hi been asked to quote a a garage service area. they are taking everything out so its just floor and 2 metres up the walls. its all small ceramic tiles covered in grease and oil. drainage is not great but i can use squeegees and wet vac. was thinking of pre spraying the whole area with tfr watered down then leave to dwell and wash off with hot water pressure washer. do i need to pre spray? or will the heat just clean it on its own? im going to add tfr on the quote either way. the floor is 400 square metres (20 x 20) and walls are 160 square metres so around 560 square metres. it will take a full day. i would like to use the flat surface cleaner so keep spray low but i cant use to hot water through it as it melts the seal inside bearing head. any ideas? thanks guys