Site work instructions

Section 3 - Substrates

SW 3.01 Concrete Floors - Moisture

It is important to ensure that the floor has an effective damp-proof membrane, no damp problems and a relative humidity in equilibrium with the surface of 75%. A small sheet of polythene left overnight and sealed flat to the surface will often give an indication that there is any moisture present - this test is indicative and not a guarantee that the substrate is dry.

SW 3.02 Concrete Floors - Dry in Depth

Do not use on substrates that have not fully dried. e.g. New concrete floors may take up to 12 months to dry in depth depending on method of construction and depth of concrete. A relative humidity in equilibrium with the surface of 75% is required before any painting can be commenced.

SW 3.03 Concrete Floors - Air Flow & Humidity

In order to dry correctly, the coatings (especially waterbased types) require good air flow at temperatures above 10 degrees centigrade with a relative humidity below 85%. Do not recoat or use the floor until the coating is fully dry.

SW 3.04 Concrete Floors - Unsuitable areas for use

Some floor paint systems are not suitable for externals or areas subjected to prolonged contact with wet vehicle tyres. We therefore recommend that if you are in any doubt, you should contact Dulux Trade Technical Advice Centre, ICI Paints, Wexham Road, Slough, Berkshire SL2 5DS. Tel: 08444 817 818 for guidance.

SW 3.05 Concrete Floors - Power Floated Concrete

Power-floated concrete creates adhesion difficulties and therefore should not be painted without successful preparatory treatment. This can be done by either shot blasting, grinding or using a floor etchant, to the manufacturer’s recommendations. Shot blasting is the most successful treatment and should be considered where the concrete is particularly well polished; it can also often be more economic on large areas.

SW 3.10 Walls - Areas of use

The systems for Walls and Ceilings are suitable for Internal Plaster, Render, Block, Approved Brick and Concrete, Plasterboards, Paperfaced boards, Cement boards, Calcium Silicate boards and Fibre Insulation type boards and External Render, Pebbledash, Tyrolean, Block, Approved Brick, Concrete, Cement Boards and Calcium Silicate Boards

SW 3.11 Walls - Cleaning & Repairing

See BS 8221:2000 Code of Practice for Cleaning and Surface Repair of Buildings (or as amended). This gives guidance on cleaning natural stones, brick, terracotta and concrete.

SW 3.12 Walls - External Wall Repairs

Building repairs should be carried out in advance of the start of the painting contract. See Clause SW 2.05 for further information.

All loose, hollow or defective rendering should be hacked off, and all large cracks cut out and defective or spalling bricks and concrete repaired and renewed with a suitable/matching material. All loose and defective pointing should be raked out and the surface brushed down to remove all dust and sandy material. The cleaned surface should then be prepared as appropriate and repoint with a suitable material. Allow to dry out completely. Remove any salts, loose sand or aggregate etc and *dust off. Cut out and make good cracks, holes and other imperfections with cement and sand and allow to dry out completely.

*When rubbing down dry and/or dusting off wear a suitable face mask to prevent the inhalation of dust. See SW 4.20 for further information.

SW 3.20 Wallcoverings - Surface

All paintable wallcoverings must be firmly adhering to the surface and be free from paste on the face side before painting.

SW 3.21 Wallcoverings - Standard Types for Painting

Lining papers, Woodchips, Glassfibre Wallcoverings, Duplex Embossed and High or Low Relief - type papers are purposely made for painting and can generally be painted with conventional emulsion type paints.

SW 3.22 Wallcoverings - Blown Vinyls

Blown Vinyl's can sometimes be painted but will normally require a first coat of a Matt Vinyl emulsion.

SW 3.23 Wallcoverings - Pulp Type

Pulp papers generally can be painted provided the inks do not cause staining.

SW 3.24 Wallcoverings - Putty/Hessian Type

Putty - type wallcoverings need to be basecoated with an oil based paint, normally Eggshell.

Hessians can be painted with conventional emulsion type paints but this can look unsightly as it tends to raise the fibres.

SW 3.25 Wallcoverings - Unsuitable Types for painting

Vinyls, Washables, Silks, Handprints, Flocks, Metallics, etc. generally should not be painted.

Previously painted wallcoverings are suitable for repainting with a similar type of paint provided the paper has been successfully painted before.

SW 3.26 Wallcoverings - Shaded

All wallcoverings must be shaded before hanging and used in accordance with the specific wallcovering manufacturer’s instructions.

SW 3.30 Wood - Areas of use

The systems detailed are for Professional use only and are in two groups of Wood; Landscape & Garden Timber and Joinery which can be Non-Resinous Softwood, Plywood, Hardwood, MDF, Approved Wood Building Boards etc.

SW 3.31 Wood - Resin & Knots

When encountering knots and resinous areas to be painted, apply two thin coats of 'Dulux' Trade Knotting Solution and allow to harden.

SW 3.32 Wood - Arrises

Prior to commencement of work to any window or item of joinery, the contractor may be requested to carry out an inspection of arrises. Allowance will be deemed to have been made within the tender sum for arrises to be created which comply with B.S.6150 Section 2 / 5 (Design, Specification and Organisation) or as amended:- a radius of 1 mm to 2 mm for timber other than sills and thresholds; sills and thresholds might need a 3 mm rounding.
*When rubbing down dry and/or dusting off wear a suitable face mask to avoid the inhalation of dust. See SW 4.20 for further information.

SW 3.33 Wood - High Risk Joinery Sections

Where instructed to do so, in all cases, completely remove all coatings from sills, lower horizontal members of frames and sashes, adjacent vertical rails to the height of 150 mm, and all weatherbars to doors. For all defective areas, other than those mentioned above, the entire member or section must be stripped back to the nearest joint.

SW 3.34 Wood - Dimensional Stability

Dimensional stability is a key requirement for doors and windows. Low build stains are therefore not recommended for use on these substrates.

SW 3.35 Wood - Failed Joinery Sections

Where instructed to do so, use the appropriate Repair Method from the Window Care Systems document "A Guide to Specifying Pre-Paint Repairs." See Clause SW 1.04 for further information.

SW 3.36 Wood - Building Repairs / Replacement of Decayed Timber

Building repairs and the replacement of decayed timber with suitably preservative treated wood should be carried out in advance of the start of the painting contract. See Clause SW 2.05 for further information. Surfaces should then be allowed to dry out completely before painting.

SW 3.37 Wood - Denatured Woodwork

Failure to remove denatured wood before painting is a common cause of premature paint failure. Ensure that all denatured wood is completely removed by *manual abrasion or by power sanding to produce new clean sound wood.
*When rubbing down dry and/or dusting off wear a suitable face mask to avoid the inhalation of dust. (See SW 4.20 for further information.)

SW 3.50 Metals - Complexity

The complexity of Metal as a Substrate is clearly illustrated on the Condition of Previous Coating Table v2 (see Appendix 1). It can be notoriously difficult to identify specific types of metal and, very often, the type of specialist coatings which are commonly used. We therefore recommend that if you are in any doubt, you should contact Dulux Trade Technical Advice Centre, ICI Paints, Wexham Road, Slough, Berkshire SL2 5DS. Tel: 08444 817 818 for guidance.

SW 3.60 Plastics - Type of Substrate

There are many grades of plastics, not all of which can be painted. We therefore recommend that if you are in any doubt, you should contact Dulux Trade Technical Advice Centre, ICI Paints, Wexham Road, Slough, Berkshire SL2 5DS. Tel: 08444 817 818 for guidance.

SW 3.61 Plastics - Pipes & Gutters

The plastic most commonly found in the Building Industry is in the form of plastic gutters and pipes. The surface is generally intended to be self- finished and so maintenance free. (See BS 6150:2006 Section 38 Plastics, or as amended, for further information).

SW 3.62 Plastics - Type of Plastics

Some plastics systems are suitable for ABS and UPVC (plastic fittings and pipes) but refer to BS 6150:2006 Section 38 Plastics, or as amended, for further guidance regarding suitability.

SW 3.70 Problem Surfaces - Areas of use

The systems quoted for Problem Surfaces are suitable for substrates such as Ceramic Wall Tiles, Laminates, Melamine, Glass, Anodised Aluminium, *Approved Grades of Powder - Coated Steel, and Stove Enamelled surfaces etc.
* (some contain silicone oils to make them self cleaning and this could affect performance.)

See also