the use of high-strength beams glued from several pieces of spruce wood

struts rod tensioner snow anchor architecture background beam bolt carpenter concrete connection construction detail foundation frame girder glue glued gray hand holding inserted inside joint kvh landscape lookout mesh metal notch outdoor park patio pergola pillar prism screw screwing spruce steel strut tightening timber tower washer wood wooden work worker use high-strength beams pieces twist suitable pergolas towers buildings large screws post