Flat Roof Patios in Maddington

The structure coming down is part of the job. Old Maddington patios are often timber-framed with corrugated sheeting, and on anything of that vintage the sheet may be asbestos cement rather than steel or fibreglass.

Asbestos removal is licensed work with its own handling and disposal rules. It is not a weekend demolition, and it is not something to find out about after the crew has arrived.

So we establish what the existing roof is made of at the quote. That decides who takes it down, what it costs and how the install gets sequenced.

With a yard this size the roof does not have to be bolted to the back wall. A freestanding structure out in the yard is a real option, and on some blocks it is the better one.

It sidesteps the fixing question entirely. No cutting into an old tile roof, no flashing detail at the gutter, and the height is set by what suits the space rather than by where the existing fascia sits.

It also lets the patio face where you want it. Away from the western sun, toward the garden, or over the pool, rather than wherever the back door happens to be.

The Canning flats carry reactive clay. It swells with winter rain and shrinks back through summer, and the movement is worst in the top layer where a shallow footing sits.

That is a site classification question, and it feeds straight into the footing schedule the engineer produces. Deeper or wider than a sand site, and sized against the wind classification at the same time.

There is no way around it and no honest way to price it sight unseen. The ground under your block sets the number.

It also rules out reusing the old footings. Whatever the 1980s pergola stood on was sized for a lighter structure under a different code, and its survival is not evidence the ground is well behaved. Every post on the new patio gets its own hole.

Maddington is flat and the soil is slow. Those two together mean stormwater has to be designed rather than assumed, because there is no natural fall doing the work for you.

Soakwell capacity goes up against what the same roof would need in sand, and the array often spreads wider and shallower to use the upper soil that actually drains.

Overflow gets a route on the plan. Water leaving a full soakwell on flat ground ponds wherever the level is lowest, and on plenty of Maddington blocks that is beside the house.

Land around Maddington station and along the highway side has been coded for higher density, and the older lots in that radius have been steadily splitting.

What comes out is a long narrow rear lot with a driveway down one side. The old square of lawn becomes a strip of paving, often with a boundary wall on one side and a fence close on the other.

A flat roof handles that shape better than anything pitched. One plane, one consistent height, and no ridge to run out of headroom under at the low edge.

The Class 10a building permit is lodged with the City of Gosnells before work starts. Site plan, elevations, structural engineering for the assessed wind classification, and a stormwater design that reflects the clay.

It can go in uncertified for the council to assess, or certified with a certificate of design compliance from a registered building surveyor.

Development approval is a separate track under the R-Codes, and on the post-subdivision lots it is setbacks and open space that decide whether it is needed.

On a replacement patio the paperwork still applies. A new structure on the footprint of an old one is new work, and the fact that something stood there for thirty years does not carry across.

Big Maddington blocks usually have something parked down the side. A caravan, a boat, a trailer, or a shed at the back that still needs a vehicle to reach it.

A patio can close that off without anyone noticing until it is built. One post in the wrong place and the gate that used to swing open now leads to a gap nothing will fit through.

So the access route gets measured before post positions are set. Widening a span to keep a driveway clear is a beam decision, and it is far cheaper to make on paper than on site.