(1) Glass block shall have horizontal joint reinforcement of two corrosion-resistant bars of not less than 3.76 mm diam or expanded metal strips not less than 75 mm wide,
(a) spaced at vertical intervals of not more than 600 mm for units 190 mm or less in height, and
(b) installed in every horizontal joint for units higher than 190 mm.
(2) Reinforcement required in Sentence (1) shall be lapped not less than 150 mm.