Question regarding a low-level deck frame

[DJ11]

Hi All,

I am building a low level deck to be in flush with my current alfresco. It's a 5.5x4 deck, and I am using composite deck.  The write-ups from this community has been very helpful for me in designing my deck so far. However, I need some help from experts in this group in regard to the underlying timber frame design. I am not going with a bearer/joist setup otherwise i will have to excavate a lot, Its already a low ground so digging further will cause drainage issues. Hence, i will be just using tuffblock to support the joists. On the sides, i will have 90x90 footings concreted to the ground to provide extra support. For the joists I was thinking to use 140x45 H3 timber throughout initially, but budget is a major constraint and wanted to check if i can use 90x45 H3 instead and if it will be structurally very sound. That itself will save me at least $500 straight away. However, i don't want to go that way if it is structurally not strong. I will attach the design i have come up with for the frame.

Secondly, I am building an L-shaped in-built seating area on the deck, and i wanted to check what size wood you recommend that I should use to build the frame for the sitting area (70x35 or 70x45 or 90x35 or 90x45). I will be covering the frame with composite decks to match the deck so that it looks like one piece.

Any help on these queries will be greatly appreciated.

Please feel free to ask more questions, as i don't know if i have given all that you need to easily answer my queries.

Thanks in advance.

[EricL]

Hello @Duck

Just to be clear on the sequence the ground has to be compacted and then covered with weedmat then the pavers are placed into position. I then recommend putting drainage gravel on top of the weedmat then you can position the pedestals in place over the pavers.

Here is an amazing low-level deck project our Workshop member has shared: 

• Low-level composite deck over concrete and soil by @oninpena

This is a very good example of how the pedestal/paver combo is installed before installing your decking frame over it.

If you need further assistance, please let us know.

Eric