How to paint a concrete floor ( guide )
How to service a neglected swimming pool ( 10 steps )
How to cool a building without electricity ( demo )
How to repair and waterproof leaks and cracks ( guide )
Outside walls
Painting exterior walls is basically the same as painting any other surface; the major differences are in the scale. As with all painting, the quality and integrity of the finish depends to a large extent on the preparation of the surface before you even open a tin of paint. Also, the preparation differs slightly according to the finish over which you will be painting.
New brick
Concrete and cement rendering should be treated in the same way as new brick. To start with, remove any dust or loose material using a stiff brush, and scrape off any splashes of cement or concrete. Look out for any patches of white fluffy crystals; these are a result of efflorescence, and indicate that moisture is coming to the surface of the wall. If you paint over the patches, the moisture will tend to lift the paint off.
Clean the efflorescent debris off the walls with a stiff brush and wait about two weeks to make sure that no more patches emerge. Wash any mould growth or lichens with a proprietary mould inhibitor or bleach. Then scrape off these growths, and apply a further coat of inhibitor or bleach to the bare surface. Finally, make good deep cracks or holes in the surface using appropriate filler.
Where new, shuttered concrete is to be painted, it is important to degrease the surface because it may still have traces of the release oil used on the inside faces of the shuttering.
Previously painted surfaces
It is always advisable to prepare painted surfaces before repainting, and in the case of exterior work, it is essential if the new coatings are to protect the building in the way they are designed to.
Oil painted surfaces: Wash with a strong cleaning agent, and then rinse with clean water. Scrape off any loose or flaking paint, make good any deep cracks and holes, and fill shallow cracks with suitable exterior filler.
Emulsion painted surfaces: Wash with a detergent, and then rinse with clean water – anything stronger will damage the emulsioned surface. Where water penetrates the surface, allow it to dry completely before you start painting. Again, scrape off loose flaking paint and then repair cracks.
Damp surfaces
Walls that display signs of either damp or mould growth must be treated before you can paint them. Where surfaces are prone to damp, such as basement walls or garden walls, you must apply a coat of bituminous emulsion sealer and allow it to dry thoroughly.
Mould-infected surfaces
Mould growths are common on exterior surfaces where moisture is present as a result of the atmosphere, structural faults or defective plumbing. To remove them, first brush a coat of proprietary mould inhibitor on to the infected areas, and then strip all the mould back with a stiff brush and scraper. Do not use a wire brush, however, as any material particles left behind can cause rust stains.
Then apply a second coat of mold inhibitor to the surface and allow it to dry. These solutions contain strong fungicides and you must wear rubber gloves and goggles when dealing with them to guard against splashes. This process must be carried out before any sealer is applied to the surface of the wall.
Painting
Try to plan exterior painting for warm, dry days. Extreme cold or frost can affect the water content of the paint, causing a complete breakdown in the film. Rain on the surface before the paint is dry can thin it disastrously. The first coat on porous surfaces can be thinned according to the manufacturers instructions. But, be sure not to over-thin; the result will be poor opacity and the need for extra coats.
Charge the brush or roller with plenty of paint, and lay it or roll it in all directions. Do not apply the material too far, however, because correct covering and protection requires that it be twice as thick as ordinary liquid paints. Any spots and splashes must be washed off immediately with water because exterior grade paint sets rapidly.
During short breaks, wrap the brush or roller tightly in a plastic bag to prevent the air curing the material. Do not be tempted to leave it in water because the initial application will be patchy. When you have completed a session of work, immediately clean all the equipment. – “Antonella Dési”
The pros and cons of a thatch roof
The kind of grass
Generally, finer grasses are the best for thatching, as long as the stem is less than four millimetres in diameter, as the thicker stemmed grasses are not suitable for thatching. The finer grass from KwaZulu-Natal is preferred over the slightly thicker stemmed grasses from the Highveld. The grass has to be dry and must have lost all its seed when it is harvested for thatching. The best time for collecting thatching grass is in winter when it is bone dry.
If you have opted for a thatch roof, it is important to ensure that you are not building near to or under any trees. If the thatch gets wet, it needs to dry out as soon as possible to prevent rot or fungal growth. If surrounding trees keep the roof in the shade for most of the day, the grass will have a much shorter lifespan than those in the full sun. The leaves from the surrounding trees will also drop onto the roof and keep it damp for even longer, which will also lead to rotting.
Thatch that is well laid and found in very cold winter climates can last very much longer, because during the winter months the thatch actually freezes and all insect and fungal life found therein consequently dies. Believe it or not, thatch is also protected by sea spray as the salt sterilises the grass and its contents.
If the roof is properly laid and the right grass is used the average thatch roof can last for approximately 25 years, however, in the right climatic conditions, it would be able to last for up to 30 years.
Pros and cons
Thatch is the best insulated roofing available to man. Most other roofs need to be insulated after they have been installed, while thatch roofs automatically offer excellent insulating properties, making it ideal for our hot local climate to keep the interiors of our homes cool in summer and warm in winter.
If thatch is well laid, it will be virtually maintenance free. Thatch is very vulnerable to being stripped by birds, especially weavers that can really destroy a roof within a year. If you need to protect your thatch, it is wise to cover it with a plastic mesh that will keep the birds away. Wire mesh can also be used, however, in time it will rust.
The weakest point of any thatch roof is the ridge. One can get it covered with a fibreglass hood or the old method of mortar will also do the trick. Ensure that the apex is always kept in good condition and that it remains completely watertight at all times. This is the most vulnerable part of a thatch roof and needs to be constantly maintained. If any work needs to be done on the thatch, always use an experienced thatcher, and do not allow any workmen to move around on the thatch, unless completely necessary.
Protecting your thatch
All houses with thatch roofs need to have lightning conductors installed to protect them from being struck by lightning and consequently burning down. These conductors need to be in accordance with the SABS Code of practice. If the house is very high or large, the mast would have to be very high to cover the whole area. This can be solved by putting in two masts or even a spike can be installed on the chimney to cover the area not covered by the spike.
Accredited thatch fire retardant
Learn about the history of thatch
Roofs
It is not always your agenda in the dry months to give your roof a good inspection, but it is a must-do and should become an annual habit. Once the rain starts and your home is leaking, it is usually not possible to fix the leak until the rain has stopped, and by then the water damage could be quite considerable. So it is wise to give your roof a thorough inspection before the rainy season begins.
Fix a leaking roof fast
Different roofs – different problems
No matter what type of roof you have protecting your home, they all need to be checked and regularly maintained because normal wear and exposure to the elements dictates so.
Flat roofs
Most flat roofs are made from concrete or corrugated iron. If the roofs are built inside parapet walls, the gutters need to be checked often before and during the rainy season for leaves and any other debris that could cause them to block and overflow.
If the down pipes get full of leaves, the gutters will fill up and the water will spill over and run into the house down the interior wall located under the gutter. This kind of water leak can cause maximum damage and it is the easiest to prevent. If your flat roof is made of concrete, make sure the sealer used is not pealing or cracking as this too can lead to water leakage and damage. Ensure all drains are free of debris that could cause any blockages.
Pitched roofs
Your pitched roofs can be covered in all sorts of materials, including thatch, corrugated iron, and a wide variety of different tiles. Ridge tiles, roof valleys and flashings are all prime leak weak spots. Go around the roof and check that all the flashing is still in place and well sealed with waterproofing membrane. Sometimes extreme hot or cold conditions can cause the membrane to pull away from the flashing and if left untreated, this will lead to leaking. Thatch roofs need to have regular inspections by a professional, as they can be dangerous to climb onto.
Check the roof for broken tiles and replace them. Make sure all the ridge tiles are secure and held together by cement and sealer. It is better to be over cautious, than pay the high price of fixing water damage. in cases where nails are used to secure your roof covering ensure that the holes left behind from missing nails are sealed up. In a big storm, a small nail hole could lead to serious water damage on your ceilings.
If you live in an area that gets hail storms, take special care with your gutters. After a particularly severe hailstorm, homeowners should get up onto the roof and clear them out, as hail can causes the down pipes to block. Most builders would have installed larger than normal gutters and down pipes to handle this problem, but if you get a leak every time you have a hailstorm, it would be prudent to increase the size of both your box gutter and down pipe.
Chimneys
Your chimney is very often a major culprit of leaks – very often the structure is solid, but the cowling at the top of the chimney is not sufficient to stop the rain from getting in during a windy storm. If this is not sorted out, the entire metal casing of your fireplace will eventually rust away. Also check the seals between the roof and the actual chimney as the heat generated by the fire can very often cause the seal to peel away or crack.
If you just do these few simple checks before the rainy season, you should be able to prevent any leaks and have a dry and undamaged home. Most leaks can be sorted out by you before they get too serious and end up causing a lot of damage. – Antonella Desi
Cosmo-Dec Everlasting Coatings originated in 1991, with a single product – Therma-Masta™.
Knowledge gained from manufacturing this complex and unique product allowed us to formulate new and innovative products such as Fire-Guard™, Aqua-Mite™, Aqua-Therm™, Clean-Air, etc. for specialty applications.
To-day, 3 decades on we manufacture more than 80 different types of construction chemicals out of our factory in Pretoria, Gauteng.
