To solve the problems of a lath-net wire-netting from developed for a non-dismantling left-in-place construction method in the field of lath-net wire- netting form construction methods: that its form sheathing plate must be tightened and batters dismantled for disposal; that in a non-dismantling construction method, which is a left-in-place construction method comprising using deformed reinforcing bars or the like and clamping fittings or the like for sandwiching and clamping the deformed reinforcing bars vertically arranged in parallel, and leaving them in place after placement of concrete, the deformed bars and the clamping fittings are costly excessive for use as consumables to be left in place; and that while plated deformed bars pose no problems, normal black-finished bars may have rusting problems.

A rustproof galvanized U-shaped porous channel is used in place of a conventional deformed reinforcing batter. The back of the channel is brought into intimate contact with the wire-netting portion of a lath net and separators are passed through some of a number of previously bored holes and special nuts 3 are tightened to the threaded portions of the separators. They are left in place without being dismantled to complete construction work.