He is married to Dina Johannesdr van den Boomgaard.
Permission for the marriage has been obtained in Kruiningen on April 11, 1800.Source 1
They got married on April 30, 1800 at Kruiningen.Source 11414. Otr. 11 april, Tr. 30 april, Jan Jansz. de Roo, jm. gebooren en woonende te Krabbendijk, met Dina Johannesdr. van den Boomgaard, jd. gebooren en woonend te Kruiningen.
Kruiningen index ref. trouwen 1671-1810 https://geneaknowhow.net/script/zee/Trouwen%20Kruiningen%201671-1810.pdf