Mike Deblis wrote:
Hi,

I'm looking for suitable LED lighting to put in the stringer to light every
2 or 3 treads on the stairs in our rebuild - about 6 lights in total. The
staircase is not in yet, so I can pretty much do what I want.

Ideally, we are looking for very low level lighting that is robust
(kick/bash-with-vacuum-cleaner-proof) and which has a shallow fitting.
because there is a cupboard under the stairs, we can hide the transformer in
there. We are intending to use ZUL202 series lights elsewhere as night-time
lighting for the hall & passageways. I have thought about decking lights,
but they tend to be quite chunky and the choice is huge. The lights would
have to have round fittings probably as square ones would look odd stuck in
a stringer. They also have to be fairly small diameter so as not to weaken
the stringer (my builder says), so the ZUL series stuff is too big anyway...

Be aware that some of the cheaper end of the market LEDs will have
significant dimming over time issues.
As well as a percentage of failure.
White and blue are probably especially bad for this, red, green are
essentially a mature technology that doesn't fail.
White is worst, as the phosphor can be screwed up, but blue LEDs are not
as reliable at the cheap end of the LED market.
And replacing the lights later, or trying to find a match would be fun.

If it was me, I'd strongly consider DIY.
Drill a 6mm hole into the stringer, just above the tread, and pointing
downwards at an appropriate angle for the LED you choose.
Paint the inside of this hole black, as matt black as you can find.
Put the LED inside the hole, some 5-10mm back from the edge, and
you'll get light, with no glare, the only thing you'll see will be the
side-scatter from the matt black paint.

A 6mm routed groove all the way up the side of the stringer, some 10mm deep,
with a 6mm*6mm square section on top of it to hide the wires, is quite
adequate.
(if needed).
Having said that, I'm paranoid, and if I was doing this, I'd probably go
for the option of using 10mm holes, and connecting the LEDs in each
hole using 3.5mm mono headphone plugs.
This way you can easily change it if an LED fails, or even change colurs.