What joist support for low level deck?

[Bolton]

Hi, I’m about to start a low level deck with posts and bearers. I have a few questions. 

1. How far apart should the posts be on the external bearers and is it ok to fix with bolts and not notched. 

2. For the joists, do I have an internal bearer of simply support the direct joist with posts ?

Thanks in advance. Im hoping to use 120mm bearers. 

[Bolton]

Sorry just a few more questions as I’m starting the deck today. What should the clearance be on a low level deck ? Is 60mm at the bearers and 90mm at the joists ok and secondly I’m using 90x45 on the concrete patio with adjustable pedestals. No bearers is that ok ?

Again thanks in advance. 

[MitchellMc]

It's best to check with your local council regarding the height requirements for low-level decks @Bolton. They might have a minimum height. However, 60mm clearance to soil is fairly minimal. I'd recommend you prepare the area as best as possible and ensure water can drain away. I recommend you paint the underside of your bearers and possible joists with Gripset Betta 1L Waterproofing Membrane Bitumen Rubber. This will waterproof the bottom of them and assist with preventing the early onset of decay.

The pedestals effectively become the supporting bearer, so they are fine to use without one. Just ensure that you follow the span requirements for the 90 x 45mm. I generally recommend spacing the feet at 1000mm increments.

Please let me know if you have further questions.

Mitchell