Recessed Downlight Retrofit: IC Rating and Cutout
NEC 410.116 requires a Type IC (UL 1598) listing wherever ceiling insulation will touch a recessed downlight housing; cutouts run 4-3/8 in to 6-5/8 in for Juno and Lithonia remodel housings, and NEC 410.118 bars using the fixture opening to reach a separate junction box.
Applies to Remodel (old-work) recessed downlight housings, 4 in to 6 in diameter, installed through existing US gypsum-board or plaster ceilings between joists; governed by NEC (NFPA 70) Article 410 and UL 1598 luminaire listings.
When retrofitting a recessed downlight into an existing ceiling, what do the NEC and manufacturer manuals require for IC rating, cutout size, and junction-box access, and can it be done through a single cutout instead of removing the whole ceiling?
| Item | Requirement | Code or manual section | Source |
|---|---|---|---|
| IC rating for insulation contact | A recessed luminaire must be listed Type IC if thermal insulation will touch the housing, wiring compartment, or driver | NEC 410.116(A)(1)-(2) | up.codes |
| Non-IC clearance from insulation and combustibles | A non-Type-IC housing must keep insulation at least 3 in away and recessed parts at least 1/2 in from combustible material | NEC 410.116(A)(2), 410.116(B) | up.codes |
| IC listing test basis | Type IC classification for direct contact with building insulation is tested and listed under the UL luminaire safety standard | UL 1598 Standard for Safety Luminaires | elecenghub.com |
| Cutout diameter, 4 in IC remodel housing | Cut a 4-3/8 in diameter ceiling opening for a 4 in Type IC remodel housing | Juno Type IC & TC Recessed Housing installation instructions | usesi.com |
| Cutout diameter, 5 in IC remodel housing | Cut a 5-1/2 in diameter ceiling opening for the Juno IC20R 5 in Type IC remodel housing | Juno IC20R installation instructions | electricbargainstores.com |
| Cutout diameter, 6 in IC remodel housing | Cut a 6-5/8 in diameter ceiling opening for a 6 in Type IC remodel housing | Juno Type IC & TC Recessed Housing installation instructions | usesi.com |
| Remodel clip ceiling-thickness range | Four perimeter remodel clips on the Halo H7RICT 6 in housing secure to ceiling material from 1/2 in to 5/8 in thick without screws into joists | Halo H7RICT product listing | homedepot.com |
| Joist-bay dimension and direct-burial rating | The Lithonia L3R 4 in IC/non-IC remodel housing: direct-burial-in-insulation rating, 2 in x 6 in or 2 in x 8 in joist bay dimension, clips adjustable up to 1-1/4 in | Lithonia Lighting L3R product page | acuitybrands.com |
| No sole access to other junction boxes | A recessed luminaire opening cannot be the only means of reaching a separate outlet, pull, or junction box unless that box is an integral part of the listed luminaire | NEC 410.118 | up.codes |
| NM cable entry into the housing's integral box | Nonmetallic-sheathed cable entering the housing's wiring compartment must extend at least 1/4 in past any cable clamp and be secured to the box, except where the box is not larger than 2-1/4 in by 4 in and the cable is stapled within 8 in of the box | NEC 314.17(B)-(C) | up.codes |
Installation
- Locate ceiling joists with a stud finder and confirm the fixture location falls between two joists, not under one.
- Drill a small pilot hole at the marked center and check above with a flashlight or bent wire for obstructions before enlarging the opening.
- Cut the ceiling opening to the housing's specified cutout diameter (4-3/8 in, 5-1/2 in, or 6-5/8 in) with a jab saw or hole saw.
- Fish the supply cable to the opening from an existing switch, outlet, or fixture box, or from above if attic access exists.
- Feed the cable into the housing's integral junction box through a knockout, leaving at least 1/4 in of sheath past the clamp, and make the wire connections.
- Push the remodel housing up through the ceiling opening and engage the perimeter mounting clips against the back of the drywall or plaster.
- Match the housing's IC or non-IC rating to the ceiling's insulation condition before closing in or restoring insulation around it.
- Install the trim or light module and restore insulation only to the clearance the housing's listing allows.
FAQs
Do you have to remove the whole ceiling to install a recessed downlight in an existing ceiling?
No. Remodel (old-work) recessed housings mount through a single round cutout (4-3/8 in, 5-1/2 in, or 6-5/8 in depending on housing size) and are held to the drywall by perimeter clips, per the Juno and Lithonia remodel-housing installation instructions; no joist attachment or full drywall removal is specified.
What is an IC rating and when is it required?
Type IC (insulation contact) is a UL 1598 listing that lets a housing touch thermal insulation directly; NEC 410.116(A) requires a Type IC listing wherever insulation will contact the housing and keeps insulation at least 3 in away from a non-IC housing.
What size hole do you cut for a recessed downlight retrofit?
Cutout diameter follows housing size: 4-3/8 in for 4 in housings, 5-1/2 in for 5 in housings (Juno IC20R), and 6-5/8 in for 6 in housings, per Juno's Type IC & TC remodel housing installation instructions.
Can the recessed light opening be used to reach another junction box in the ceiling cavity?
No, unless that box is an integral part of the listed luminaire; NEC 410.118 bars using a recessed luminaire opening as the sole access to a separate outlet, pull, or junction box.
How is the supply wire secured inside the fixture's integral box?
NEC 314.17(B)-(C) requires the nonmetallic-sheathed cable to extend at least 1/4 in past any cable clamp and be secured to the box, with an exception for boxes up to 2-1/4 in by 4 in when the cable is stapled within 8 in of the box.
Resources
- up.codes - NEC 410.116 Clearance and Installation
- up.codes - NEC 410.116 Non-Type IC
- up.codes - NEC 410.118 Access to Other Boxes
- up.codes - NEC 314.17 Nonmetallic-Sheathed Cable Entering Boxes
- UL 1598 Standard for Safety - Luminaires (2021)
- Juno Type IC & TC Recessed Housing Installation Instructions
- Juno IC20R 5 in Remodel Housing Installation Instructions
- Lithonia Lighting L3R 4 in Incandescent Remodel Housing
- Halo H7RICT 6 in Remodel Housing, Insulation Contact - The Home Depot