10 hints to help paint the roof

Press, 14 March 1985, Page 28

10 hints to help paint the roof

(By PHIL ROBINSON, technical manager. Samson Gold-X Coatings)

Whether it is the roof of your house, family bach, or factory that you intend painting you will want a finish that locks good and is going to last for years. The key to a top-quality job is careful preparation before painting starts. The roof surface must be clean and free from mould, lichen and calling cards from passing seagulls. Red rust patches require spot-treat-

Mould or lichen should be removed, and the cleaned area treated with an antimould preparation such as anti-mould and bactericide to kill all the spores. Even new iron requires cleaning to remove the oil coating from the surface.

The best general clean-up for a roof is wire brushing to remove loose paint followed by a good scrub with detergent and water, using a stiff broom and finally a rinse down with the hose.

Bare patches of metal and new galvanised iron roofs require priming with an acrylic galvanised iron primer.

Forget the old rule of letting new roofs weather before painting. It has been proved that this reduces the life of the galvanising layer, especially if you live near an industrial area or close to the sea.

If you have to replace sheets of iron, remember to prime the backs of the laps too.

Of course, fibre-cement and concrete roofs will not need the primer coat since they do not corrode like iron. The 10 handy hints:

1. Talk to your paint supplier before beginning the project For information such as suitability of the paint for collecting’ drinking water, what primers ant: topcoats are available, and what colours are available, the experts are always the first port of call 2. Make sure your roof will last as long as the paint on it Be prepared for small repair jobs while painting. A hammer and a handful of lead-head nails should accompany your inspection of the roof so you can replace weak nails before you begin. 3. Be careful of electricity. Contact your power board and arrange to make safe any lines running close to your roof. 4. Always wear non-slip soft-soled footwear on the roof. Bare feet leave invisible greasy footprints, and can be quite unpleasant on a hot roof, and hard-soled shoes damage the roof surface. Remember to walk along the lines of fixing nails otherwise the iron may bend. 5. If your roof has a steep pitch, either use a ladder which hooks over the ridge or rig up safety lines. This may sound overcautious but why take risks? Even on a single storey house there is

If on a hot day polythene (alkathene) pipe is laid in a trench without sufficient spare length to allow for contraction, and the soil is back filled, the pipe may either break by contraction, or pull off the fitting at one ent). Six metres of polythene may contract more than 5.7 cm under New Zealand climatic conditions.

Do glue treated timber within eight hours of machining. The small amount of treatment salts which form on the surfaces when timber is left longer than eight hours will effect the bond between the laminated timber joints.

no guarantee that you will fall on your feet 6. Do not paint the roof in weather extremes. If the temperature of the roof will drop below lOdeg C or rise above SOdec C during the half hour it takes for paint to set up, you should cease painting. With roof enamels, painting too late in the day can give problems if a dew falls at sunset

7. Most paints are formulated to be applied by brush. While brushing is almost old fashioned and may be a little slower, it is still the best method of ensure a full even coating.

8. Remember that two coats of finishing paint will last three times longer than one.

9. In case you are confused, acrylics' can go over any other paints, but enamels are best used over existing enamels only. 10. The manufacturers have formulated the paint specifically for the root Make sure you: Take time to read the instructions on the can before you begin painting — amazingly few people do. If you have the wrong paint, it is easier to remedy before you begin than after you have finished.