IP Ratings for LED Strip: IP65 to IP68 Explained
IP20 to IP68 explained for LED strip: what each rating tests, which sealing method delivers it, and the three installation conditions that void the warranty.
HFY Applications Engineering · Published October 6, 2026 · 3 min read
An IP rating states resistance to solids and water: IP20 is bare strip, IP65 resists water jets, IP67 allows temporary immersion to 1 m, and IP68 is continuous immersion by agreement between buyer and supplier. None of them cover chemical attack, condensation inside a sealed cabinet, or a driver installed in the wet zone.
Key points
- The second digit covers water only — not salt, chlorine, cleaning chemicals or vapour.
- IP65 is a coating or sleeve; IP67 is a tube with potted ends; IP68 is full extrusion.
- Sealing costs 3–12% of light output depending on the method.
- Almost every outdoor strip failure is water pooling or driver heat, not the strip's rating.
What each digit tests
The first digit covers solids (0–6), the second covers water (0–8). For strip, only four water levels matter in practice:
| Rating | Test condition | Typical construction | Cost vs IP20 |
|---|---|---|---|
| IP20 | No protection | Bare FPC, adhesive backing | Baseline |
| IP54 | Splashing water | Conformal silicone coating 30–60 µm | +8% |
| IP65 | Water jets, 6.3 mm nozzle | Thicker coating or heat-shrink sleeve | +15% |
| IP67 | Temporary immersion, 1 m, 30 min | Silicone tube, glued caps, potted glands | +35% |
| IP68 | Continuous immersion, by agreement | Full silicone extrusion, potted entry | +60% |
The cost column is not decoration: it explains why a specification that says “IP68 everywhere” is usually written by someone who has not priced it.
The light cost of sealing
Sealing absorbs light, and the amount differs by method:
- Conformal coating: 1–3% loss.
- Silicone tube: 3–6% loss, because light crosses four surfaces.
- Full extrusion (neon flex): 8–12% loss, because the wall is 2–3 mm thick.
If the design needs 700 lm/m at the face, the strip must be specified to deliver 780 lm/m behind an extrusion. Quoting bare-strip flux for a sealed product overstates delivered light by up to 12%, and that shortfall appears as a dim installation, not as a warranty claim.
The three conditions that void a rating
Standing water. IP67 is a 30-minute immersion test on a new sample. A sign cabinet that collects 10 mm of water at the bottom keeps the lowest module submerged permanently. The strip’s rating is not wrong; the installation is. Mount strip 20 mm above the cabinet floor and drill a 3 mm drain.
Heat. A sealed strip in a closed profile or cabinet runs 15–20 °C hotter than the same strip in free air. That does not void the IP rating but it halves the life, which is covered in heat management.
Chemistry. Silicone resists water and UV well and chlorine badly. A spa surround cleaned weekly with a chlorine-based product hazes the profile within a year, and no IP rating addresses it. Specify pH-neutral cleaning in the handover document.
Where the driver goes
The most common outdoor failure is not the strip. It is the driver mounted inside the same sealed cabinet, where summer internal temperature reaches 60 °C and the electrolytic capacitors age at roughly double their rated rate.
The correct arrangement is: strip inside the wet zone with IP67 sealing, driver outside in a ventilated IP65 enclosure, and a cable gland between them. If the driver must be inside, derate it to 70% of rated load and specify a 105 °C capacitor grade.
For neon flex the sealing is inherent in the extrusion, which is why it is the default for facade work; for coated strip the sealing is a process step that has to be verified, and the IP sealing capability page describes the pressure test applied to every outdoor assembly.
This article describes general manufacturing practice for machined and fabricated components. It is not a substitute for a drawing-specific engineering review — tolerances, material selection and process capability depend on the individual part.