The word(s) "roof" appears 247 time(s) in 241 verse(s) in Quran in Mohsin Khan translation.

(141) (Allah) will say: "Like this: Our Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) came unto you, but you disregarded them (i.e. you left them, did not think deeply in them, and you turned away from them), and so this Day, you will be neglected (in the Hell-fire, away from Allah's Mercy)."

(142) And thus do We requite him who transgresses beyond bounds [i.e. commits the great sins and disobeys his Lord (Allah) and believes not in His Messengers, and His revealed Books, like this Qur'an], and believes not in the Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) of his Lord; and the torment of the Hereafter is far more severe and more lasting.

(143) They say: "Why does he not bring us a sign (proof) from his Lord?" Has there not come to them the proof of that which is (written) in the former papers [Scriptures, i.e. the Taurat (Torah), and the Injeel (Gospel), about the coming of the Prophet Muhammad صلى الله عليه وسلم]?

(144) And if We had destroyed them with a torment before this (i.e. Messenger Muhammad صلى الله عليه وسلم and the Qur'an), they would surely have said: "Our Lord! If only You had sent us a Messenger, we should certainly have followed Your Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.), before we were humiliated and disgraced."

(145) Nay, they say: "These (revelations of the Qur'an which are revealed to Muhammad صلى الله عليه وسلم) are mixed up false dreams! Nay, he has invented them! - Nay, he is a poet! Let him then bring us an Ayah (sign as a proof) like the ones (Prophets) the former were sent (with)!"

(146) Or have they taken for worship (other) alihah (gods) besides Him? Say: "Bring your proof." This (the Qur'an) is the Reminder for those with me and the Reminder for those before me. But most of them know not the Truth, so they are averse.

(147) And We have made the heaven a roof, safe and well guarded. Yet they turn away from its signs (i.e. sun, moon, winds, clouds, etc.).

(148) Man is created of haste. I will show you My Ayat (torments, proofs, evidence, verses, lessons, signs, revelations, etc.). So ask Me not to hasten (them).

(149) We helped him against the people who denied Our Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.). Verily, they were a people given to evil. So We drowned them all.

(150) Thus have We sent it (this Qur'an) down (to Muhammad صلى الله عليه وسلم) as clear signs, evidence and proofs, and surely, Allah guides whom He wills.