Depends on the type of construction and how the rack brackets attach, either side mount, corner mount, or surface mount on top.
Most people who are stick building and know that they are going to add a roof rack will put dedicated studs (maybe 1x3 in the flat) to help transfer the load down to the floor and give a decent size "blocking" at the top where the brackets attach.
For sandwich or skeleton construction I would think that that there would be plenty of strength with just a wide band along the profile side of the core, if not dedicated vertical sections left strategically under the mounts.
On a foamie you would almost certainly want to put dedicated studs and spars, or at least a large area of blocking to help distribute the loads.
Last edited by KCStudly
on Thu Feb 05, 2015 9:26 pm, edited 1 time in total.
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