Thomas Hill
Chairman, President and Chief Executive Officer at Vulcan Materials
Thank you, Mark, and thanks to everyone for joining the call this morning. We appreciate your interest in Vulcan Materials Company and hope that you and your families continue to be safe and healthy. As you will have seen from the press release this morning, Suzanne is decided to retire in September to spend some well reserve time with her family. I'll have more to say on this at the conclusion of our prepared remarks.
Now, let's move to our fourth quarter performance and Suzanne will cover the full year performance later on. I want to thank our team for its strong execution during the fourth quarter. Our financial results were ahead of expectations despite ongoing challenges from inflationary pressures, particularly in energy and labor constraints. Focusing on our operating disciplines and proactive pricing actions we once again saw expansion in our industry-leading unit profitability. At the same time, we made excellent progress on integrating U.S. Concrete into our business. This overall strong finish to the year allows us to carry considerable momentum into 2022.
We generated $383 million of adjusted EBITDA this quarter, an increase of 23% over 2021. Energy-related inflation was the most significant impact to our business with $36 million worth of higher costs, of which $17 million related to diesel fuel, while the remainder related to liquid asphalt and natural gas. Labor pressures caused higher labor costs due to over time. In the face of these challenges, we were able -- still able to manage our controllable costs well. Aggregates cash unit cost of sales increased less than 1% as compared to the prior year's fourth quarter. This was an excellent operating performance, and I'd like to thank all of our operators and congratulate them on a job well done in 2021 and all the while delivering a world-class safety performance.
Our operating performance helped us improve aggregates cash gross profit per ton by 6% to $7.41. This result includes an $8 million acquisition-related impact for selling acquired material after its mark-up to fair value. Importantly, this progress on cash unit margin expansion represents the 14th consecutive quarter of improvement. We achieved this by consistently executing on our four strategic disciplines, which helped to drive volume growth, higher pricing and improved operating efficiencies. These strategic disciplines will help us take advantage of the favorable demand and pricing environment in 2022.
Total aggregates volume including U.S. Concrete increased by 13% versus last year's quarter. On a same-store basis, volume was up 7%. This reflects, not only continued improvement in demand across all end markets, but also favorable weather in November and December. The aggregates pricing environment continues to strengthen across our footprint. Same-store prices were up 3.7% in the quarter as compared to the prior year and mix adjusted prices increased by 4.2%. Year-over-year, mix adjusted pricing sequentially improve throughout the year having started at 1.3% in the first quarter.
The pricing actions taken to date along with better demand visibility set the stage for a favorable pricing environment in 2022. Asphalt gross profit was $4 million in the quarter compared to $17 million last year as a 35% increase in liquid asphalt cost created a $17 million headwind for us. As we discussed before, liquid asphalt costs were at three-year lows in 2020 and a significant fluctuation of these costs have made for a more difficult comp year-over-year. The good news is that our selling price for asphalt mix increased 5% from the prior year quarter. Through 2022 as pricing catches up we will work to get back to asphalt segments long term averages in terms of margins.
Concrete's gross profit grew from $9 million to $22 million in the fourth quarter. This increase was due to the acquisition combined with higher shipments and price growth in our legacy business. Results were negatively impacted by higher diesel prices and the availability of drivers. Before we move on to the overall demand environment, I'll comment briefly on U.S. Concrete. We continue to be excited about this acquisition and how it expands our footprint. It naturally complements our existing aggregates business in California, Texas and Virginia and gives us access to new platforms in the Northeast. We moved immediately following the acquisition to begin securing cost savings and synergy opportunities.
As I mentioned previously, the integration is going well and our progress accelerated during the fourth quarter with both -- from both operational and back office standpoint. I am pleased with how the business and management teams have blended seamlessly during the first four months of ownership. We remain confident in our ability to generate at least $50 million of initial synergies -- of initial cost synergies on a 12-month run basis beginning mid-year.
Now, I'll touch briefly on the demand picture, which is increasingly positive. The key takeaway is that for the first time in many years all four end-users are expected to grow. The residential end use has continued to show growth in starts in both single family and multifamily housing and we expect starts to continue at these higher levels. Non-residential starts continue to strengthen over a broader range of categories, improving non-residential demand will be positive and help drive growth in our aggregates and our concrete businesses.
On the public side, growth is expected in both highways and other infrastructure. The recently enacted infrastructure investment in Jobs Act will add to existing demand as well as a long getting cycle. Having said that, we do not expect it to have a significant impact in 2022. We are well positioned in the attractive growth markets we serve and those markets are poised to benefit greatly from the legislation in coming years.
Before I turn the call over to Suzanne, I want to reiterate our confidence in our prospects for 2022, particularly with respect to demand visibility, pricing and our ability to control what we can control. We will be mindful of potential pressures from both inflationary trends and tight labor markets. We will continue to focus on our operating excellence and our strategic sourcing disciplines to help offset some of these pressures.
Now, I'll turn the call over to Suzanne for further comments. Suzanne?