On December 18, 2023, the Company’s Board of Directors meeting convened to approve an investment in a project aimed at installing autoclaved aerated concrete production machinery (AAC-2) with a capacity of 163,200 tons per year at the Saraburi factory. The investment budget is approximately 648 million baht, driven by the rising demand for aerated concrete (AAC) products and the insufficient production capacity of AAC in the market.

On June 27, 2022, the Board of Directors’ meeting resolved to approve the investment in installing a concrete roof tile production machine with a capacity of 100,000 tons per year at the Saraburi plant. The investment budget is about 477 million baht because the Company currently uses more than 95 percent of its production capacity.

On July 25, 2022, the Company’s Board of Directors meeting resolved to reduce the registered and paid-up capital of Diamond Materials Co., Ltd. (“Subsidiary”), which the Company holds 99.99 percent of all shares with voting rights of the subsidiary. It reduced the share value by 50 baht per share, totaling 100,000,000 baht from the original registered and paid-up capital of 200,000,000 baht. It is divided into 2,000,000 shares with a par value of 100 baht per share, which is registered and paid-up capital of 100,000,000 baht, and divided into 2,000,000 shares with a par value of 50 baht per share. The Company has completely registered the reduction of registered capital with the Ministry of Commerce on October 25, 2022.

On January 25, 2021, a meeting of the Board of Directors of the Company resolved to approve the restructuring of management and appointment of new executives of the Company with effect from February 1, 2021, making the list of the Company’s executives as follows:

1. Mr. Satid Sudbuntad, Chief Executive Officer and Management Committee Chairman
2. Mr. Sunthorn Suwannajade, Assistant Chief Executive Officer Production and Engineering and Management Committee Member
3. Ms. Peachayanant Lorvoralak, Assistant Chief Executive Officer Sales and Marketing and Management Committee Member
4. Mr. Krit Kullertprasert, Assistant Chief Executive Officer Central Management (CFO) and Management Committee Member
5. Mr. Kamchub Vatanatham, Division Manager (Senior) Sales and Marketing
6. Mr. Somkuan Sittichoketum, Division Manager (Senior) Production and Engineering
7. Mr. Seree Saengmark, Division Manager (Senior) Production and Engineering
8. Mr. Songkran Suwanmak, Division Manager (Senior) Central Management

On April 23, 2021, the 36^th Annual General Meeting of Shareholders (Year 2021) passed a resolution approving the reduction of the Company’s registered capital in the amount of 92,928,700 baht from the original registered capital of 947,961,800 baht to a new registered capital of 855,033,100 baht, divided into 855,033,100 ordinary shares with a par value of 1 baht per share by eliminating the unissued treasury shares according to the share repurchase program for financial management as well as amended the Company’s Memorandum of Association, Clause 4 of the Company to be in line with the reduction of registered capital whereas the Company had completed the register of the reduction of registered capital and the amendment of Clause 4 of the Company’s Memorandum of Association with the Ministry of Commerce completely on May 7, 2021.

On December 13, 2021, a meeting of the Company’s Board of Directors resolved to appoint Mr. Krit Kullertprasert, Assistant Chief Executive Officer, Central Management, to serve for another position as Company Secretary from January 1, 2022. It is due to Ms. Thanakarn Phanthaphirat’s resignation as Company Secretary, effective from December 31, 2021.

The Board of Directors’ Meeting No. 335 on March 23, 2020, with the resolution approval of a project to buy ordinary shares (Treasury Stock) for financial management within the amount not exceeding 517,000,000 baht and number of shares not exceeding 9.92% of the issued and paid-up shares equivalent to 94,000,000 shares. As of May 26, 2020, the Company bought back a total of 92,928,700 ordinary shares equivalent to the repurchased amount of 511,961,400.11 baht. Such repurchased shares have a period of time to sell the shares back to third parties after 6 months from the completion of the share repurchase, but not more than 3 years. The Company had set a period of sale of repurchased shares from 27 November 2020 to 31 December 2020.

On December 18, 2020, the fiber cement production line (NT11) was operated for the production of synthetic wood and diamond board for commercial sale with the total investment budget of 374.54 million baht, which is 6.37 percent lower than the estimate.

On March 18,2019, the Board of Directors resolved to approve the 400 million baht investment in the fiber cement production line (NT11) with the production capacity of 55,000 tons per year at Saraburi Plant since the current production line was utilized over 90 percent of the production capacity.

On June 24,2019, the Board of Directors resolved to appoint two new executives: Assistant Chief Executive Officer and Management Committee Member which effective since July 1, 2019 , namely;
1. Mr. Sunthorn Suwannajad: Assistant Chief Executive Officer Production and Engineering and Management Commitee Member.
2. Ms. Peachayanant Lorvoralak: Assistant Chief Executive Officer Sales and Marketing and Management Commitee Member.

On April 24, 2018, the 33^rdAnnual General Meeting of Shareholders (Year 2018) passed a resolution approving the reduction of the Company’s registered capital in the amount of 99,996,200 baht from the original registered capital of 1,047,958,000 baht to a new registered capital of 947,961,800 baht, divided into 947,961,800 ordinary shares with a par value of 1 baht per share by eliminating the unissued treasury shares according to the share repurchase program for financial management as well as amended the Company’s Memorandum of Association, Clause 4 of the Company to be in line with the reduction of registered capital whereas the Company had completed the register of the reduction of registered capital and the amendment of Clause 4 of the Company’s Memorandum of Association with the Ministry of Commerce completely on May 18, 2018.

Commencement of the truss production line for commercial selling on December 1, 2017, with the investing budget of Baht 9.53 million.

The Board of Directors’ Meeting No. 308 dated December 18, 2017 resolved to appoint Mr. Satid Sudbuntad as Chief Executive Officer (currently the Managing Director) due to the retirement of Mr. Asanee Chantong, effective from January 1, 2018 onwards. The meeting also resolved to establish the Production Technology and Innovation Committee as a sub-committee, with its main duties and responsibilities on production technology related aspect, which is a key factor to cost reduction and improved productivity. The Committee’s duty also includes the preparation of work plan related to innovation and new product development for continued competitiveness. With directions as assigned by the Board of Directors, the Production Technology and Innovation Committee shall perform its duties from January 1, 2018 onwards.

The Board of Directors’ Meeting No. 289 dated May 23, 2016 approved the Treasury Stock Program for financial management purposes with maximum amount of share repurchase not exceeding Baht 520,000,000 and number of share repurchase not exceeding 9.54 percent of the total paid-up shares or equal to 100,000,000 shares. As at June 30, 2016, the Company had repurchased 99,996,200 ordinary shares for Baht 519,980,240 at Baht 5.20 per share. Such repurchase shares have a 6-month period for the resale of shares from the share repurchase date but not later than 3 years. The Company has set the date for the resale of shares within December 31, 2017.

On April 24, 2015, the 30th Annual General Meeting of Shareholders (Year 2015) had approved the reduction of the registered capital of the Company of Baht 1,692,000 from the previous registered capital of Baht 1,049,650,000 to a new registered capital of Baht 1,047,958,000 divided into 1,047,958,000 ordinary shares at a par value of Baht 1 per share by eliminating 1,692,000 unpaid registered shares and amending Clause 4 of the Company’s Memorandum of Association to coincide with the reduction of the registered capital. The Company completed the registration of the reduction of the registered capital and amendment of Clause 4 of the Company’s Memorandum of Association with the Ministry of Commerce on April 30, 2015.

On February 17, 2014 was the date for the exercise of warrants No.14 with 444,000 ordinary shares being exercised at Baht 1.00 per share totaling Baht 444,000. The Company registered the change of paid-up capital increase with the Ministry of Commerce on February 25, 2014, resulting in an increase in paid-up capital to Baht 1,047,812,000.

เมื่อวันที่ 13 มิถุนายน 2557 เป็นวันใช้สิทธิแปลงสภาพครั้งที่ 15 (ครั้งสุดท้าย) โดยมีการใช้สิทธิซื้อหุ้นสามัญ จำนวน 146,000 หุ้น ราคาหุ้นละ 1.00 บาท คิดเป็นจำนวน 146,000 บาท โดยบริษัทฯ ได้ดำเนินการจดทะเบียนเปลี่ยนแปลง เพิ่มทุนชำระแล้วกับกระทรวงพาณิชย์ เมื่อวันที่ 24 มิถุนายน 2557 ส่งผลให้ทุนจดทะเบียนชำระแล้ว เพิ่มขึ้นเป็น 1,047,958,000 บาท

On February 15, 2013 was the date for the exercise of warrants No.11, 505,000 ordinary shares were exercised at Baht 1.00 per share totaling Baht 505,000. The Company registered the change of paid-up capital increase with the Ministry of Commerce on February 27, 2013, resulting in an increase in paid-up capital to Baht 1,038,609,000.

On February 8, 2013, the Company filed application to register the change of address of Branch Office 2 from 490 Moo 6, Tambon Banped, Amphur Muang, Khon Kaen 40000 to 269 Moo 3, Tambon Samran, Amphur Muang, Khon Kaen 40000, effective from March 1, 2013.

On February 15, 2012 was the date for the exercise of warrants No.8, 2,043,000 ordinary shares were exercised at Baht 1.00 per share totaling Baht 2,043,000. The Company registered the change of paid-up capital increase with the Ministry of Commerce on February 27, 2012, resulting in an increase in paid-up capital to Baht 1,029,000,000.

On June 15, 2012 was the date for the exercise of warrants No.9, 150,000 ordinary shares were exercised at Baht 1.00 per share totaling Baht 150,000. The Company registered the change of paid-up capital increase with the Ministry of Commerce on June 26, 2012, resulting in an increase in paid-up capital to Baht 1,029,150,000.

On October 15, 2012 was the date for the exercise of warrants No.10, 8,954,000 ordinary shares were exercised at Baht 1.00 per share totaling Baht 8,954,000. The Company registered the change of paid-up capital increase with the Ministry of Commerce on October 25, 2012, resulting in an increase in paid-up capital to Baht 1,038,104,000.

The Board of Directors' Meeting No. 245 dated October 17, 2012 resolved to change the directors whom are authorized to sign on behalf of the Company, which previously required two of six directors to co-sign and affix with the Company's seal. It was changed to two of seven directors to co-sign and affix with the Company's seal with addition of Mr. Maitree Tawonatiwasna as a director. The change of authorized signatories was registered with the Registrar of Public Company Limited, Department of Business Development, Ministry of Commerce, on October 17, 2012.

The Extraordinary General Meeting of Shareholders No. 1/2011 dated January 12, 2011 resolved to approve for the change of the Company's name from "Diamond Roofing Tiles Public Company Limited" to "Diamond Building Products Public Company Limited" and resolved to approve for the change of Company's stamp, Articles of Association and Memorandum of Association of the Company in order to be in line with the change of Company's name, as well as, approve for the appointment of 3 additional Directors as follows:

1. Mr. Maitree Tawonatiwasna proposed for appointment as the Director
2. Mr. Krit Phanratanamala proposed for appointment as the Director
3. Mr. Woodthikrai Soatthiyanon proposed for appointment as Independent Director

• On February 15, 2011 was the date for the exercise of warrants No.5, 2,236,300 ordinary shares were exercised at Baht 1.00 per share totaling Baht 2,236,300. The Company registered the change of paid-up capital increase with the Ministry of Commerce on February 25, 2011, resulting in an increase in paid-up capital to Baht 1,016,568,000.
• The Board of Directors' Meeting No. 225 dated January 31, 2011 resolved to approve the signing of the contract for the procurement of machinery for the production of non-asbestos fiber cement board (NT-10 Project) with MFL Faserzementanlagen Ges.m.b.H. of Austria. The contract was signed on February 8, 2011. The value of the project is estimated at Baht 480 million. Production is expected to commence in second quarter of 2012.
• The Board of Directors' Meeting No. 226 dated February 26, 2011 resolved to approve the purchase of land with value estimated at Baht 117 million. The land consists of 2 land plots with total area of 145 rai, 3 ngan, 98 wah. The land is located on Mitraphap Road, Tambol Tandiew (Loub lau), Amphur Kaengkhoi, Saraburi Province.

On June 15, 2011 was the date for the exercise of warrants No.6, 2,732,000 ordinary shares were exercised at Baht 1.00 per share totaling Baht 2,732,000. The Company registered the change of paid-up capital increase with the Ministry of Commerce on June 22, 2011, resulting in an increase in paid-up capital to Baht 1,019,300,000.

On July 7, 2011, the Company submitted application for value added tax (VAT) registration for branch office no. 3 located on the new land plot at Mitraphap Road, Tambol Tandiew (Loup lau), Amphur Kaengkhoi, Saraburi Province.

The Board of Directors' Meeting No. 233 dated September 26, 2011 resolved to approve the signing of the contract for the procurement of machinery for the production of autoclaved aerated concrete (AAC Project) with MASA GMBH of Germany. The contract was signed on September 28, 2011. The value of the project is approximately Baht 595 million. Production is expected to commence in the second quarter of 2013.

On October 17, 2011 was the date for the exercise of warrants No.7, 7,657,000 ordinary shares were exercised at Baht 1.00 per share totaling Baht 7,657,000. The Company registered the change of paid-up capital increase with the Ministry of Commerce on October 26, 2011, resulting in an increase in paid-up capital to Baht 1,026,957,000.

On 15th February 2010, the date for the exercise No.2, with the right warrant of 792,000 shares to raise capital of 792,000 Baht from exercising the right on 792,000 shares at 1.00 Baht per share. The Company registered the change of capital increase with the Ministry of Commerce on 25th February 2010 leading to an increase in registered capital to 1,005,966,700 Baht.

On 19th February 2010, The Company organized the Opening Ceremony for the Production Line No. 9 with project investment of Baht 465 million.

On 15th June 2010, the date for the exercise No.3, with the right warrant of 313,000 shares to raise capital of 313,000 Baht from exercising the right on 313,000 shares at 1.00 Baht per share. The Company registered the change of capital increase with the Ministry of Commerce on 24th June 2010 leading to an increase in registered capital to 1,006,279,700 Baht.

The 128th Board of Directors' meeting dated 28th June 2010 has passed a resolution to invest in the installation of the non-asbestos fiber cement board machinery with a production capacity of 72,000 tons per year, having an estimated investment budget of Baht 480 million. The procurement and installation period is approximately 16 months. It is expected that the production of the non-asbestos fiber cement board will be commenced within the 2nd quarter of year 2012.

The 198th Board of Directors' meeting dated 20th October 2008 approved a treasury stock buy back plan for financial management under the total fund of no more than 75,000,000 Baht and shares of no more than 5% of total paid-up shares, which are 50,000,000 shares. As of 30th April 2009, the Company bought back 37,376,800 treasury shares in total with amount of 61,898,914.20 Baht, average price of 1.66 Baht per share. Redemption period for these treasury shares to outside parties shall be within 6 months since the completion of the buy back but no more than 3 years. The Company shall sell these treasury stocks within 2nd May 2012. The Company started reselling of repurchase shares from August 16, 2010 and at end of 2010, the Company has resold a total of 18,475,500 repurchased shares.

On 15th October 2010, the date for the exercise No.4, with the right warrant of 8,052,000 shares to raise capital of 8,052,000 Baht from exercising the right on 8,052,000 shares at 1.00 Baht per share. The Company registered the change of capital increase with the Ministry of Commerce on 26th October 2010 leading to an increase in registered capital to 1,014,331,700 Baht.

บริษัทฯ ซื้อหุ้นสามัญคืนเพิ่มเติมอีกจำนวน 17,967,700 หุ้น จำนวนเงิน 33,960,252.64 บาท ราคาถั่วเฉลี่ย 1.89 บาทต่อหุ้น รวมแล้วบริษัทฯ ซื้อหุ้นสามัญคืนทั้งสิ้น 37,376,800 หุ้น จำนวนเงิน 61,898,914.20 บาท ราคาถัวเฉลี่ย 1.66 บาทต่อหุ้น หุ้นสามัญที่ซื้อคืนดังกล่าวมีกำหนดระยะเวลาจำหน่ายคืนกับบุคคลภายนอกภายใน 6 เดือน นับตั้งแต่การซื้อหุ้นสามัญคืนแล้วเสร็จแต่ไม่เกิน 3 ปี บริษัทฯ ต้องจำหน่ายหุ้นสามัญที่ซื้อคืนภายในวันที่ 2 พฤษภาคม 2555

ที่ประชุมคณะกรรมการบริษัทฯ ครั้งที่ 208 เมื่อวันที่ 31 สิงหาคม 2552 ได้มีมติอนุมัติการจัดสรรใบสำคัญแสดงสิทธิที่จะซื้อหุ้นสามัญของบริษัทฯ โดยไม่คิดมูลค่าให้แก่กรรมการและพนักงานของบริษัทฯ ซึ่งจัดสรรได้ทั้งหมด จำนวน 49,650,000 หน่วย

เมื่อวันที่ 1 ตุลาคม 2552 บริษัทฯ ได้ออกใบสำคัญแสดงสิทธิที่จะซื้อหุ้นสามัญของบริษัทฯ ให้แก่ กรรมการและ พนักงานของบริษัทฯ จำนวน 49,650,000 หน่วย

เมื่อวันที่ 15 ตุลาคม 2552 ซึ่งเป็นวันใช้สิทธิแปลงสภาพครั้งที่ 1 มีกรรมการและพนักงานใช้สิทธิทั้งสิ้น จำนวน 27 ราย โดยมีใบสำคัญแสดงสิทธิที่ขอใช้สิทธิ 5,174,700 หน่วย ในการเพิ่มทุนจากการใช้สิทธิซื้อหุ้นสามัญ จำนวน 5,174,700 หุ้น ราคาหุ้นละ 1 บาทคิดเป็นจำนวน 5,174,700 บาท โดยบริษัทฯ ได้ดำเนินการจดทะเบียนเปลี่ยนแปลงเพิ่มทุนชำระแล้วกับกระทรวงพาณิชย์ เมื่อวันที่ 27 ตุลาคม 2552 ส่งผลให้ทุนจดทะเบียนชำระแล้ว เพิ่มขึ้นเป็น 1,005,174,700 บาท

เปลี่ยนแปลงผู้รับรองระบบมาตรฐานมาเป็น บริษัท ทูฟ นอร์ด (ประเทศไทย) จำกัด (TUV NORD) จากประเทศเยอรมนี (เดิมใช้บริษัท เอสจีเอส (ประเทศไทย) จำกัด (SGS)) ดังนี้

• ISO 9001:2008 : ระบบการบริหารคุณภาพทั้งในระบบส่วนโรงงานและส่วนสำนักงาน
• OHSAS 18001:2007 : ระบบการจัดการอาชีวอนามัยและความปลอดภัย
• ISO 14001:2004 : ระบบการจัดการสิ่งแวดล้อม (ได้รับการรับรองเมื่อวันที่ 22 พฤศจิกายน 2552)

Upgrade การรับรองระบบบริหารงานคุณภาพ ISO 9001:2000 เป็น ISO 9001:2008 และมีการเปลี่ยนนโยบายคุณภาพ

Signing of contract for the purchase of NT-9 production line from MFL Faserzementanlagen Ges.m.b.H of Austria.

The Extraordinary Meeting of Shareholders No. 1/2008 dated June 17, 2008 approved the issuance of 49,650,000 units of warrants to the Directors and/or employees of the Company under the Employee Share Ownership Program and approved the capital increase of Baht 49,650,000 from previous registered capital of Baht 1,000,000,000 (One billion Baht) to become a new registered capital of Baht 1,049,650,000 (One billion, forty nine million, six hundred fifty thousand Baht), all of which are 1,049,650,000 common shares (One billion, forty nine million, six hundred fifty thousand shares) with par value of Baht 1.00 per share and to amend the Article No. 4 of the Company's Memorandum of Association according to the increase of capital.

Completed the increase of capital registration and amended the Article No. 4 of the Company's Memorandum of Association on July 1, 2008.

The Board of Directors' Meeting no. 198, dated October, 20, 2008 approved treasury stock buyback plan to manage capital with the total fund of no more than 75,000,000 Baht and shares not exceeding 5.00% of total paid-up shares, which are 50,000,000 shares. As at the end of 2008, the Company bought 19,409,100 treasury shares worth 27,938,661.56 Baht with average share price of Baht 1.44 per share. 2008 year-end earnings per share increased by 1.98%.

The Board of Director's Meeting no. 197, dated October 6, 2008 approved to establish regional distribution center at Khon Khaen province (HUB), to service customers in the upcountry who do not have a direct access to Saraburi plant. The Company has established its first hub, which would start operation in 2009.

NT8 Siding Board Production Line was completed and ready for commercial production.

The Company has recognized the importance of information technology in order to develop an effective operation and management system by improving all the information technology to the Enterprise Resources Planning (ERP) by choosing the SAP Software ECC6 to replace the previous system. The system with several new functions can support the current and future requirements of the Company for continuous operation and development having information management system in Real Time mode and links within the Company to facilitate quick and accurate management decisions. The new system has been commenced since January 2, 2008.

The Extraordinary Meeting of Shareholders No. 1/2007 dated August 21, 2007 has resolved to approve the change of the Company's share par value from the par value of Baht 5.00 per share to Baht 1.00 per share making the registered share capital of Baht 1,000,000,000 (One billion Baht) divided into 200,000,000 ordinary shares (Two hundred million shares) at a par value of Baht 5 per share to become a new registered share capital of Baht 1,000,000,000 (One billion Baht) divided into 1,000,000,000 ordinary shares (One billion shares) at a par value of Baht 1.00 (One Baht). The Article No. 4 of the Company's Memorandum of Association was amended accordingly on September 4, 2007.

Completion of concrete tile (CT5) production line project and ready for commercial operation.

The opening of NG gas stations for all the production lines, FC, CT and NT.

Signing of tiles sales and purchase contract for the Ua-Atorn Housing Project with Italian-Thai Development Public Company Limited

The Board of Directors' Meeting No. 175 dated November 27, 2006 resolved as follows:

1. 1. To terminate the Board of Executive Directors as of December 31, 2006 and replace it with the Executive Committee, comprising of the Managing Director as the Chairman, and Deputy Managing Director and Assistant Managing Director as the Executive Committee Members that would take effect as of January 1, 2007.
2. 2. To approve the resignation of Mr. Sakda Maneeratchatchai from Director and Managing Director positions due to his retirement, effective from December 31, 2006 and the appointment of Mr. Asanee Chantong as the Director and Managing Director to be effective from January 1, 2007.

The Extraordinary Meeting of Shareholders No. 1/2005 dated January 10, 2005, approved the reduction of the ordinary share's par value from Baht 10 per share to Baht 5 per share and for the Company to offer 40,000,000 newly issued shares to a limited group of individuals and/or the general public domestically and/or internationally, and to proceed with the registration of such ordinary shares with the Stock Exchange of Thailand.

Construction commenced for the additional production lines for concrete tiles (CT5) and for Jearanai tiles (NT8).

The Company received the accreditation standard for Occupational and Environmental Safety (OHSAS18001:1999) from SGS.

The Company started the production and sales of the Jearanai products.

The Company introduced new Jearanai products including shingle roof, board, laths and eaves.

On November 9, 2005, the Securities and Exchange Commission approved the Company's securities to become the listed securities on the Stock Exchange of Thailand.

During November 16-18, 2005, the Company offered 40 million newly issued shares for sales to the general public.

The Company's shares started trading on the Stock Exchange of Thailand on November 29, 2005.

Filing for increase of capital registration with the Department of Business Development.

Introduction of new product which was the flat concrete tile under the brand name of Adamas.

The Extraordinary Meeting of Shareholders No. 2/2004 dated August 24, 2004 resolved to convert the Company's status to a public company limited and to reduce its share par value from Baht 100 per share to Baht 10 per share.

Company name registration with the Department of Business Development as Diamond Roofing Tiles Public Company Limited.

Sale of machinery and equipment for asbestos cement pipe manufacturing to Siam Navatarn Co., Ltd. at a selling price of Baht 10.3 million, which were sold in their existing conditions as the machinery and equipment had not been utilized for a long time.

The Company received the quality assurance ISO 9001:2000 certification from SGS, which was enhanced from the Industrial Standard previously received from the Thai Industrial Standards Institute, Ministry of Industry (since 1998).

Sale of PVC pipe production plant, including machinery and equipment and other fixed assets at the selling price of Baht 82.9 million from a net book value of Baht 74.8 million.

Implementation of production management system development (IMPAC), focusing on production cost reduction and making every employee become aware of the production cost reduction at every step of the process.

Siam City Cement Public Co., Ltd. sold all of its shares in the Company to Myriad Materials Co., Ltd. and other 6 minor shareholders.