The mason installs these, not the lighting crew. And the window closes when the cap goes down.

Ask the mason for a wire channel, weeks before you need it

Kichler’s guidance contains the instruction and it is easy to read past: you may need to ask the hardscape contractor to create a channel for your fixture wire run. That is a request to a different trade, during their work, ahead of a step they do not think of as a lighting deadline. The practical version is to raise lighting at the point the hardscape is being designed, not when it is being finished, and to be specific about what you need: a channel along the top course, sleeves through or behind the wall where cable has to cross, and the cap left off until the fixtures and wire are in and tested. None of that costs the mason meaningful time if it is known in advance, and all of it is expensive afterward.

Sleeve the wire, and know what the sleeve is for

Running cable loose through a wall is not the same as sleeving it, and the reasons are specific rather than general caution. Flexible PVC conduit sleeves protect the low voltage lines from moisture, from shifting masonry blocks, and from soil compression, and they are placed inside the hollow cores of retaining wall blocks or tucked behind stone veneer before the final mortar or adhesive sets. The payoff is stated as keeping the lines safe and easy to service in the future, which is the part that matters: a sleeved run can be pulled and replaced, and a cable mortared directly into a wall cannot be replaced at all without taking the wall apart.

Test the circuit before anything gets capped

The most obvious item on this page and the one skipped most often, because at the moment it applies everybody wants to finish the wall. The instruction is explicit: connect the fixtures and power the transformer before capping the wall or installing final treads, since confirming function before everything is sealed saves significant time if there is a wiring issue. The reason it gets skipped is scheduling pressure from a trade that is not yours, and the reason it matters is that a single bad splice inside a capped wall is indistinguishable from a dead fixture and is reached by chiseling. Power it up, look at every fixture, and only then let the caps go down.

Understand what the retrofit actually involves before you accept it

Retrofitting is entirely possible and it is a different job. On a segmental or dry-stacked wall you lift the capstones with a masonry chisel and hammer, working slowly to avoid damaging the stone, then cut channels roughly half an inch square along the top of the blocks with an angle grinder and diamond blade, wearing eye protection and a dust mask because it is genuinely dusty work. On a mortared stone or brick wall it escalates: each fixture needs a hole core drilled with a diamond bit two to three inches across, and on hard stone like granite you should expect the bit to wear quickly and budget for spares. Sleeves get set in masonry adhesive and cure for twenty-four hours before the light goes in. Then the caps are re-bedded and the wall has to look undisturbed.

A modular wall is the easy retrofit and a mortared one is not

This distinction decides the price of a retrofit and it is visible from across the yard. On a dry-stacked stone or segmental block wall, individual blocks can be removed to create cavities for the fixture sleeves, and that is described as the easiest retrofit precisely because the wall is modular: pull a block, set the sleeve, run the lead up the void behind, reinstall the surrounding blocks. A mortared wall has no such option and every fixture becomes a core drilling operation. So when somebody asks whether lighting can be added to an existing wall, the useful first question is what kind of wall it is, and the answer changes the estimate by an order of magnitude rather than a percentage.

The cleaner it looks, the harder it is to fix, and that is a real trade

The most useful sentence in this whole subject comes from somebody describing their own retrofits, and it generalizes well beyond hardscape: the cleaner the installation looks, the more painful it is to service. The concrete version is worth quoting too, because it makes the scale obvious. A path light you replace in thirty seconds. A recessed fixture embedded in mortar requires chiseling out grout, disconnecting the lead, and re-pointing the stone around the replacement. A manufacturer confirms it for hardwired fixtures when answering a question about their own product: the body and flange are one piece, so replacing the whole unit would mean grinding out fresh clearance under the capstone. The invisible integrated look is the entire appeal, and it is also a commitment. Customers should choose it knowingly rather than find out in year six.

Leave service loops, because you will not get another chance

A service loop is extra cable coiled at each fixture location, and it is described as all-important for future maintenance. In hardscape it is more than that, because it is the only slack that will ever exist. Once a run is sleeved through a wall and the caps are bedded, the length of cable at each fixture is fixed forever, and a splice made with no slack cannot be remade. Two things follow: leave generous loops at every fixture, and leave them somewhere reachable rather than inside a mortar joint. This is also the point where the connector guidance from elsewhere in this category matters most, since a splice inside a wall is the least serviceable splice on the property.

Match the fixture type to the surface, and check the beam on steps

The two common hardscape fixtures do different jobs and are not interchangeable. An under-cap light uses a flat flange sandwiched between courses so the source disappears beneath the cap lip, which suits a sitting wall, a retaining wall or a column. A louvered step light is a flush unit set into the vertical riser, with angled slats or a directional faceplate specifically to block outward glare and push light down onto the tread, which is the right answer for stairs and the wrong one for a wall face. On steps, check the beam spread as well: one that is wide enough lights the full tread from a single fixture per step, while a narrower one leaves the dark corners that make a stair look patchy. And for anchors into block, use a hammer drill with a concrete bit rather than a driver, which one installer reports learning the hard way.