He was born circa 1695. His father was Juan de Menchaca, and his mother was Margarita Ximenez de Valdez.
On 28 Jul 1712, he requested a dispensation to marry Feliciana Hernandez in Monclova. They were married in Monclova. He was 17 years old, and the bride was 17 years old. Dispensation source: Guerra, et. al., Index to the Marriage Investigations of the Diocese of Guadalajara, 24-38, p.101.
In 1749, he requested a dispensation to marry Maria de Guadalupe Flores de Abrego in Presidio del Sacramento. He was 54 years old. It was his second marriage. Dispensation source: Guerra, et. al., Index to the Marriage Investigations of the Diocese of Guadalajara, 30-13, p.131.