Recessed Lighting Install Guide 2025

Why This Guide Exists

Callbacks kill profit. Job-site audit found that crews using a pre-install checklist reduced change orders by 25 percent. That checklist is in this guide—tight, code-backed, and tested in crawlspaces, sloped lids, and every half-finished ceiling you'll come across.

Recessed Lighting 101 (Quick Reference)

Why Layout and Specs Matter

Choosing the Right Housing

1. Ceiling Access

   • Open joists? Use new-construction cans

   • Finished lid? Use remodel cans

2. IC or Non-IC

   • IC-rated cans are required where insulation touches the housing (NEC 410.116, [WAC Lighting][2])

   • Non-IC cans need 3 inches of clearance—usually not practical in attics

3. Airtight (AT)

   • IECC requires ≤ 2 cfm at 75 Pa for conditioned spaces ([ICC Digital Codes][1])

   • Look for the UL 1598 “AT” marking ([UL Solutions][3])

4. LED Engine

   • Retrofit kits drop into old cans and cut wattage by up to 80 percent

   • Integrated housings are ready for Title 24 and DLC specs

 Shop Revco’s IC/AT Housings

Layout in Three Numbers

1. Spacing Rule – Keep cans half the ceiling height apart (8 ft lid → 4 ft spacing)

2. Perimeter Rule – First row should land 3 ft from walls for even coverage

3. Task Zones – Add direct overhead light above sinks, cooktops, and workbenches

Selection Workflow

Install Process: Start to Finish

Tools You’ll Need
Hole saw (4, 5, or 6 inch), non-contact tester, 14 or 12 AWG NM-B cable, PPE, fire-rated sealant, LED-compatible dimmer.

Steps

1. Shut off breaker and verify power is off

2. Mark and cut openings using the template

3. Run NM-B cable—secure within 12 inches of each box and every 4.5 ft (NEC 334.30, [Electrical License Renewal][5])

4. Make connections: hot-to-hot, neutral-to-neutral, and ground

5. Install housing, making sure it's flush and clips are engaged

6. Seal air gaps with fire-rated caulk

7. Label circuit and date

8. Turn power on, then test for flicker and hot spots

Need a second opinion? Revco counter pros average 12+ years in the field. Give us a call before you cut.

Troubleshooting Reference

Crew Q&A

Can I install on a vaulted ceiling?
Yes, with slope-rated housings.

What size hole saw do I need?
Check the spec sheet. Common sizes: 4-7/8 in for 4 in trims, 6-1/4 in for 6 in trims.

Can one switch handle eight cans?
Yes, as long as the total VA stays below the breaker rating (e.g., 15 A = 1,440 W at 120 V).

Why is it buzzing at low dim?
You’re mixing a triac dimmer with a 0–10 V driver. Swap the dimmer.

Code References

Material Checklist

• Remodel or new-construction IC/AT cans

• UL-listed LED modules (DLC preferred)

• 90+ CRI baffle trims

• LED-rated dimmers

• 14/2 or 12/2 NM-B cable

• Hole saws: 4, 5, 6 inch

• Fire-rated caulk and job labels

• PPE and voltage tester

Get Everything in One Cart

Recap

• Start with layout: half-height spacing, 3 ft from walls

• Only use IC/AT when insulation is present

• Match dimmers and drivers to avoid flicker

• Air-seal every fixture to pass blower door tests

• Include code references in your bids—end the debates before they start

Need Help with Specs or Materials?

Revco Lighting & Electrical Parts Supply
Serving Long Island since 1978. Six locations. Real people still answer the phone.

 Call your local branch or explore the Recessed Lighting section online.
Revco—built for pros