Delaying sajdah tilwaat in Salaah

Q:

1. Zaid recited a sajdah verse in salah, he didn't do sajdah tilaawat straight away but did sajdah tilaawat after reciting a few verses. Is the sajda tilaawat valid?

2. Zaid recited a sajdah verse in salah, he didn't do sajdah tilaawat straight away but did sajdah tilaawat in the second rakaat, is the sajda tilaawat valid?