How much weight does a solar array add to my NM roof?

Typical 20-panel residential array adds 3–4 psf including racking. Most NM homes framed for 20 psf live load handle it, but 1980s trusses with 2x4 top chords should be evaluated before install.

What wind uplift do I design for in Albuquerque?

ASCE 7-22 gives Albuquerque a 115 mph ultimate design wind speed. Exposure C (open terrain) is typical for the West Mesa and Rio Rancho — plan for ~29 psf uplift on roof-edge zones.

How many lag bolts per panel?

Rule of thumb is 4 attachments per panel on 24 in rafters, 3 per panel on 16 in rafters — but always verify against the racking manufacturer's span table and local wind zone.

Free tool · Pre-install checklist

Solar panel weight & attachment planner

Name: Roof Doctor NM
Address: Albuquerque, NM, US
Telephone: (505) 595-7203
Price range: $$

Before you sign a solar contract, know what the array actually weighs, how much wind uplift the roof will see, and how many lag bolts your rafters need. If your installer can't answer these three questions, get a second bid.

Your array

Panel model

Panel count

System size: 8.8 kW DC

Roof pitch (rise / 12)

5/12 pitch ≈ 23°

Rafter spacing

Wind exposure

Most ABQ homes are Exposure C. Sandia foothills and West Mesa ridges are D.

Load report

Total dead load

1,590 lb

3.79 psf over 420 sqft

IRC live-load check

PASS

Under 5 psf rule of thumb

Uplift · corner

40.3 psf

Zone 3 ASCE 7-22

Uplift · field

25.9 psf

Zone 1 mid-roof

Attachments (lag bolts into rafters)

121

Minimum count with 15% safety factor. Spec: 5/16" × 4" stainless lag through flashed L-foot into rafter, EPDM-gasket washer. Rail length ordered: ~130 ft.

Numbers are pre-design estimates for NM (Vult = 115 mph, Risk Cat II). A stamped structural report is still required for permit — this tool tells you if your installer's numbers pass the sniff test.

Is my roof solar-ready?Call (505) 595-7203

What installers gloss over

Three questions to ask before you sign.

"Will my rafters take the load?"

A 20-panel array is ~1,300 lb spread over 420 sqft — usually fine on 2x6 @ 24" o.c. But 30+ panels on undersized 2x4 rafters needs sistering.

"How is the array flashed?"

Every lag penetration is a leak risk. Insist on QuickMount PV or IronRidge FlashFoot 2 — not just butyl tape.

"Are you re-roofing under the array?"

If your shingles have <10 yrs left, re-roof BEFORE solar. Removing/reinstalling an array to re-roof later costs $2,000–$4,000.

Next step

Roof + solar package? We coordinate with 6 NM installers and warranty every penetration for life.

Book the free on-site inspection, or send a photo and we'll tell you what to do next. No sales pitch — we don't install roofs.

Book Free Inspection See a sample report

Want a real set of eyes on it?

The tool is a starting point — a written scope from a 20-year NM roofing veteran is what wins bids and insurance claims.

Book $0 walk-around Call (505) 595-7203 Text a photo