SA Affordable Housing November / December 2021 - Page 24


Using the correct system – and equipment – when painting a roof

Painting a roof may appear a simple task but it is important to follow essential guidelines to do a perfect job , says Tara Benn , executive director of the SA Paint Manufacturing Association ( SAPMA ).

Tara says the first step in painting a corrugated / IBR iron roof – or any roof for that matter – should be to thoroughly clean the roof . This could be done with a broom and hose but for best results she advocates the use of a high-pressure water blaster which provides maximum penetration of spots that are hard to access .

“ A new iron roof must be washed with a degreaser before painting starts . A galvanised iron cleaning type of solution for the removal of contaminants and possible oxidation layer is recommended . Such a cleaner would normally also help to key and etch the non-ferrous surface without damaging the zinc layer . Alternatively , a degreaser can be used in conjunction with large heavy-duty scour pads to provide the necessary key to promote long-term adhesion ,” Tara advises .
“ The galvanised iron roofs must first receive a suitable primer followed by two coats of paint . Colour is a personal choice but bear in mind that lighter colours will reflect the heat , providing a cooler interior .
“ Airless spraying is the quickest way to paint any roof , but this process calls for a certain technique when it comes to iron roofs . You should spray sections of about a metre in width and work your way down the sheets , spraying in the direction of the flutes on corrugated iron roofs . Once you have worked your way down , move back to the top of the roof and repeat the application on the next sheet . You must always keep a wet edge : that is why it is important to start painting the top of the roof before the paint starts to dry .
“ You can also use rollers shaped like corrugated iron but , although they work well , you will still have to make sure that the paint reaches all the corners and ridge caps . You could also use a simple brush to paint the entire roof , but it is a laborious task , and you have to start early in the morning to avoid painting in the heat of the day , particularly in summer when the paint will dry far too quickly . Another thing to remember is to paint in small sections - similar to spraying
– but with a brush , rather do half-sheet widths at a time . Also make the overlap mark the hollow of the corrugated iron and not the top of the ridge ,” Tara states .
“ For painting tiled roofs , a primer or roof sealer should be liberally applied followed by two coats of suitable paint . Here , also , airless spraying is recommended with the following technique : paint about four tiles down from the top , and then paint across the roof until you get to the other end . From there , go back to where you started and repeat spraying about four tiles down again . Then continue across the roof to the other end . Each time you start a section , paint up to the bottom edge of the previous tile painted . This system will help avoid visible overlaps .
“ You could also paint a tiled roof with a brush , but this really is a long and gruelling task . Rather hire an airless spray gun : the rental cost will be offset by the time saved ,” Tara concludes .
“ A new iron roof must be washed with a degreaser before painting starts .”
SAPMA recommends the use of an airless spray gun to save time and produce a better job when painting a roof .
22 NOVEMBER - DECEMBER 2021 SAAffordHousing saaffordablehousingmag SA Affordable Housing www . saaffordablehousing . co . za