Exterior Decorating: Painting External Walls and Woodwork
The chief reason for coating exterior surfaces is to protect them against sun, rain and wind, and all the materials used for outside work should be of very good quality so that they perform their function properly. It is false economy to use poor quality materials for exterior work, especially when the cost of repairing or replacing damaged timbers and metalwork, which will deteriorate if not adequately protected, is taken into account. The manufacture of modern decorative materials is such that maximum protection can be afforded to surfaces, at the same time creating an attractive scheme of decoration. All the paints used for exterior work should be of outside quality. The job of decorating exteriors should be done in sensible sequence by coating top surfaces before treating lower surfaces. Exterior decorating has an advantage over decorating interiors in that the work can be divided into smaller sections, each one of which may be completed separately.
The tools and equipment used for exterior decorating are the same as those used for interior work with the addition of one extra piece of equipment — a ladder. For most modern homes a 24-ft. Extending ladder will be found sufficient; the advantage of using an extending ladder is that the two sections may be taken apart and used separately. In some localities it is possible to hire ladders from local builders’ merchants, but if you are considering the complete maintenance of the exterior, and intend doing this work regularly, it is advisable to invest in the purchase of a ladder.
The sequence of exterior decorating is very much the same as the order in which interior work is done. Any alterations and necessary repairs should be carried out before preparing the outside surfaces for redecoration, and the work is commenced at the top of the house and continued downwards as progress is made. The first surfaces for exterior decorating are those of, eaves boards and fascia boards; this is followed by decorating the top sections of downpipes and windows of the upper floor and completing the job with the decorating surfaces of lower floors. This does not mean that each section, into which the work is broken down, should be completed by the application of all coats of paint before the next section is commenced. Each coat should be applied to all the surfaces, in top-to-toe sequence, before applying the next coat in the same order.
If any wall surfaces are to be treated with distemper, or emulsion paint, this is best done after the woodwork and metal surfaces have been primed and undercoated and before finishing coats are applied. It may be found, especially in the case of modern homes, that the outside surfaces of down-pipes have been coated with a bituminous paint. Ordinary paints cannot be easily applied over bituminized surfaces; if this is done the bitumen will burn through and stain the new paint. Any metalwork parts that have been coated with a bituminous-based paint should first be sealed by the application of a coat of aluminium priming paint, or knotting-quality shellac. The insides of gutters should be cleaned out with a stiff brush to remove all dust, dried sediment, leaves and birds’ nests. Any rusted parts inside gutters should be vigorously attacked with a wire brush until the metal is bright and gleaming. Inside surfaces of gutters should then be finished with two coats of lead paint. It is not necessary to apply finishing paint to the inside of gutters.
Although the work of exterior decorating may be broken down into small sections of work, any surfaces bared in preparation should not be left without recoating them. If this is done any rain or damp weather between treatment of the sections will attack the bared surfaces. Paint should never be applied on damp surfaces; although paint may appear to go on quite well over surfaces that are damp, the life of the new coating will be considerably reduced, and shortly after painting the new paintwork will flake and crumble. The blistering of paint on outside surfaces is due to two main causes. One is excess moisture in the wood under the paint, which turns into steam and expands to form blisters after periods of strong sunshine. Another reason for blistering is due to wood with a high resin content from which resin exudes following long sunny periods.
If outside surfaces are in very bad condition it may be necessary to remove the paint by softening it with a blowlamp and scraping the softened paint from the wood with a stripping knife or shave-hook. It should be appreciated that a blowlamp should not be used for cleaning surfaces unless the old paintwork is badly blistered and scored and is generally in a very poor condition. Butane blowlamps will be found quite easy to use by the handyman for burning off outside surfaces. There are, however, some factors governing the use of these appliances which must be taken into account when using them. It is only necessary to apply the flame of the blowlamp to the woodwork for a very short period to soften the paint, and only a small section of the job should be burnt and stripped at one go.
Over-enthusiastic use of a blowlamp may char the wood, especially at the edges of window-frames and mouldings. Also, if a blowlamp is held too long near window glass, the glass will crack, especially in cold weather. To appreciate the extent of this danger, the inexperienced handyman wishing to use a blowlamp will find it advisable to hold the flame against a piece of scrap glass; this will give some idea how long the flame can be played on the glass, or near it, before cracking it. When burning off windows it is not necessary to soften the paint on the putties and, as far as possible, the flame of the blowlamp should be kept well away from glass.
Any woodwork that has been bared by stripping it, and any new wood that has been used for repairing outside surfaces, should be knotted and primed before being undercoated. If outside surfaces are not in too bad a condition the use of a blowlamp may not be necessary, and the wood should be prepared for repainting by vigorously rubbing down with grade middle-two glass-paper. The glass-paper should be folded to enable it to be worked well into corners, and during all the work of exterior decorating frequent use should be made of the dusting-brush.
In all areas of home decorating, each separate coat of paint applied should be allowed to dry thoroughly before the next coat is brushed on. This is especially necessary with outside work and the decorator who wishes to attain a high degree of proficiency should take as much care when applying undercoats — perhaps even more — than finishing coats. No amount of care in applying finishing coats will result in a good job if the work of preparation or applying the undercoats has been skimped or hurried. As with interior work the brushes used for exterior decorating should be of a sensible size in relation to the surfaces being coated. Any spots of paint that are splashed or dropped on surfaces other than those being decorated, should be immediately wiped off with a turpsy rag, and not left to harden. This is particularly necessary in the case of splashes which drop on small projecting roof surfaces of lower floors, such as those over porches. Any hardened spots of paint on brickwork may be removed by rubbing the spot with a small piece of brick. The coats of paint should be brushed on and laid off in the same way as described for interior decorating.