Here’s another wooden deck we built in Kloof, Durban which is similar to one we built in Hawaan Forest estate a few years ago. It has a fire pit with a U Shaped bench which double up as steps around it. These steps were designed so that they were wide enough to sit around the fire and with a riser that is not too steep to climb.
The substructure or frame was the normal H3 and H4 CCA Treated S5 pine we use. All our decks are built with an S5, H3 and H4 treated pine substructure. S5 refers to the grade of pine which is commonly called industrial grade. It is graded as such based on the number of knots per square metre. S5 is SABS industrial grade and has been passed by SABS to be used in construction. It doesn’t however make a very good deck board as there are too many knots which are not only unsightly but also they can become dislodged leaving a hole in the deck board. H3 and H4 CCA Treated refers to the hazard classification of the treatment as set out by The Wood Preservers Association of South Africa. Each H classification has a specific application and provided the correct H classified timber is used, the life span of the timber can be many more than 50 years.
The deck boards that went on top of the substructure were 19 x 68mm yellow balau deck boards. The other option for deck boards is 19 x 90mm yellow balau deck boards but they do carry a surcharge as they cost more per square metre than the 68mm wide boards.
There are two types of balau readily available in South Africa. Yellow balau and red balau. Yellow balau is more common and is superior to red balau. What we are seeing in South Africa nowadays which is called red balau is a lot more porous and softer and as such will absorb more water and rot more quickly. We only stock and use yellow balau.
This project in Kloof also included a pergola. What we have found to be most cost effective in pergolas is to use a 90 x 90 square balau post, 30 x 215 balau beam and 30 x 102 balau purlins or trusses at about 600 centres. This spec gives the pergola enough timber to be attractive and serve its purpose whilst still keeping costs down. With this particular job we also installed extra battens on top of the purlins. We used 30 x 40 balau for this purpose which again keeps costs down whilst still providing enough timber to keep it looking good and to do it’s job. Other options for battens on pergolas are to use a 30mm wide strip of balau with a 30mm or 60mm gap between. This provides more shade but of course comes with a higher price tag because more timber is being used.
The timber was sanded and sealed with an oil based sealer we use which doesn’t dry on the surface of the wood so it cannot peel and flake. Unlike other coatings which dry on the surface. These tend to peel and flake.
For a free no obligation quote on your wooden deck, pergola, balustrade and stairs requirements please contact us on 082 496 5444 or use the contact us form below.
This was an interesting wooden pergola we built in Durban. Most often pergolas are built using planed all round pieces (PAR) in the traditional pergola design which is vertical posts to support the structure and horizontal purlins of varying width and thickness to cover the top. Wooden pergolas don’t really offer any functional benefit as the rain still comes through and it offers limited sun protection depending on the density of the purlins above. This one however offered both protection from rain and sun yet still allowed light to come through.
We built a structure using H3 CCA Pine which is guaranteed for 50 years against rot and insect infestation. On top of this we placed polycarbonate roof sheeting which we got from Modek. We used their bronze translucent one so that it breaks the sun yet still allows light through and of course offers protection from rain. It is best to use custom-made lengths so as to avoid any joins which would need to be waterproofed. It is not sufficient to overlap them in the direction of the fall. Because the angle or pitch of the roof sheeting is relatively gradual, the wind can blow the water backwards, up hill and through the joins. So it must be waterproofed to avoid any leaks. It is therefore much better to use one full length, the same length as the structure itself.
Once our roof sheeting was on we installed thatching laths beneath with no gaps between them. These laths vary in diameter from 20mm to 35mm. So one needs to install them head to toe to limit the size of the gaps between them. This way they become quite dense so that one can’t see the structure or roof sheeting from beneath, but they still allow enough light through. In other jobs we have installed them with as little as half a laths diameter gap, but that still allows quite of lot of visible roof sheeting from beneath. It is therefore better to stack them tightly up against each other.
After these we clad the sides to cover or hide the pine we used with balau deck boards. The balau is a much better looking wood in terms of grain, colour and the straightness of each board. Balau is very stable and will tend to warp or cup less than pine over the years. So the appearance of the structure will remain flat and square a lot longer than pine.
Wooden pergola with thatching laths
The final product was a rustic looking pergola which offered protection from sun and rain yet still allowed natural light through. The client later installed a sound system and lights beneath. They had a pizza oven installed and a gas braai with a bar area which made for a very nice outdoors entertainment area which was protected from the elements.
For a free no obligation quote on pergolas or other decking needs as well as floors or laminates please contact us on 082 496 5444 or you can use the form below to e-mail me.