To construct a flat adobe roof, beams of wood were laid to span the building, the ends of which were attached to the tops of the walls.
tə kənstɹˈʌkt ɐ flˈæt ɐdˈoʊbi ɹˈuːf, bˈiːmz ʌv wˈʊd wɜː lˈeɪd tə spˈæn ðə bˈɪldɪŋ, ðɪ ˈɛndz ʌvwˈɪtʃ wɜːɹ ɐtˈætʃt tə ðə tˈɑːps ʌvðə wˈɔːlz.