Q. Can one join two beams with plastic zip ties, to use them when placed across the width of a large Suka,(20 ft.), as a base for the schach? Would it be permissible to join them with bolts?
A. Horav Shlomo Miller’s Shlit’a opinion is that it is permitted since it is considered only a “ma’amid dema’amid” or indirect support of the schach with items that cannot be used for schach (plastic zip ties and bolts). The schach rest on the beams, and the beams are joined by the ties. However, the Rov mentioned, that the opinion of the Chazon Ish is to be stringent even on any number of ma’amidim.
(As far as the holes created on the beams for the bolts, the Rov maintains that it does not disqualify the beams for schach.)
Instead of joining the beams with questionable plastic ties (including their strength safety), one may try using triangular beam placement on the corners of the suka, and then continue joining the rest.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a