Timothy Boswell
Analyst · Morgan Stanley
Thank you, Brad. Please turn to Slide 12, and we'll go through the financial results in a bit more detail. We had no shortage of excitement in Q3, with continued strong organic growth, substantial completion of the Acton Mobile integration other than real estate consolidation and the financing activities associated with the closing of the ModSpace acquisition.
As Brad mentioned, our increased guidance on October 1 reflects our enthusiasm regarding the trajectory of the business. In the top-left chart, total revenues were up 88% year-over-year, with growth in both segments driven by 3 factors: first, organic growth in the legacy WillScot U.S. segment; the acquisition of Acton Mobile at the end of 2017; and 1 and 1.5 months of contribution from ModSpace after closing that acquisition in the middle of the quarter on August 15, 2018.
On the bottom chart, we present a pro forma revenue bridge to capture the organic performance of the combined portfolio. Revenues were up $31 million or 11.6% year-over-year as if we had owned ModSpace, Acton and Tyson in the prior year and with the majority of the growth coming from average rental rates in the U.S. across the combined portfolio. In the top-right chart, adjusted EBITDA of $64.6 million in the quarter was up 100.6% versus prior year, and our adjusted EBITDA margin percentage expanded by 185 basis points to 29.5%.
As you will recall, with the Acton acquisition, we operated the business in parallel to WillScot with a duplicative cost structure for the first full quarter post closing until integration actions began to flow through our financial results, which we saw in Q2 this year, and having closed ModSpace on August 15, we expect this same phenomenon through late Q4 this year or early 2019 with further margin expansion as cost and revenue synergies build throughout 2019.
Obviously, the $65 million of adjusted EBITDA in Q3 only includes 1 and 1.5 months contribution from ModSpace, so we are confident our reported results will accelerate significantly again in Q4, delivering the guidance range for 2018 that Brad articulated earlier and setting up our run rate for 2019.
Turning to Slide 13. Key trends in our U.S. Modular leasing business continue to be extremely favorable. As was the case in prior quarters due to our acquisition activity, we've included our units on rent and average monthly rental rate on the left-hand side as they appear in our financial statements.
On the right, we've presented the same metrics as if we had owned Tyson, Acton and now ModSpace for all periods. I'm going to focus on the right-hand pro forma charts because they better illustrate the trends we see heading into the remainder of the year.
On the top-right chart, average modular space units on rent increased to 87,000 in Q3 2018, with utilization up 310 basis points across the combined WillScot fleet. While the year-over-year pro forma unit on rent growth is below our 1% to 3% target range, the as-reported volume growth of 88% year-over-year on the top-left side of the page as well as Brad's comments on the integration progress are a good reminder of the transformation underway in the business.
The bottom charts look at average monthly rental rates, both as reported and pro forma for our acquisition activity, and we continue to show tremendous traction with rate growth again accelerating in Q3.
On the bottom-right chart, average monthly rental rate increased 13.4% year-over-year and 4% sequentially to $549 per modular spacing on rent in Q3 2018. Of the 13.4% year-over-year increase, approximately 60% was driven by unit rates and the other 40% related to vast rate and penetration. This has been one pleasant surprise as we've gotten deeper into the integration. The ModSpace team had been doing a great job accelerating rate growth in their business, and we believe the application of our rate optimization tools, which ModSpace was actually beginning to implement themselves, will continue to capture revenue leakage across the acquired portfolios.
We have previously quantified the embedded vast revenue opportunity, which is north of $125 million and plays out over the next 3 to 5 years organically, irrespective of market conditions. And this Q3 result, combined with the 4 consecutive quarters of accelerating double-digit rate growth, gives us further confidence on these points.
Slide 14 shows our quarterly revenue and adjusted EBITDA from the U.S. Modular segment. In the top-left chart, same as last quarter, our reported revenue is shown in green and the pro forma revenue contribution from Tyson, Acton and ModSpace is in the white boxes. Third quarter revenue in the top-left chart grew 90.5% to $197.6 million versus Q3 2017. The quarter is also up 13.7% versus prior year on a pro forma basis due to aforementioned traction on average rental rates and value-added products as well as a significant ModSpace sale project that completed in the quarter. Adjusted EBITDA for the U.S. Modular segment increased 99% to $58 million in the quarter, with adjusted EBITDA margins up 2 percentage points year-over-year but down slightly sequentially from Q2 due in part to the higher contribution of lower-margin sale revenue as well as the duplicative infrastructure discussed earlier.
Moving to Slide 15, we'll look at the other North America segment, which includes operations in Canada, Alaska and Mexico. In contrast to prior quarters, we are now showing pro forma metrics in Q3 for this segment since ModSpace had a significant presence in Canada.
Before jumping into the charts, I'll remind everyone that, in Q2, we highlighted the stability and frankly, modest improvements in average units on rent and rental rate in this segment, which had begun to show sustainable adjusted EBITDA growth and margin expansion in our leasing operations.
ModSpace's Canadian operations had exposure to upstream oil and gas projects in Western Canada, similar to that of Williams Scotsman. Our ModSpace is the last project -- major project recently terminated over the past several quarters, whereas Williams Scotsman's legacy business bottomed over 12 months ago and has since enjoyed a modest recovery. Average units on rent in the bottom right-hand chart here best illustrates this dynamic. You can see WillScot legacy units on rent, in green, bottoming in Q1 2017, followed by sixth consecutive quarters of sequential growth. ModSpace's units on rent, in white, totaled 3,615 units in Q3, which was down 710 units or 16% versus Q3 2017. When combined with WillScot, pro forma units on rent are down 3.6% year-over-year but stable sequentially. And you can see average rental rates in the top-right chart are also trending favorably, both sequentially and year-over-year. Including the contribution from ModSpace for 1.5 of the quarter, overall segment revenue increased 68% to $21.3 million, and adjusted EBITDA increased to 114% to $6.2 million in Q3, with 4 percentage points of margin expansion sequentially from Q2. Revenue and adjusted EBITDA will obviously increase again in Q4 as the full contribution of ModSpace flows through in that quarter.
Turning to Slide 16. This is our usual reconciliation of net income to adjusted EBITDA. As we have discussed in prior quarters, our ambitious consolidation activity does come with onetime transaction in integration costs, which totaled approximately $45 million in Q3, and it's useful to understand the drivers of these costs. First, please note that interest expense of $43.4 million, as reported in our financial statements, includes $20.5 million of onetime commitment fees related to the financing of the ModSpace acquisition that were expensed in the period and are not recurring in nature. Similarly, there were $10.7 million of other onetime transaction costs expensed in the period related to the ModSpace acquisition.
As discussed in prior quarters, we are incurring restructuring and integration costs, which totaled $6.1 million and $7.5 million, respectively, in Q3, related to the operational execution of the Acton and ModSpace integrations. We have incurred approximately $22 million year-to-date of the approximately $60 million that we estimated for the combined Acton and ModSpace integrations, and we expect to incur the remainder over the course of the next 4 to 5 quarters. Together, that totals $31.2 million of transaction-related expenses and $13.6 million of integration-related expenses that are outside the normal course of our operations. Obviously, we expect this reconciliation to simplify and the net income picture to improve significantly as transaction and integration costs subside and synergies are realized in coming quarters.
Turning to Slide 17, we'll look at capital spending and operating free cash flow. In the top chart, we had gross CapEx in the quarter of $48 million, which is up approximately 85% year-over-year. As a reminder, that spend is supporting modular units on rent that are up 88% year-over-year in our U.S. business as well as continued expansion of value-added products and services. So the increase is roughly proportional to the increased scale of our portfolio prior to any synergy realization, given the limited ownership period of ModSpace in Q3.
Even with the limited opportunity for synergy realization, adjusted EBITDA less CapEx more than doubled to $22 million year-over-year, and we expect to improve upon this operational free cash flow in coming quarters. As a reminder with the spend, we are not expanding the fleet. Excluding acquisitions, total unit count was down 2%, and rental equipment net book value was essentially flat versus Q1 2018 on a pro forma basis. So strategically, we're allocating this spend to grow units on rent and tighten utilization through refurbishments of assets we already own, supplemented with targeted new fleet purchases as well as growing value-added products and services. The WillScot spend in Q3 reflects the strategy with approximately 50% of gross CapEx going to refurbishments and the remainder evenly split between value-added products and new fleet purchases. We believe this is the most capital-efficient way to grow the business when coupled with our M&A strategy. As we've said before, we'll continue to assess our capital deployment on a quarterly basis. And in the short term, given our business model, our capital investments are almost entirely discretionary.
Moving to Slide 18. As mentioned previously, we executed quite a lot of debt and equity financing activity in Q3, all in relation to our $1.2 billion acquisition of ModSpace. We issued $300 million of new 2023 senior secured notes at 6.875%, we issued $200 million of new 2023 senior unsecured notes, and we extended our ABL to $1.425 billion into approximately $470 million to fund the remaining cash consideration for the ModSpace acquisition.
Note, the ABL bears interest at LIBOR plus 250, and we had a weighted average interest rate of 4.65% in Q3.
On November 6, we entered into an interest rate swap, whereby we will pay a fixed rate of 3.06% and receive 1-month LIBOR on $400 million of notional value through the maturity of the ABL in May 2022. Based on our September 30 debt balances and including the swap, our debt is approximately 70% fixed rate and 30% floating, and our weighted average cost of debt inclusive of the swap is approximately 6.5%.
As Brad mentioned, our total net leverage ratio is 4.6x pursuant to the definitions in our credit agreement, which provides for the pro forma inclusion of ModSpace and Acton, inclusive of cost synergies and other actions to be taken in the coming months. To -- while we've flexed above our target leverage range for the purposes of consummating the ModSpace deal, we are very comfortable, given the embedded growth in the portfolio, with our ability to delever back to 4x in the next 18 months.
While not directly related to our debt structure, I will mention, as a reminder, we issued 9.2 million new Class A common shares, raising $139 million net of underwriters discount to fund a portion of the cash consideration in the ModSpace transaction and issued 6.5 million Class A common shares as well as ones to purchase 10 million common shares to former ModSpace shareholders, as noncash consideration is part of the purchase. Please see Page 27 in the appendix of -- for a share breakdown, as of September 30, post these issuances.
And lastly, before I hand it back to Brad, yesterday, we launched an exchange offer, which gives holders of certain of our warrants the opportunity to exchange their warrants into common stock on a cashless basis at a ratio of 0.18182 shares per warrant. The warrants eligible for the offer are the public and private warrants issued at the IPO of Double Eagle Acquisition Corporation in 2015, which have an effective exercise price of $11.50 per full underlying share. There are approximately 69.5 million of such warrants outstanding, each exercisable for 1/2 of 1 share. This provides an opportunity for warrant holders to realize value and increase liquidity by moving over to WillScot common stock, and we expect that exchange offer will expire on December 6. Given it's a ongoing securities offering, we're not going to comment much more on that topic today.
With that, I'll hand it back to Brad for closing comments and then Q&A. Brad?