Exhibit 99.1

L.B. FOSTER REPORTS FIRST QUARTER OPERATING RESULTS AND PROVIDES 2015 OUTLOOK

PITTSBURGH, PA, May 6, 2015 – L.B. Foster Company (NASDAQ: FSTR), a leading manufacturer, fabricator, and distributor of products and services for rail, construction, energy and utility markets, today reported its first quarter 2015 operating results, including:

First Quarter Results

CEO Comments

Robert P. Bauer, L.B. Foster Company’s President and Chief Executive Officer, commented, “Operating results in Q1 were driven by solid gross margin performance. We realized year over year gross margin improvements in our Tubular and Rail Products businesses which helped drive the 60 basis point improvement to 22.2%. Operating expenses in the quarter were impacted by acquisition costs related to TEW Engineering and IOS, and to a lesser extent Chemtec Energy Services. These three acquisitions were completed in a 90 day period requiring considerable resources for evaluation and closing, with less than a full quarter impact on Q1 sales. Despite the increased expenses, EPS improved 17% to $0.41 per share.”

Mr. Bauer went on to say, “We are very anxious to begin working on the growth programs that these new businesses can bring. Also, the Company restructured its credit facility in Q1 providing the necessary borrowing capacity to complete the acquisitions, while still providing financial flexibility. As such, we finished the quarter with over $218 million of debt. The financial picture of the company is now beginning to reflect the anticipated changes driven by our strategic plan including a more aggressive acquisition strategy and the move into adjacent markets that will provide attractive growth and value creation.”

Q1 Business Segment Highlights

($000’s)

Rail Products and Services Segment

Rail sales increased 5.7% due principally to increases in our Rail Distribution, Allegheny Rail Products and Concrete Tie businesses, partially offset by a decline in Transit Products sales. The 2015 gross profit margin was favorably impacted by improvements in our Rail Distribution, Transit and Allegheny Rail Products businesses.

Construction Products Segment

Construction sales increased by 25.2% in the quarter due to sales improvements across all divisions except for the Bridge Products business. Gross profit margins declined 180 basis points due to reductions in the Bridge Products and Piling divisions.

Tubular and Energy Services Segment

Sales for this segment increased by 146.2% in the quarter due principally to increased revenues from recent acquisitions as well as improved sales of our coatings businesses. Tubular gross profit margins increased due principally to volume-related leverage in our specialty coatings business as well as our recent acquisitions of higher margin businesses.

2015 Outlook

Overall market conditions are expected to be favorable across our business segments in 2015 with the exception of certain areas in the energy market which are likely to experience short term volatility. Capital spending plans for many of the pipeline customers we serve have remained in place, while the E&P firms reduced capital spending aimed at drilling operations appear to have reached a conclusion for 2015. We are also reducing expectations for sales to Union Pacific Railroad based on the ongoing litigation over concrete tie warranty claims. In addition, headwinds from a strong dollar are likely to have a negative impact on sales.

The Company expects 2015 sales to be in the range of $770.0 million to $780.0 million. Pretax income is expected to range between $51.5 million to $53.0 million while diluted EPS is expected to range from $3.20 to $3.30. We forecast EBITDA to be in the range of $84.5 to $86.0 million for the year.

L.B. Foster Company will conduct a conference call and webcast to discuss its first quarter 2015 operating results on Wednesday May 6, 2015 at 11:00 am ET. The call will be hosted by Mr. Robert Bauer, President and Chief Executive Officer. Listen via audio on the L.B. Foster web site: www.lbfoster.com, by accessing the Investor Relations page. The conference call can be accessed by dialing 800-299-9086 and providing access code 11643536.

This release may contain forward-looking statements that involve risks and uncertainties. Statements that do not relate strictly to historical or current facts are forward-looking. When we use the words “believe,” “intend,” “expect,” “may,” “should,” “anticipate,” “could,” “estimate,” “plan,” “predict,” “project,” or their negatives, or other similar expressions, the statements which include those words are usually forward-looking statements. Actual results could differ materially from the results anticipated in any forward-looking statement. Accordingly, investors should not place undue reliance on forward-looking statements as a prediction of actual results. The Company has based these forward-looking statements on current expectations and assumptions about future events. While the Company considers these expectations and assumptions to be reasonable, they are inherently subject to significant business, economic, competitive, regulatory and other risks and uncertainties, most of which are difficult to predict and many of which are beyond the Company’s control. The risks and uncertainties that may affect the operations, performance and results of the Company’s business and forward-looking statements include, but are not limited to, an economic slowdown in the markets we serve; the risk of doing business in international markets; our ability to effectuate our strategy including evaluating potential opportunities such as strategic acquisitions, joint ventures, and other initiatives, and our ability to effectively integrate new businesses and realize anticipated benefits; a decrease in freight or passenger rail traffic; the timeliness and availability of material from our major suppliers; labor disputes; changes in current accounting estimates and their ultimate outcomes; the adequacy of internal and external sources of funds to meet financing needs; the Company’s ability to manage its working capital requirements and indebtedness; domestic and international taxes; foreign currency fluctuations; inflation; domestic and foreign government regulations; sustained declines in energy prices; a lack of state or federal funding for new infrastructure projects; increased regulation including conflict minerals; an increase in manufacturing or material costs; the ultimate number of concrete ties that will have to be replaced pursuant to the previously disclosed product warranty claim of the Union Pacific Railroad and an overall resolution of the

related contract claims as well as the outcome of the lawsuit filed by the UPRR and a reduction of future business with the UPRR; risks inherent in litigation and those matters set forth in Item 8, Footnote 20, “Commitments and Contingent Liabilities” and in Item 1A, “Risk Factors” of the Company’s Form 10-K for the year ended December 31, 2014 as updated by any subsequent Form 10-Qs. The Company urges all interested parties to read these reports to gain a better understanding of the many business and other risks that the Company faces. The forward-looking statements contained in this press release are made only as of the date hereof, and the Company assumes no obligation and does not intend to update or revise these statements, whether as a result of new information, future events or otherwise, except as required by securities laws.

Contact:

L.B. FOSTER COMPANY AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except per share data)

L.B. FOSTER COMPANY AND SUBSIDIARIES

CONDENSED CONSOLIDATED BALANCE SHEETS

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This earnings release contains certain non-GAAP financial measures. These financial measures include earnings before interest, taxes, depreciation and amortization. The Company believes that these non-GAAP measures are useful to investors in order to provide a better understanding of the ongoing operations of the Company’s business. These supplemental financial measures are useful to management and external users to assess financial performance of our assets without regard to financing methods, capital structure or historical cost basis. EBITDA is also a financial measurement that is utilized in the determination of certain compensation programs.

These non-GAAP financial measures are not a substitute for GAAP financial results and should only be considered in conjunction with the Company’s financial information that is presented in accordance with GAAP. Quantitative reconciliations of the GAAP measures are presented below:

L.B. FOSTER COMPANY AND SUBSIDIARIES

Reconciliation of Non-GAAP Financial Measures

(In Thousands)