Flat Patios Canning Vale

The standard Canning Vale house presents a straight structural fascia across the back, an alfresco about three metres deep under the main roof, and a paved area that runs out from it.

Everything about that is helpful. The fixing line is predictable, the fall of the existing roof is known, and there is no odd step in the slab to design around.

The alfresco itself is the problem people call about. It is shaded and it is dry, and it has never once been big enough for the table the family actually owns.

The Fremantle Doctor reaches here, but it arrives late and it arrives tired. By the time it does, the brick walls, the driveway and the paving have absorbed a full day of sun and are giving it back.

That is a radiant heat problem more than an air temperature one. Single-skin Colorbond over paving re-radiates downward all evening, which is why the space is still unpleasant at nine when the forecast said it had cooled off.

An insulated panel roof is the honest answer here. The foam core slows the heat coming through, the underside stays cooler to sit beneath, and it gives you a finished ceiling to mount a fan into.

Running a new flat roof out from an existing alfresco is the most common job in this suburb, and it is the detailing that separates a good one from an obvious one.

The junction is where it happens. The new roof picks up on the existing beam or wall, keeps its own fall moving away from the house, and avoids creating a dead spot where two falls meet and water sits.

The ceiling line matters just as much visually. A step or a change of material at the junction is the thing everyone notices from the kitchen window, so the two ceilings either line up or they are deliberately separated by a shadow gap.

People ask us to match the new patio to the existing roof, and it is worth being straight about what matching means. A Colorbond roof installed in 1998 has faded, and new sheet in the same named colour will not look identical to it.

There are two ways through that. Accept a close match and let the slight difference sit at a clean junction, or pick a deliberately different tone so it reads as an addition rather than a failed match.

Our usual recommendation is the second. Taking the patio colour from the gutters, the window frames or the fencing gives a result that looks chosen, which the eye forgives far more readily than a near miss.

Much of Canning Vale drains well. There is sand over the top of a good part of the suburb and soakwells in it recover between storms the way you would want them to.

It is not uniform. Heavier material shows up in patches, more often toward the Southern River and Ranford Road side, and where it does the soakwell array has to be sized against soil that accepts water grudgingly.

The first footing hole settles the argument. That is why we would rather auger a test hole at the site measure than quote a stormwater design off an aerial photograph.

A patio is a Class 10a structure, so a building permit is needed before work starts. The only question is which counter it goes across, because the City of Canning and the City of Gosnells both cover parts of Canning Vale.

Either way the pack is the same. A site plan, elevations, structural engineering for the assessed wind classification and a stormwater design suited to the soil, lodged uncertified for assessment or certified with a certificate of design compliance attached.

Check the address rather than assume the suburb. Both councils publish property lookups, and confirming it early avoids the wasted fortnight that comes from lodging in the wrong place.

Canning Vale carries a substantial light industrial area along Bannister Road and the streets around it, and some residential blocks sit close to that edge.

For most jobs it is a positive. Steel suppliers, fabricators and roll-formers are minutes away rather than across town, which keeps deliveries short and makes a mid-build adjustment easy.

Where a block actually adjoins the industrial land, a solid roof edge or a screen on that side is worth considering. It is a sightline and dust question rather than a structural one, and it is cheaper to design in than to add later.