Balau Wooden Deck, Kloof Durban







Balau pool deck and walkway – Kloof, Durban

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We engaged with Masslandscapes, a landscaper and garden designer (082 468 3759) on this balau pool deck project in Kloof, Durban to provide a solution for the client who wanted an area alongside their pool that they could utilise more. Before the project started there was the standard paved area of about 1m alongside the pool which was bordered by grass of about 1m and then a flower bed, before dropping down a small bank to the rest of the garden. The client wanted to increase the size of usable area alongside the pool.

Initial designs were to have a very similar layout as per the pics above with a semi-circle sort of node protruding over the bank to gain height and create a look out area overlooking the Kloof Gorge. This proved to be out of budget and would probably have resulted in doubling up sitting area as there was already a large tiled verandah extending out from the living area doors. The final design was settled on which is what you see in the pics.

We needed to excavate some of the garden down and move this top soil for use in another area of the garden. It is always recommended that sufficient space be left below the deck and below the bottom of the lower most bearer or joist to allow enough air flow to dissipate and evaporate any water that settles below the deck. Too often I have seen deck boards rotting prematurely due to insufficient space being left below. Water gets trapped below and the underside of the deck and structure remains damp. I normally recommend at least 150mm below the lowest point of the structure. Once we had enough space below we installed our structure using H3 CCA treated pine. Please see here for an article on the use of CCA Treated pine as structures for decks and balau as deck boards. All cut ends of treated pine, as a matter of course, are re treated with an approved end sealer. When a CCA treated piece of pine is cut it exposes a section that is not treated and can accelerate rot.

Post to ground are set in concrete and installed at the correct distance on the bearers to stop any bounce in the bearer and to provide enough support to prevent the bearer breaking. There are guidelines supplied by engineers for distances that these supports need to be installed. These posts need to be H4 CCA treated pine as they are in constant contact with wet soil.

A lot of this job involved lining up existing paving, pool copings, patio etc. to the deck so the lines were seamless and everything ties in neatly. A walkway, as can be seen from the pics, was created to run alongside the existing raised patio for access to the rest of the garden.

In finishing our decks we fill the screw holes with a clear epoxy mixed with saw dust to match the colour as closely as possible and then grind and sand it flat. Standard wood filler doesn’t quite do the trick and fails with exposure to weather. The filling of screw holes is a very important aspect of deck building. It prevents water sitting in the counter sunk screw hole which would then travel up the end grain of the balau and cause early rotting of the balau deck boards. We use a clear epoxy so that we can match the colour to the deck boards. Off the shelf epoxies are either grey or white in colour and don’t take the saw dust that well to match the colour. Also these epoxies dry very hard. It is better to use an epoxy that is semi pliable when dry. Through seasons of dry and wet, hot and cold, the inside diameter of the counter sunk screw hole will vary ever so slightly. If the epoxy has dried too hard it will cause it to pop out leaving a weak spot on the balau deck board. During maintenance intervals these should be checked and replaced if they have in fact popped.

The deck was oiled using a zero wax content product. The beauty of oil is that it soaks into the wood and therefore cannot peel and flake. A peeling deck is an expensive deck to maintain because you would need to sand off the coating completely to avoid a patchy finish when re-applying the coating. Whereas an oil simply degrades due to exposure to UV over time. A pressure wash and re-oil is all you need to do at maintenance intervals which is relatively inexpensive and easy to do as opposed to sanding the deck again. The oil also allows the natural beauty of the wood to shine through resulting in a more natural wood looking product. Coatings give them the effect of a painted deck especially over time when layer after layer has been applied.

For a free no obligation quote on your timber balau decking, walkways, pergolas and other outdoor timber products, please call us on 082 496 5444 or use the contact us form below. We operate throughout KZN.

Composite Deck Boards vs Hardwood Balau Decking

I’ve often been asked to quote, on or at least comment on, composite decking. Firstly we need to have a look at what composite deck boards are.

Composite deck boards are generally made from plastic and saw dust which can be anything from saw dust, wood chips to wood fibre pieces or bamboo. They can be either be new or recycled materials. One method of manufacturing composite deck boards is by extrusion. That is the materials are mixed together and forced through an opening to create a relatively consistent size and shape. Compression moulding is the other method used and consists of taking the combined liquid materials and compressing them under high pressure and heat into a mould to create the deck board.

Composite boards cannot be used as structural material as they do not have the required structural properties of, for instance, S5 SABS approved structural or industrial grade treated pine, or balau for that matter. As such the substructure of a deck still needs to be built using H3 CCA Treated pine. If the argument is that composite decks will last longer than solid timber, then half that argument is invalid because the structure is not made from composite materials. It is only the deck boards that are from composite materials and cannot “rot” in the traditional sense. However composites can fail if the process they underwent was not sound. There are various failures that can occur. A search on Google for “composite fails” will return many ways these boards can fail from a sub standard manufacturing process to fading in extreme direct sunlight, to warping, cupping or twisting due to heat from the harsh African sun.

Sustainability and “eco friendly” is often used as an argument in favour of composites. The balau and pine we use in decks is from sustainable forestry and is certified as such when imported or harvested locally. Producing composites also requires a lot of heat which is obtained from which source? So although composites can be made from recycled materials, one also needs to factor in the carbon foot print of making them, even though it is probably less than the carbon foot print of harvesting solid timber. Composites therefore do not carry a zero carbon foot print.

From a cost point of view composites are generally more expensive than balau. As with anything, you can get cheap or expensive and the risks of buying cheap composites speaks for itself. Some composites can be up to 4 times the price per square metre of balau. A cheap composite will tend to fail quicker as opposed to a more expensive one. If the cost of these boards is up to 4 times the price of balau then it stands to reason that  ALL the balau can be replaced up to 4 times before the cost becomes the same. It is highly unlikely that you will need to replace your deck surface four times in the life of the deck. What will commonly occur in a balau deck surface is that some boards will fail before others. Any failure of balau deck boards is normally long-term in any event. Deck boards are relatively easy to replace and relatively inexpensive. It is the structure that is expensive to replace and normally results in the whole deck having to be replaced. If our structures are both CCA treated pine in both types of deck, then the greater risk lies in the structure, not the boards.

The fixing system generally used to fix these boards to the pine substructure is a hidden screw of sorts and again there are various products available each one with it’s own advantages and disadvantages. A plastic clip is often used which is slotted into a groove routed along the edge of the board and then fixed to the bearer. Two boards often share a single clip which is then concealed below the deck board. So no screw holes through the face of the board. With the screw head being so small they can fail in that the screw can be screwed too far through the plastic clip. The clip itself is plastic and at certain temperatures will fail. The clip can only be guaranteed against failure below certain temperatures. In my opinion nothing replaces a Kalgard coated decking screw counter sunk through the face of a solid timber board to limit failure. In a balau deck, screw holes are filled with a clear epoxy and saw dust mixture so are not as visible as one would think once filled and sanded flat.

Scratches and fading in composites should be taken into account. A lot of manufacturers of composites guarantee a maximum percentage fade rate. How does one measure 10% fade? If a composite deck fades or gets scratched it can’t be sanded to remove these.

Maintenance of the deck is often used as an argument for using composites over balau. Water is largely drawn into wood through the end grain and not the face or side grain. Being balau it is naturally resistant to water ingression. If you take a 20 year old piece of good quality yellow balau and cross-cut it, you will most often find that no water has been absorbed through the board. Balau deck boards can be left un-oiled which will result in a grey appearance. Oiling or not oiling a deck won’t increase or decrease the life span of the deck by any material length of time. If oiled, maintenance is simple. Oil can be sprayed, brushed, wiped, sponged or even dipped. And oil won’t peel and flake. Coatings will. So it is quick and easy to maintain. If left un-oiled a pressure clean every 6 to 12 months is sufficient to keep your deck looking good.

Based on the above I am more concerned about the structure of a deck than the surface one uses. Structures are costly to replace. Deck boards are not. The above arguments for composites do not, in my opinion, warrant using them as opposed to balau.

We will however install a composite deck for you if you so wish, but I am not convinced that you will achieve the desired result by switching from solid timber to composites.

For a quote on your deck and other timber related structure please contact us using the contact us form below or call us on 082 496 5444.