Free-standing or fixed to the house
A true floating deck is free-standing: it sits on its own piles and is not fixed to the house. That keeps water away from the house wall and avoids fixing into the cladding. A ground-level deck can also be fixed to the house where that suits the layout better.
Ventilation and drainage
The biggest risk with a low deck is moisture. A deck boxed in tight against damp ground with no airflow underneath is hard on the framing. We leave ventilation gaps, use H4 piles in the ground and H3.2 framing, and set the levels so water drains away from the house.
Clearance from the house
The deck surface has to sit below the floor level and keep the right clearance from cladding so water does not splash or wick into the wall. On some houses that limits how close to the door threshold the deck can be. We set this out before we start.
Decking over concrete
Building a deck over concrete in NZ, usually an old patio, is a common way to refresh a tired patio. It can work well with a low-profile frame on packers or pads, as long as the concrete drains, the frame stays ventilated and the finished height is right against the house. Where the slab is cracked or holds water, it is sometimes better to remove it first. We will look at it with you.
