Over the years the school role grew to in excess of 350 pupils and a "temporary" classroom had to be built to accommodate the increase as well as the use of  a room in the Library at Railway Terrace.

They had been most successful at the Pengam and Hengoed County Schools. He had heard people say "He is only from Fochriw," but it was a place very dear to him. From that place, some of the finest men in the country had come. There was one in Australia, holding a high position under the government as controller of mines, and some were headmasters of various intermediate schools, from Pantywaun down to Ystrad Mynach. There was a mining engineer at Fochriw with whom he was at school, and in Yorkshire and Lancashire he had met men from Fochriw who were holding high positions. The topic had been suggested to him by Mr. M. Lewis, Bargoed, on the definition of a school. His definition would be that a school was a nursery for the young people of the nation. He wished the school a successful career, and the memory of that occasion would be with him throughout life. Rev. D. Leyshon Evans said that the building of school was long overdue. Some five years ago he was amongst a party that visited the old school, and decided that a new school should be built, but unfortunately there were delays due to lack of money. Alderman W. Williams said he was glad that Fochriw appreciated the educational facility given to it. This was proved by the number who went to the county schools. Just now, education was suffering as it was impossible to staff the schools as they would like, owing to the shortage of teachers due to them serving in the war. He hoped the present crisis would soon be over, but prospects were not favourable. After the war, I  hope a period of attention to education will follow. This was the 58th schools erected in the eastern part of the county from designs by Mr. Pugh Jones, and every one of them had been within the contract price. Councillor J. H. Charles delivered an address, and Councillor J. Jones presented a certificate of merit from the County Education Committee to Elizabeth Ann Angel, for having attended school for eight years without losing a day. Councillor Ben Hughes, Mr. J. D. Jones, Rev. Isaac Roderick, Rev. J. R. Salmon, Councillor W. J. Giles, Councillor John Edwards, and Rev. R. Jones, Abertysswg, also spoke.

During March 1917 at the Royal Hotel, Bargoed, Messrs. Selwyn Davies, Coggins and Company, offered for sale Fochriw Old Council School and the master's house. The property, which was freehold, is situated on a commanding site opposite the railway station, having a frontage of 240 ft, and containing in the whole, 1760 square yards. It was sold to the Dowlais Co-operative Society for £910. The solicitor for the vendors, the Glamorgan Education Committee, was Mr. T. Mansell Franklen.

During 1962 -3 both the Penybanc and Pantywaun schools closed and the children were bussed to attend the school at Fochriw.

On 1 April 1971 both Infants and Junior schools combined under one Head Teacher to become Fochriw Primary School. A Nursery was opened at Plantation Terrace in 1973.