Sometimes, the prescribed time for performing Salah comes while I am in the house of a non-Muslim. I spread my carpet and perform Salah before them. Is the Salah performed in their houses valid?
Yes, your Salah is valid. May Allah make you more keen on obeying Him, especially by offering the five obligatory prayers in their due times. You should be keen on observing Salah congregationally in Masjids (mosques) as much as you can.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.