Terracotta Roof Tiles generally only need a clean and re-pointing, a clear sealer can be used to bring out the existing colour.

HOW TO PAINT A ROOF

Painting a roof can vary slightly depending on what material your roof is made of but there is one thing they all have in common and that is they must be cleaned before you apply any paint.

How To Clean A Roof

Depending on your budget and what you have available to you will depend on how you clean your roof. Using a high pressure water blaster is one of the best ways to clean a roof, specially any roof with a rough surface. You can use a broom and hose but you will need some type of chemical to help remove the mould from within the pores of the surface. This is where high pressure is good, it does get into all those nooks and crannies

A roof with a smooth surface such as galvanised iron could be washed much easier with a boom, some detergent and a hose to wash it off after. High pressure is also good to use but it is not as important to use on smooth surfaces.

How To Paint A Corrugated Iron Roof

If you are painting a new iron roof you will need to wash it with a degreaser before you start unless the roof is more then a year old and has weathered. This means that the oil from fabrication has worn away and the iron has been slightly etched through weathering.

With unpainted iron you will need to prime it first with a suitable primer, this is also the case for any sheets of iron that may have been replaced on an existing roof.

You will need to apply two coats of suitable paint, and the choice of colour is up to you but do remember lighter colours will reflect the heat and darker colours absorb the heat.

Airless spraying is the quickest way to paint any roof and if you decide to paint your roof this way there is a technique to applying the paint. When you are spraying you should spray about a metre wide section and work your way down the sheet, spray in the direction of the flutes in the iron. If you like you can use the joins in the iron as a guide, it is an easy way to tell exactly were you are at. Once you have worked your way down the sheet and completed that section move back to the top of the roof and repeat for next sheet of iron. You must keep a wet edge at all times and that is why you go back to the top of the roof before it starts to dry, if you decide to work back from the bottom to the top, the top part could have tacked off when you get back up there.

You can buy rollers that are shaped like corrugated iron and they do work well, but you will still need to cut in all the corners and ridge caps. With some roofs you may need to run the brush down the join in the sheets as some times they are slightly raised and the roller will not get this area.

Now if you are really keen you could brush the complete roof, I have done it in the past but that was before I got my first airless spray gun. If you decide to do it this way there are a few things to remember , start early in the morning and don't try to paint in the heat of the day, the paint will dry far too quick. The other thing to remember is to work in small sections, simular to spraying but maybe only half a sheet width at a time and make the over lap mark in the hollow of the iron and not on the top of the ridge.

How To Paint A Tiled Roof

Generally when you are painting a tiled or shingle roof is because all the existing glaze has worn off and the roof is looking a bit shabby. Some roofs will look better than you think once the cleaning has been done, I have cleaned a roof and the customer decide not to painted it as it looked almost band new.

With tiled roofs there is an issue with ridge capping, they may need to be fixed before you start painting and it is generally referred to as pointing and bedding of ridge caps. Most will need re-pointing and some may need re-bedding, with re-bedding they take off the ridge cap and re-bed it in a new mix of mortar. Pointing is where the ridge cap is not moved but the outer mortar is repaired generally with another layer of mortar applied over existing. If you have had any repairs like this done after you have cleaned the roof make sure you use your garden hose and give the roof a final clean, some times just a broom will do the trick.

If your roof looks really bad and just about all the colour has gone then you will need to sealer the roof first, most roof sealers/primers dry clear. Make sure you apply plenty, you will need to give the roof a good coating to give it a chance to soak into the tile.

As with any roof you will need to apply two coats of suitable paint, and the choice of colour is up to you but do remember darker colours absorb the heat while light colour reflect the heat.

Airless spraying is the best way and the quickest way to paint a tiled roof and there is a technique for painting these types of roofs. With tiled roofs the best way to spray them is to paint about 4 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 4 tiles down again then continuing across the roof to the other end. Each time you start another section paint up to the bottom edge of the previous tile painted, this will help avoid over lap marks.

You could paint a tiled roof with a brush but it would take a long time to do, so unless you have plenty of time to spare I would suggest hiring an airless spray gun, it will cost you a few dollars to hire but the time you save will be well worth it.

Roof Painting Tips

When painting a roof make sure you are able to get back down from the roof with out having to walk over wet paint, this can be avoided with a little planning before you start.

If you are going to use an airless spray gun to paint the roof try to avoid painting on a windy day, there is always some over spray and it can be carried a long way in windy conditions. A friend of mine recently painted a large two storey roof and had the task to knock on some ones door to let them know their Harley Davison was cover with paint spots, not some thing I would want to do. So do take care when using an airless spray gun in windy conditions.

Check the weather forecast, you don't want to paint your roof if its going to rain and if it is going to be hot I would suggest you start early.

Roof Paint

There are a few choices when it comes to roofing paint and you will need to decide what is best for you and also how much you are willing to spend.

Water based roofing paints would be the preferred paint used for cement tiled roofs and shingle roofs but there are some paints on the market that are not suitable for drinking water. So if you do collect rain water from your roof do some research and ask before you purchase your paint if the paint is suitable for the collection of rain water.

Oil based roofing paints are best suited for collecting rain water but I wouldn't paint cement tiles with oil based paint. Oil based roofing paints are best suited to iron roofs, if the roof is old and rusty it will help keep the rust at bay. Water based paints can be used on iron roofs but I would make sure any rust is treated well or it may appear again soon after painting.

If you have a few extra dollars to spare you could think about getting either one of the heat resistant paints or get an additive to add to your paint. Thermal additives are available and I have heard some good reports about them, I will be using a thermal additive when I paint my roof mainly because I want to use a dark colour. I also know some one that painted a shipping container with a thermal paint and they were very happy with the result.