וַיִּ֤בֶן אֶת־היצוע [הַיָּצִ֙יעַ֙] עַל־כָּל־הַבַּ֔יִת חָמֵ֥שׁ אַמּ֖וֹת קֽוֹמָת֑וֹ וַיֶּאֱחֹ֥ז אֶת־הַבַּ֖יִת בַּעֲצֵ֥י אֲרָזִֽים׃ (פ)
И он построил истории боковой структуры против всего дома, каждый пять локтей в высоту; и они покоились на доме с кедровой древесиной.
Rashi
Five amohs high. Of each one. Therefore, their total height was fifteen amohs besides the thickness of the ceiling.
Rashi
And he covered the Beis Hamikdosh. That is the upper covering of the roof, and the covering [=והספון] mentioned above that was the ceiling of the upper story.