• Operations 2, 3, and 4: As for Operations 1, 2, and 3 for New Woodwork.

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E. Repainting over Old Paint Surfaces Discoloured by Mould Growths

• Operation 1: Kill all mould growths by brushing on the surface a liberal coating of one of the following solutions:

  (a)	“Santabrite” solution (1lb to 5 gallons of water).
  (b)	Shirlan W.S. solution (1lb to 5 gallons of water).

  Allow to dry out thoroughly, and prepare job by brushing down and sanding where necessary.
• Operation 2: Brush one coat B.A.L.M. Undercoat for Dulux Hi-Gloss Paint and allow 24 hours before recoating.
• Operation 3: If surface is badly discoloured, repeat Operation 2.
• Operation 4: Brush Dulux Hi-Gloss Paint as received in the container.

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Any additional information on this subject, or any other paint problem will be gladly supplied if enquiries are sent to: The Technical Service Dept., The British Australian Lead Manufacturers (N.Z.) Ltd., Lower Hutt.