How to build a free-standing deck?

Turts

I live in a high white ant area in Perth and currently removing the old deck so as to install new with H4 pine frame.

I dont want to build directly of the house ie anchor to a ledger brd instead I want to leave a gap so as to spray with white and treatment.

Any suggestions .Its low 100mm of ground and about 3.5m x 6m.

Steve

MitchellMc

Welcome to the Bunnings Workshop community @Turts. It's marvellous to have you join us, and many thanks for your question about building a deck.
 

It's definitely a common and sensible approach—especially in termite-prone areas like yours—to keep the deck free-standing and avoid fixing it directly to the house. Installing a row of posts along the house-side edge instead of using a ledger board works well and gives you that important gap for ongoing inspections and treatments.

Since you're in a high white ant area, have you considered using a steel subframe instead of H4 pine? Pairing a steel frame with composite decking can be a great long-term option. It significantly reduces the amount of timber in the structure, making it far less attractive to termites, and composite boards also hold up well in Perth’s climate.

That 100mm clearance is quite tight, so also keep in mind things like ventilation and drainage under the deck—those will be really important to avoid moisture buildup, which can attract pests and degrade materials over time.

Please let me know if you have any questions.

Mitchell