We installed these balau wooden screens in Umhlanga in Durban in early 2018. The brief was to provide some privacy to the upstairs verandah. There was originally a glass balustrade on this verandah and being at the end of a cul-de-sac this property’s verandah was very visible to vehicles and people driving or walking to the end of this cul-de-sac.
We removed the glass balustrade to make way for the wooden balau privacy screens. A balau structure was first installed fixing 40 x 60 vertical posts to the top side of the lower slab and the underside of the top slab to provide a frame on to which we screwed our horizontal balau slats.
When installing screens it is quite common to use different sized slats as we did here. Balau deck boards normally come in two different sizes being 19 x 68mm and 19 x 90mm. 19mm is sufficient thickness for screens and then one can mix the width by using a 68mm board and then a 90mm board. One can also rip a 68mm in half leaving 30mm and use that as well to create a visually appealing screen with differing widths of boards.
Gaps between these boards should ideally be 19mm to allow for wind loading. Obviously the closer the boards the less wind can penetrate the screen thereby increasing the wind loading on the screen. A gap bigger than 19mm results in too large a gap and privacy is sacrificed.
Sufficient vertical supports should be provided for stability and integrity and they should be close enough together so that the boards don’t bow between supports. Balau can normally be spanned about 600mm to 1m between supports to sufficiently pull each board straight to reduce bowing. At times a “strap” can be installed behind the boards to pull them all straight.
It is often a lot cheaper, and just as effective, to use a correctly treated pine structure to fix these boards to. However with a 19mm gap and visibility of the structure as well as visibility from behind, we prefer to use a balau structure. In this instance we used a 40 x 60 balau solid piece from top to bottom which worked well.
These screens can be oiled or left to grey naturally. Either way the life span of the wood is not increased that much be oiling them as balau contains natural toxins which limit insect infestation and oils and resins which repel water and limit rot. If they are to be sealed then an oil is the right way to go. Any other coating that dries on the surface of the wood will eventually peel and flake which will be costly to remove and re-coat.
For a no obligation quote on your timber decking, screens, pergolas etc. please contact us on 082 496 5444 or use the contact form below.