Sarah Lauber
Analyst · Baird
Thanks, Bob. I'll review our full year consolidated earnings, provide more detail on the fourth quarter segment results, liquidity and the balance sheet. I will close with a look at our 2019 guidance.
As Bob mentioned, due to the hard work of all the Douglas teams, 2018 was a robust year. Full year net sales were a record $524 million, a 10% increase over last year.
Net sales increased due to the strong preseason order period for commercial snow and ice control products plus increased volumes in the Work Truck Solutions segment and price increases across all of our businesses.
The sales increase was partially offset by chassis supply delays for our municipal products, which in turn, delayed our sales and has grown our backlog.
Gross profit for 2018 of $154.9 million or 29.6% of net sales compared to $143.1 million or 30.1% of net sales.
When viewing 2018 results, clearly material inflation was a large impact to all of our businesses. For the year, material inflation was offset by price increases within our businesses. However, in so doing, the gross profit as a percent of sales declined as I just mentioned.
With all of the moving pieces around tariffs and steel and freight inflation, covering the headwinds for the year was a success. However, I'll speak to the fact shortly that the coverage is not always timed perfectly within the quarters.
SG&A expenses for the year were $70 million and increased from $60.9 million recorded in the prior year. SG&A increased due in part to increased spending due to return to average snowfall, mainly variable compensation and advertising.
On a GAAP basis, the change in full year net income and earnings per diluted share is magnified by last year's onetime benefit associated with U.S. tax reform, which totaled $22.5 million or $0.97 per diluted share.
On an adjusted basis, full year adjusted net income of $47.4 million or $2.04 adjusted earnings per diluted share increased from $33.5 million or $1.45 in 2017.
This significant increase is due to the sales strength I just discussed within all businesses, but the increase was partially offset by higher inflation, spending increases as we return to an average snow year and the ongoing impact of chassis supply constraints.
Full year interest expense was $16.9 million, a decrease of $1.4 million as we were able to lower the debt balance resulting from a $30 million prepayment earlier in 2018.
The effective tax rate for 2018 was 21.3% of pretax income compared to a benefit of 4.6% in 2017 due to the changes resulting from U.S. tax reform. The effective tax rate was lower than initially expected in 2018 and also favorably impacted adjusted earnings per share as a result of the 3 items recorded in the third quarter.
Now I'd like to cover our fourth quarter results, which also displayed top line strength compared to last year. For the fourth quarter of 2018, we recorded net sales of $151.8 million, an approximate 10% increase compared to net sales of $138 million in the same period last year.
Gross profit for the quarter was $44.1 million compared to $44.8 million in the corresponding period last year.
As a percentage of net sales, gross profit was 29% compared to 32.5% in the same period of the prior year. As I mentioned on the annual results, material inflation was a significant factor affecting our gross profit as a percent of sales decline. In the fourth quarter, we experienced slightly higher material inflation versus price realized in the quarter, which drove a larger temporary margin impact.
We continue to navigate through external factors associated with tariffs and inflation as we enter 2019. I expect that the temporary margin degradation from the fourth quarter will continue into the first quarter of 2019. However, we fully intend to cover material inflation over the longer term.
SG&A expenses for the quarter were $16.7 million in line with $16.3 million recorded in the fourth quarter last year. We produced adjusted EBITDA of $28.8 million in the fourth quarter compared to $30.3 million for the same period last year. The approximate 5% decrease in adjusted EBITDA is mainly attributed to higher material inflation, as I discussed, but also coupled with an increase in discretionary spending as investments returned towards average levels. As a reminder, in 2017, investments were curtailed due to the low snowfall environment
Turning to net income and earnings per share. On an adjusted basis, fourth quarter net income was $14.4 million or $0.62 per diluted share compared to $12.1 million or $0.53 per diluted share for the fourth quarter of 2017. The improvements are a result of all the dynamics discussed thus far plus the favorable change to our ongoing tax rate in 2018.
Now I'll take a closer look at the segment results for the fourth quarter. Work Truck Attachments recorded revenue of $111.4 million and adjusted EBITDA of $25.3 million compared to revenue and adjusted EBITDA of $103.5 million and $29 million, respectively, in the same period last year.
As we experienced lower-than-average snowfall in the fourth quarter, the increase in revenue mainly stems from higher sales of our municipal products and recently introduced new non-truck commercial snow and ice control products. The decrease in adjusted EBITDA was primarily caused by the material inflation dynamics I discussed, combined with an increase in discretionary spending, which returned towards average levels.
The Work Truck Solutions segment reported revenue of $43.5 million and adjusted EBITDA of $5.3 million. In the same period last year, the segment's revenue and adjusted EBITDA were $41 million and $5.7 million, respectively. Revenue increased based on generally improved demand, while the slight decline in adjusted EBITDA was a by-product of inefficiencies caused by a tight and unpredictable supply chains, along with material inflation. As Bob mentioned, we continued to implement DDMS for both our municipal products and the solutions segment. As we have stated, margins have stabilized in these areas and have sequentially improved in the fourth quarter. Going forward, we expect continued margin improvements during 2019.
Turning to the balance sheet and liquidity figures for full year 2018. Net cash provided in operating activities during 2018 was $58.2 million compared to $66.4 million in the prior year. The decrease was primarily driven by 2 main items. First, we made a $7 million voluntary contribution to our pension plan in order to take advantage of a higher tax deduction. Once this payment was completed, our pension plans were 96% funded, and we expect them to be fully funded by the end of 2019.
Second, as we continued to actively manage through both tightening of supply chains and inflation, we have temporarily increased inventory levels to help ensure delivery times to our customers, and in some cases, opportunistically locking lower prices. Therefore, inventory was $82 million compared to $71.5 million at the end of 2017. As a result, total liquidity, which is comprised of $27.8 million in cash and $94.6 million in borrowing capacity under our revolver, was approximately $122.4 million at the end of 2018 compared to last year's liquidity of $136.4 million.
As Bob also mentioned, we announced an increase to the dividend, the 11th consecutive increase in approximately 9 years. We prioritize our dividend as we look at capital allocation, and we also remain committed to reducing our debt.
Net debt of $278.1 million at year-end is down from $310.8 million at the end of 2017, due to the $30 million prepayment we made early in 2018 to reduce our borrowings.
Also, we are announcing today that based on our robust financial and cash flow performance in 2018, we made an additional $30 million payment on our debt in February of this year. Our net debt leverage ratio has declined from 3.3x last year to 2.8x at the end of this quarter.
Capital expenditures for 2018 totaled $9.7 million, an increase of $2.1 million when compared to 2017 capital expenditures of $7.6 million.
The major factor behind the increase was the expansion of our Kings Park facility for Dejana. This investment is already paying off as we've been able to in-source certain functions, which reduces cost and increases velocity over the long run.
Lastly, accounts receivable at the end of the quarter were $81.5 million compared to $79.1 million last year, mostly due to higher sales this year compared to last.
While 2018 presented our team with some external challenges, we are pleased about this past year's overall results and are very encouraged about the company's prospects for 2019 and beyond.
As you saw in the release, we issued our initial 2019 guidance. We view our guidance at this time of the year to encompass most scenarios, except the tail ends in of the bell curve largely driven by the seasonality of snowfall.
With that, we expect to deliver net sales between $510 million and $570 million, adjusted EBITDA in the range of $90 million to $115 million and adjusted earnings per share between $1.60 and $2.40.
This guidance takes into account several key factors and assumptions. One, what we see as demand in the markets we serve, which is also supported by dealers sentiment and our backlog and order trends. Two, we assume ongoing stability of the overall economy. Three, we assume average snowfall. And lastly, we recognize a similar level of ongoing chassis supply issues that we expect to continue through 2019.
On a more specific note, we expect our effective tax rate to return to the new normal range of 25% to 26%. We believe our 2019 guidance reflects the positive long-term outlook for the company. We are focused on the factors within our control, such as expanding margins in both of our segments during the year through internal execution of DDMS and efficiency gains. Although tampered with the backdrop of chassis supply concerns and material inflation as we enter the year, we are confident that our outlook for 2019 has us well positioned to drive meaningful long-term top and bottom line growth.
With that said, I'll turn the call back over to Bob.