How far apart should rafters be spaced on pergola if used for training grapevines?

Asked February 18, 2019, 4:06 PM EST

I plan on building a metal pergola to train a total of 2 grape vines. However, i need advise on how far apart the rafters should be spaced and if weather the vines should run perpendicular to the rafters or in line. Plus, do i need slats on top of the rafters? If yes, then how far apart should they be spaced? Also should the rafters run along the longer side of the pergola or the shorter side? The pergola would be 18 ft long by 13 ft wide and 8 ft in height.

Outside United States trellis and training systems building construction

1 Response

You might be better served with you searched the internet for grape pergola and looked at all the designs out there. The main supports seem to be about a foot apart.
To me it does not seem to make a lot of difference if the permanent arms of the vine run with or across the rafters. You will be cutting it back severely every year and the new shoots and fruit will cover the distance between. I would not put another layer above if you want the fruit to hang down and be accessible from below