How do I extend the existing footprint of my deck by integrating into the existing deck?

[jfabre]

Hi there, i want to extend my existing deck to the end of my house.  The new area would be approx, 1700x1600.

My existing deck is constructed of 90X90 F5 TPine Bearers and 90x45 TPine joists, with merbau on top (90x19).

The proposed area would not have a roof on it just flooring and the height of flooring would integrate with the existing flooring.

My proposed plan is to:

1) Fix a ledger securely against the wall of the house.  I am proposing 90x45 F5 TPine. The purpose would be to act as the support for the bearers, joists and decking instead of stumps.  I do not want to dig actual footings as that requires a permit.

2) Securely fix metal stirrups into existing concrete for the bearers, being 3 (bearers) of  H5 90X90 Bearers, to achieve a 1600 mm span.  I could reduce this to 1200 if required, but am keen to keep it at 1600mm span if possible for this size.

Bolt the bearers into the stirrups and run them to the house, seating them into metal hanging brackets, that are securely bolted into the house wall. These bearers would be on top of the ledger but seated on hangers.

3) Run the joists on top of the bearers, nailing the side under the deck into existing joists, running the other side of the joists onto the last bearer, using metal clamps nailed from the joists to the bearer.

4) Run the merbau decking on top and on the side to "cap" of the edges, ie neaten it up.

Does that make sense? I dont want to dig in any concrete stumps for this area as then I need a permit and want to avoid that cost for this area, so I am using the ledger under the bearers to perform that function.

I have attached photos of the area, let me know if you need anything else. 

[StevieB]

Welcome to the Bunnings Workshop community @jfabre and thanks for sharing about your project with us.

Let me tag @Adam_W, @tom_builds and @MitchellMc to help kick off this discussion.

Look forward to following along with your project.

Stevie

[EricL]

Hello @jfabre

Thank you for joining us and sharing your deck extension project.

Maximizing your deck space is a great way to add an extra feature to your house. Have you thought about using Builders Edge Pedestal Foot Bigfoot Xl 70 - 170mm as an alternative to buried stumps? I also recommend looking at the TuffBlock 300 x 300 x 90mm Instant Foundation System Deck Support. Your proposed plan will transfer all the load to the bolts and bricks that are holding the extended deck structure. I propose using the pedestal systems I've listed to hold the load of the bearer. 

Here is a link to a handy guide: How to build a low-level deck by @Adam_W

Here is a link to one of our featured projects: Low-profile deck with screening and steps by @MGusto

Let me tag our experienced members @LePallet, @Brad, and @woodenwookie for their recommendations.

If you need more advice or information, please let us know.

Eric