Limbach Holdings, Inc. (LMB) | The Buildout — AI Infrastructure
The Verdict
Limbach is a mechanical, electrical, plumbing, and controls contractor for mission-critical buildings. It designs, installs, and maintains the systems that keep hospitals, industrial plants, and data centers running. Its role in the AI buildout is second-derivative: it does not make chips, servers, or software. It fabricates steel and piping packages and installs the mechanical and electrical plant in data-center shells. Management describes the demand as "data center" and never uses the word AI on its calls; the link to AI is the analyst's read-through from data-center capex, not the company's own framing.
| Market Cap | — |
| Revenue (TTM) | $684M |
| Revenue Growth | +23.7% |
| EBITDA Margin (TTM) | 8.5% |
| Net Debt | $42M |
| Earnings Beats | 6 of 7 |
| P/E (TTM) | — |
| EV/EBITDA (TTM) | — |
What We Like
- Bookings have run above revenue for three consecutive quarters — $225M, $209M, $182M — totaling $616M through Q2 2026, with Q1 book-to-bill of 1.5x.
- GCR backlog roughly doubled from $99M at the end of Q3 2025 to about $200M by mid-2026, per the CEO's answer to a margin question.
- For a $30M purchase price, the Simpcore/CYMCOR acquisition brings oversight of customer project budgets exceeding $8B; the healthcare analog is $3M of advisory revenue pulling through $60M of bookings, a 20x multiple.
- Q2 2026 operating cash inflow was $18.7M with free-cash-flow conversion of 98.2% of adjusted EBITDA, and the revolver was upsized to $125M on 2026-07-24.
- Data centers took about 27% of Q1 2026 bookings, and the company won a hyperscaler fabricated package expected to exceed $30M — roughly 3x its prior ~$10M project.
What We’re Watching
- Q3 2026 GCR gross margin is the first test of management's claim that the 14.5% Q2 figure was project timing, not execution.
- Healthcare demand: the second-half pickup promised in May 2026 had not arrived by August, and no 2027 timeline was given.
- Simpcore pull-through into bookings — management said it will look immediately but gave no timing, and growth is gated by recruiting staff.
- The securities-investigation solicitations that opened after the Q2 print (Levi & Korsinsky, SBS Law, Pomerantz); all are pre-suit, with no findings or exposure disclosed.
On the evidence, the thesis is mixed rather than intact. Demand signals are strengthening — $616M of bookings over three quarters, a roughly doubled GCR backlog, and near-100% cash conversion — but the profit engine is weakening, with gross margin down to 21.5%, a guided cut to 23–24%, and two quarters of negative organic revenue. The open question is whether the 23–24% gross-margin guide is a project-timing trough or the new base.
Earnings Beat
Q2 2026 revenue rose 21.9% to $173.5M from $142.2M, with $30.9M of the increase from the Pioneer Power acquisition. Total gross margin fell to 21.5% from 28.0%, and organic ODR revenue declined 3.4%. Net income was $4.7M, down from $7.8M a year earlier. Operating cash inflow was $18.7M — which management called its second-highest second-quarter operating cash flow since becoming a public company — and free cash flow was $13.7M, or 98.2% of adjusted EBITDA.
| Metric | Q2 FY2026 | Q1 FY2026 | Q2 FY2025 | YoY |
|---|---|---|---|---|
| Revenue | $174M | $139M | $142M | +22.0% |
| Gross margin | 21.5% | 22.4% | 28.0% | -650bps |
| EBITDA | $12M | $5M | $15M | −20.5% |
| EPS | $0.39 | $0.36 | $0.64 | −39.2% |
| Bookings | $182M | $209M | n/a | — |
Our results fell short of expectations driven by project timing and ongoing softness in health and institutional markets from elevated price sensitivity and market conditions pressuring gross margins.— Michael McCann, President and CEO, 2026-08-05
Management tone: Tone shifted from reaffirmation to reset between the two calls. On the Q1 2026 call management reaffirmed full-year guidance and said it was comfortable with consensus; on the Q2 2026 call the CEO opened by saying results fell short of expectations and answered the reset question with "I think it is a reset." Management pointed to bookings — "the bookings is the biggest thing that gives us confidence" — as its principal support, and gave qualitative answers without figures on data-center margin, Simpcore's growth rate, and pull-through timing.
Management Guidance
On 2026-08-05 management raised FY2026 revenue guidance to $760–790M from $730–760M and cut adjusted EBITDA to $78–84M from $90–94M. Total gross margin was cut to 23–24% from 26–27%. Total organic growth was raised to 9–14% while ODR organic growth was lowered to 6–10%, and SG&A was guided to 15–16% of revenue. Free cash flow conversion is guided to at least 75% of adjusted EBITDA, with CapEx at about a $5M run rate. The revised guidance excludes any contribution from Simpcore or future acquisitions. Separately, management guided Simpcore to $12M of program-management revenue and $4M of adjusted EBITDA in 2027, and targeted company-average gross margin for Pioneer Power within two to three years.
Trajectory
Reported revenue has climbed but the mix has shifted to acquisitions. Q2 2026 revenue was $173.5M, up 21.9% from $142.2M a year earlier, yet $30.9M of that came from Pioneer Power while organic ODR revenue fell 3.4% — a second consecutive quarterly decline after a 5.4% drop in Q1 2026. Gross margin compressed year over year from 28.0% to 21.5%, and adjusted EBITDA margin from 12.6% to 8.0%. Management attributes the organic softness to a Q3 2025 booking gap and the margin pressure to Pioneer Power's lower margin profile, fixed-cost absorption, and data-center-linked competition for skilled labor and materials. Bookings have stayed above revenue for three quarters but decelerated across them: $225M, then $209M, then $182M.
The Model
The model's locked projections put FY+1 revenue at $780M with EBITDA of $71M, a 9.15% margin, and FY+2 revenue at $860.0M with EBITDA of $90M, a 10.5% margin. The FY+1 revenue figure sits near the top of management's raised FY2026 guidance range of $760–790M. The projections show revenue continuing to grow and EBITDA margin expanding from FY+1 to FY+2, with FY+1 anchored to the current guide and the booking wave converting, and FY+2 carrying the further step up in both lines.
| Metric | FY2025 | Next FY (E) | Following FY (E) |
|---|---|---|---|
| Revenue | $647M | $780M | $860M |
| YoY Growth | — | +20.6% | +10.3% |
| EBITDA | $67M | $71M | $90M |
| EBITDA Margin | 10.4% | 9.2% | 10.5% |
Projections are the median of 5 independent model runs. The model’s revenue sits 9.6% above analyst consensus.
On 2026-08-05 management raised FY2026 revenue guidance to $760–790M from $730–760M and cut adjusted EBITDA to $78–84M from $90–94M. Total gross margin was cut to 23–24% from 26–27%. Total organic growth was raised to 9–14% while ODR organic growth was lowered to 6–10%, and SG&A was guided to 15–16% of revenue. Free cash flow conversion is guided to at least 75% of adjusted EBITDA, with CapEx at about a $5M run rate. The revised guidance excludes any contribution from Simpcore or future acquisitions. Separately, management guided Simpcore to $12M of program-management revenue and $4M of adjusted EBITDA in 2027, and targeted company-average gross margin for Pioneer Power within two to three years.
What Could Go Right — and Wrong
- The rebuilt GCR backlog converts at better margins, lifting GCR gross margin back above the 14.5% Q2 print.
- Simpcore's oversight of more than $8B in customer project budgets converts into Limbach bookings, following the 20x healthcare pull-through precedent.
- Healthcare demand turns, removing the largest drag on owner-direct revenue and margin.
- Pioneer Power reaches company-average gross margin ahead of the stated two-to-three-year window.
- Data-center bookings repeat at or above the ~27% share seen in Q1 2026, and management discloses a data-center revenue percentage.
- GCR gross margin stays near Q2's 14.5% even as the rebuilt backlog converts, contradicting the "timing, not execution" explanation.
- The 23–24% gross-margin guide proves to be a new base rather than a trough, and a second guide cut follows.
- Organic revenue stays negative, leaving reported growth dependent on acquisitions and a limited balance sheet.
- Data-center awards fail to repeat; management has said it lacks "enough quarters in a row" to establish a cadence.
- The securities investigations convert to filed actions, or the 2026-09-09 8-K proves to be more than routine acquisition financing.
Looking Ahead
Over the next 12 months the tests are margin and conversion. The company has to show the rebuilt GCR backlog converting at better margins, the raised 9–14% organic-growth guide materializing after two negative quarters, and Simpcore's overseen budgets turning into bookings. It also carries an accelerating acquisition cadence — Simpcore closed 2026-08-04 and 1901 Inc. on 2026-09-01 — against a profit guide it has already cut once.
- Q3 2026Q3 2026 earnings call — First test of the GCR margin "timing" claim and the organic-growth guide.
- Undated2026-09-09 8-K detail — Material agreement signed and terminated plus new debt; no detail given.
- 2027Simpcore 2027 targets — Guided to $12M program-management revenue and $4M adjusted EBITDA.
- 2027GCR margin recovery — Management flags possible margin benefit as the rebuilt backlog converts.
- Next call1901 Inc. contribution — Whether the Madison, Wisconsin acquisition gets contribution guidance.
Financials
Annual Summary
| Metric | FY2024 | FY2025 | TTM | YoY |
|---|---|---|---|---|
| Revenue | $519M | $647M | $684M | +24.7% |
| Gross Margin | 27.7% | 26.4% | 23.6% | 132bps |
| EBITDA | $50M | $67M | $58M | +33.7% |
| EBITDA Margin | 9.7% | 10.4% | 8.5% | +71bps |
| Net Income | $31M | $39M | $30M | +26.5% |
| Free Cash Flow | $29M | $42M | $51M | — |
| Net Cash | — | — | — | — |
Key Ratios (Trailing)
- P/E TTM—
- EV/EBITDA TTM—
- EV/Revenue TTM—
- Price/FCF TTM—
- Gross Margin (TTM)23.6%
- EBITDA Margin (TTM)8.5%
- Net Margin (TTM)4.4%
- ROIC12.6%
- FCF Conversion87.5%
- SBC / Revenue1.1%
The Company
Limbach is a building systems solutions firm that designs, delivers, and maintains mechanical, electrical, plumbing, and controls — MEPC — systems. It partners with building owners and operators of mission-critical facilities across healthcare, industrial, data centers, life sciences, higher education, and cultural and entertainment markets. The 10-K describes approximately 1,500 team members across 21 offices in the Eastern and Midwestern U.S., integrating engineering expertise with field execution to provide customized MEPC infrastructure solutions.
The company reports in two segments. Owner Direct Relationships, or ODR, covers owner-direct projects, maintenance, and specialty contracting for building owners and operators, including service, maintenance, retrofit, rental equipment, infrastructure upgrades, and energy efficiency work; it was 74% of Q2 2026 revenue. General Contractor Relationships, or GCR, covers new construction or renovation MEPC projects awarded by general contractors or construction managers; it was about 26% of Q2 2026 revenue. Limbach owns an approximately 40,000 square-foot facility in Woodbury, Minnesota used for operations, fabrication, warehousing, and offices, and operates an almost 14-acre fabrication facility in Chattanooga acquired with Jake Marshall in late 2021. Management describes the business as heavily weighted toward institutional and industrial markets, with healthcare a core owner-direct vertical.
Business Segments
Competitive Landscape
Limbach competes in MEPC contracting. Its 10-Q states the company aims to differentiate itself by being a single-source provider for building owners. Management points to its almost 14-acre Chattanooga fabrication facility as an advantage when competitors are "filled up," and to combined local and national execution — "the ability to have local and national, I think, is going to be a game changer." The company also describes itself as "under indexed from a data center perspective."
- APi Group (APG)Listed as an inferred competitor in the supply-chain wiring file, described as a mechanical/MEPC contractor serving data centers; no company disclosure.
- EMCOR (EME)Listed as an inferred competitor in the supply-chain wiring file and also appears there as an inferred customer ("mechanical-contracting"); no company disclosure.
- Comfort Systems USA (FIX)Listed as an inferred competitor in the supply-chain wiring file and also appears there as an inferred customer; no company disclosure.
Supply Chain
Limbach sits in the construction layer of the data-center build-out, buying equipment and materials and installing MEPC systems for owners. Its supplier and customer links in the supply-chain file are all inferred, with zero documented quotes, and no neighbor in the read-through packet names Limbach.
More on LMB: Earnings recap