Rav Sadya Gaon, Rashi: It is laziness.

Ibn Ezra, Metzudas David: Atzaltayim refers to lazy hands; it is abbreviated. Ibn Ezra - all words that end like this refer to two - Einayim, Raglayim, Yadayim, Shinayim (for there are two sets of teeth - upper and lower)...

Sanhedrin 7a: When a weaver naps, her basket drops from her head (and people do not know her trade).

Ta'anis 7b: Due to laziness of Yisrael who did not engage in Torah, the hater of (this is a euphemism) Hashem become poor. Ha'Mekareh is Hashem - "ha'Mekareh va'Mayim Aliyosav" (Tehilim 103:4).

Rav Sadya Gaon: Via laziness, the ceiling weakens. Metzudas Tziyon - Yimach is an expression of poverty, like " Ki Yamuch Achicha" (Vayikra 25:25).

Rashi: If one does not fix a small hole in the ceiling, it and what is on it will be lowered. I.e. when Yisrael are lazy in Torah, they melt.

Ibn Ezra #1, Metzudas Tziyon: "Ha'Mekareh" is a noun (the ceiling).

Ibn Ezra #2: Some say that ha'Mekareh is a verb (to make a ceiling), like "ha'Mekareh va'Mayim Aliyosav." It is Pi'el conjugation ¹ ; there should be a Dagesh, just Reish cannot receive a Dagesh. The roofer's laziness made a poor job.

Rashbam: Via the laziness of the house-owner, the walls descend. Ha'Mekareh is the walls, which are the strength (support) of the ceiling. Yimach is like Yinmach.

Ri Kara: One who knows how to make a ceiling, and amidst laziness he does not, in the end he will become poor. Anyone who is lazy in his job, in the end he will become poor.

Rid: Man's laziness - he does not strive to profit - causes his ceiling to ruin.

Seforno: Gevurah and Zerizus are needed to fix the country. This is like a roofer - he will be lowered from his status [of an artisan] via Atzaltayim - two kinds of laziness. (a) The one who brings the wood is lazy, and does not bring it. (b) The roofer delays making the ceiling.

Mesilas Yesharim (Perek 6): Often a man's heart knows his obligation and what is proper to save his Nefesh and his obligation to his Creator, and even so he abandons it, only because heaviness of laziness overpowers him. He says, I will eat a little, or sleep a little, or it is hard to leave my house. I took off my cloak - how will I wear it? It is very hot outside, or very cold or raining, or all other excuses that lazy people are full of them. Amidst this, Torah is abandoned, Avodah is Batel and he abandons his Creator.

Rashi: Rain will drip in the house. [When Yisrael are lazy in Torah,] their house of grandeur is destroyed and poor.

Ibn Ezra: Shiflus Yadayim is poverty. "Yidlof" is like "Delef Tored" (Mishlei 27:15). This is connected to the previous verse, as if it discusses the king and officers who engage in eating. They are lazy to look at matters of the kingdom. There are two results. (a) The kingdom is ruined, just like a house is ruined slowly and the ceiling weakens - "Yimach ha'Mekareh." (b) They do not look to increase money and save it for a time of need - "uv'Shiflus Yadayim."

Rid, Metzudas David: This repeats the beginning of the verse.

Seforno: Via laziness of both of them (the roofer and the one who brings the wood), who do not do their jobs properly, the roof is not proper; water will drip in the house. Similarly, the country is ruined via lack of Zerizus of the king and officers.

Metzudas David: His hands are below. He does not lift them to fix the roof.