Flagstone is not interlock with a different face. Every piece is a slightly different thickness, the joints are wide and irregular, and the whole surface has to be bedded piece by piece rather than screeded to one level. That makes it slower work and it is why a flagstone repair prices differently.
A manufactured paver is a known thickness, so the bedding under a whole area can be screeded to one depth and every unit lands level.
Natural flagstone varies piece to piece, sometimes by twenty millimetres across a single slab, which means the bedding has to be built up or taken down under each one individually to get a level walking surface.
Skipping that is why so many flagstone patios rock: the pieces were laid on a flat bed and only the thickest ones are really bearing. The joints are the second difference. Wide irregular gaps need a product rated for the width, and ordinary narrow-joint polymeric sand simply slumps and cracks out of them.
Where the joints are very wide, a stabilised aggregate or a mortar joint is the right answer instead. See how polymeric sand is chosen by joint width, what uneven pavers need by comparison, and how moss and algae behave on natural stone.
Flagstone Repair
How It Runs
Four steps to flagstone that sits still
Map before lifting
Pieces are photographed and marked before they come up, because a flagstone pattern is unique and does not go back by guesswork.
Bed each piece to itself
The setting layer is built up or taken down under every individual stone, since they are all a slightly different thickness.
Check every piece for rock
Each one gets walked and pressed before the joints go in, because a rocking slab is far harder to fix once the joint has set.
Joint to the width
The product is chosen for the gap: polymeric for narrow, stabilised aggregate or mortar where the joints are wide and irregular.
Cracked Slabs
A split flagstone is rarely replaceable
Natural stone comes from a specific quarry run and even the same quarry will not repeat a colour and grain exactly years later. So a cracked slab usually means either relocating a piece from a hidden part of the surface or accepting a visible difference.
We check the property for spare stock before ordering anything. See how discontinued pavers are handled on the manufactured side, what polymeric sand can and cannot do in a wide joint, and how uneven pavers are re-bedded.
Rarely replaceableA split slab
Spare stock on siteChecked first
Never repeatedQuarry run
Related Work
Other replacement work in Toronto
What a flagstone surface usually needs at the same time.
Because it was bedded on a flat screed. Natural stone varies in thickness, so only the thickest pieces are really bearing and the rest sit over voids.
Only where the joints are narrow and you use a product rated for that width. In wide irregular gaps it slumps and cracks out within a season or two.
Yes, generally $12 to $22 a square foot, because every piece is bedded individually rather than a whole area being screeded and laid to one level.
Sometimes, from spare stock on your own property. Buying new natural stone years later rarely matches, because colour and grain vary by quarry run.
It can be, and it deepens the colour, but it also makes the surface slower to dry. On a shaded patio that can mean more moss rather than less.
Almost always. Natural stone does not fail the way a thin manufactured unit can, so what comes up generally goes back. The exception is a slab split across its narrow dimension, and we show you that one rather than describe it.
