The incident occurred on Wednesday 28 November between 7pm and 7.15pm at the Crown House car park on Windsor Road.
Officers were called to a fire on the ground floor of the car park. No one was injured, however personal belongings including bags and bedding were destroyed.
Investigating officer PC Vickie Duffty based at Slough police station said: “I am appealing for anyone with information to get in touch.
“If you have information about the incident please report this via the non-emergency police number 101 quoting reference 43180364558 or contact us online.
“If you do not wish to speak to police, please contact the independent charity Crimestoppers on 0800 555 111.”