Porcelain patio in progress, Gloucester

How should porcelain be bedded?

On a full wet mortar bed, with a slurry primer brushed onto the back of every slab. Porcelain is effectively non-porous, so it cannot bond to a semi-dry mix — five spots of mortar under each corner is why so many porcelain patios sound hollow and crack.

• Slurry primer on the back of every slab
• Full bed, no voids under the slab
• Slab tapped down and levelled before the mortar goes off

Why photograph the work half finished?

Because the build-up is the part you cannot inspect once the job is done. Anyone can produce a tidy final photograph; the bedding, the falls and how covers were handled are what you are actually paying for.

How is a cover cut into a slab pattern?

The tray is set level first, then slabs are cut on a wet saw to fill it with the same joint widths as the surrounding field. Aligning the tray to the pattern before bedding is what makes the cover disappear rather than look inserted.