Yearly Archives: 2013

Wooden Sundeck built in The Bluff Durban – Jan 2013

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sundecks durban

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After the last sundeck we built in Durban we were glad to have a small break. Temperatures reached about 38°C and even though we only had to sand and seal it, it was almost impossible to work in those conditions.

This next sundeck in Durban measured about 5.7m wide along the front of the house by 4m deep. It was on the first floor at a height of 3.2m above ground level. Due to the size we had to support it using 4 balau posts each of 90mm x 90mm in size and the other two ends of the beams were set in feet cut and anchored to the wall. Initially we were going to set the posts in concrete the normal 600mm deep. However the location was in the Bluff which is almost completely a sand dune. We dug to 1m deep in sand that had the same consistency as building sand, and could still stick a re-bar another metre into the ground. Instead of the normal 600 deep in concrete method we had to throw feet or pads of 1m x 1m x 200mm with re-bar set in the middle. This created a larger footprint and will prevent the posts from sinking over time. The re-bar ensures that the whole pad has to sink at the same time instead of cracking. The posts were then set on top of those with a re bar hammered into the bottom of the post and drilled into the concrete.  See the two pics alongside.

timber decks durban

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The posts are set as square to the wall as possible but there is no need to set them exactly square as they will simply support the beams and any difference won’t make a material effect structurally.

This deck needed 4 posts as the length was 5.7m and it is generally quite difficult to find beams in that size that long so they had to be joined in the middle with a post to support them. We were using 30 x 102 joists which can be spanned a maximum of 1.8m between beams so two beams were required thus doubling up the number of posts.

We cut the posts to length on the ground and then connected our beams using a joiner block to create one long beam. They were half checked and the balau beams of 30 x 220 were placed and secured on the half checks. Galvanised hex bolts were used to secure the beams to the posts.

The joists went on next and were left long so that the deckboards could start from the house side and the joists cut off once we reached our desired depth. If the joists are cut to length before the deckboards go on, then it will result in a half deckboards being used to finish it on the house side. What can also happen is that the last deckboard is not only a half deckboard but also a wedged shaped one. So deckboards are always started on the house side and run to the desired depth and the joists are then cut to fit.

Timber deck installers Durban

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On these types of decks I also like installing a fascia beam of the same size as the joists so as to provide support on the front of the deck as well as providing a beam that the balustrade can be attached to. Without this the balustrade would need to be attached to the main beam beneath which would mean the main beam would need to be set near the end of the deck and perfectly square to the deckboards or the balustrade will run out of parallel to the boards. With this method it is not important if the main beam is not perfectly square as it doesn’t have to line up with anything on the deck itself. It is merely there for support and the tolerance is therefore much greater.
The balustrade uprights of 60 x 60 were installed prior to the deckboards so that we could deck around them by notching the boards. Once the boards were down, the cross supports on the balustrade were installed 100mm off the deck surface for the bottom one and flush with the top of the posts for the top one. This top cross support can sometimes be set 100 down from the top of the uprights, but setting it directly underneath the capping provides greater support to the capping and will prevent it from bowing over time. Pickets of 25 x 30 were then set equidistant apart between balustrade uprights, cut to length and a capping of 30 x 102 placed on top and secured.

Screw holes were epoxied closed with a saw dust mixture to match the colour, sanded and sealed.

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Wooden Sundeck Built in Forest Hills Durban

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sundecks Durban

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This sundeck we built in Forest Hills Durban was an add-on to a deck we completed in 2012. The client initially built a 20 odd square metre deck off the front of his grant flat. It was then decided to extend the deck around the corner to tie up with the kitchen door.
We needed to decide which way the deck boards should run. Traditionally they should have run the length of the deck extension, but because of the way the existing deck had been built, it would have resulted in an odd line that would have been visually unappealing. Had the extension been built at the same time as the deck then the deckboards could have met at a 45° angle to turn the corner. Instead they would need to either meet at a 90° angle or they would need to run the same way (i.e. the width of the deck rather than the length). It was decided to run them the same way as the existing deck resulting in them running the width of the deck rather than the length.

With this in mind we set out to lay the substructure which consisted of long joists of about 9.2m. The width of the deck was 1.2m so we set 2 joists and a cleat along the wall. The challenge in setting such long joists of course is to ensure that they are set straight. Our joists were each 4.5m long so had to be joined in the middle without allowing them to bend or bow at the join. It was easier to join the joists beforehand, set a false deckboard of pine to hold them at their 1.2m width and then dig our holes for posts. We used H4 CCA gum poles as posts as they would not be visible from the outside and budget did not allow for balau posts. The poles were half checked to accept the joists, secured to the joists using kalgard 60mm screws and concreted in with 6 inch nails hammered into the base to prevent the post from sinking over time. A dry mix was used so as to be able to work with the post and joist immediately after setting them.

wooden decks Durban

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There was a concrete gas bottle plinth that was not decked and we had to deck around that and fill the vertical surfaces with balau cladding for aesthetics. Also the plinth that existed directly outside the kitchen door was slightly higher than we would have liked and as such we could not use our 30 x 102 joist and had to use a 30mm baton to arrive at the same height as the rest of our joists.
Once the substructure was down it was relatively plain sailing as our rough pre-cut balau deckboards were screwed down. We intentionally left them slightly long and after they were all down, snapped a chalk line along the edge and cut with a skill saw to get a straight line.

We cladd a few ends to close it all in, epoxied our screw holes to prevent water collecting in them and being soaked up by the end grain. Once dry we sanded flat and sealed using a top quality timber preservative with an oak tint.
A few pot plant stands were thrown in from the scrap off cuts which will now keep the pot plants off the deck and allow the water to drain away quickly and prevent accelerated degradation of the balau.

10m² took us 2 days to complete. The crew received a nice bonus based on square meterage and it was off to the next job.

For a free no obligation quote, or simply for an advice, please use the form below to contact me or you can call us on 082 496 5444.

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