will never need + verb

English as a Second Language English Vocabulary, Grammar and Idioms
1

If you have the roof sealed now, you will never need do it again.

Is “will never need + verb” grammatical?

2

I would think it’s alright. ‘you will never need do it again’ = you will never need to do it again, under the condition of sentences in questions, negations, etc., need could combine with do.