Thank you, Albert, and good morning, everyone. I will start with discussing our consolidated financial results and then go into a more detailed review of our Vinyls and Olefins segment results. Westlake continue to benefit from the strong global supply-demand dynamics and a robust return of global economic activity driving demand for most of our products.
For the first quarter of 2021, we reported net income of $242 million or $1.87 per share compared to net income of $145 million for the first quarter 2020, which included a $62 million tax benefit from the CARES Act. These results are inclusive of the previously mentioned severe winter storm impact of approximately $100 million or $0.61 per share in the first quarter. The $97 million first quarter year-over-year increased net income is a result of higher sales prices and integrated margins for polyethylene and PVC and higher earnings resulting from the strong demand in our downstream building products business. Partially offsetting these increases were lost sales and lower production volumes, elevated maintenance cost, higher feedstock and natural gas fuel cost, all related to the severe winter storm as well as lower sales prices for caustic soda.
While we work quickly to get our facilities back online, our estimates for a loss margin from sales and repair expense are approximately $120 million. We incurred approximately $100 million in the first quarter of 2021 results or approximately $0.61 per share, with the remaining $20 million falling into the second quarter. Of this estimated first quarter impact of $100 million, approximately 75% was related to our Vinyls segment, with the balance affecting our Olefins segment.
First quarter 2021 net income increased by $129 million from fourth quarter 2020 net income of $113 million. The increase in net income was largely attributable to higher sales prices for polyethylene and PVC resin. Offsetting these benefits were lower caustic soda prices and higher feedstock and fuel cost.
Our utilization of the FIFO method of accounting resulted in a favorable pretax impact of approximately $55 million or $0.33 per share compared to what earnings would have been reported under the LIFO method. This is only an estimate and has not been audited.
Now let's move on to discuss the performance of our 2 segments, starting with our Vinyls segment. Throughout the first quarter, we experienced robust global demand for PVC anchored by strong global construction activity.
Our downstream building products business continued to benefit from solid residential construction and repair and remodeling demand. PVC strength was driven by broad-based end market demand, including residential construction, automotive and medical equipment.
While the severe winter storm impacted our production in the quarter, the strong demand for PVC and our downstream building products saw higher sales prices, and we benefited from strong integrated margins during the quarter.
For the first quarter of 2021, Vinyls operating income of $200 million increased $127 million from the prior year period, primarily as a result of higher sales prices and margins for PVC resin and higher sales prices and margins in our downstream building products business. This is partially offset by reduced sales volumes and lost production from the severe winter storm, lower sales prices for caustic soda and higher feedstock and fuel cost.
For the first quarter of 2021, Vinyls operating income increased $34 million from fourth quarter of 2020, primarily the result of higher sales for PVC resin and higher volumes in our downstream building products business. In our Olefins business, robust global demand for packaging and other consumer products expanded our integrated margins in polyethylene.
Our first quarter 2021 operating income of $180 million increased $118 million from the first quarter 2020, driven by strong pricing and improved demand, offset by lower sales volumes resulting from the severe winter storm.
For the first quarter 2021, Olefins operating income increased $158 million from fourth quarter of 2020, primarily due to higher sales prices and margins as well as increased sales volumes, partially offset by higher feedstock and fuel cost.
Next, let's turn our attention to the balance sheet and statement of cash flows. We generated $265 million in cash flows from operations in the first quarter 2021, resulting in total cash and cash equivalents of $1.4 billion.
First quarter 2021 capital expenditures were $141 million. We maintain a long-dated debt maturity profile with a weighted average debt maturity of 14 years, anchoring our investment-grade balance sheet.
Now to address some of your modeling questions.
We expect our effective tax rate for the full year of 2021 to be approximately 23% and a cash tax rate of approximately 19%.
As we stated in our last call, we forecast our capital expenditures for the year to be between $700 million and $800 million.
We are planning for a turnaround of our Petro II ethylene unit to begin in September of this year. This turnaround and associated outage is expected to last approximately 60 days. With that, I'll now turn the call back over to Albert to make some closing comments. Albert?