Leaky Roof Rack. Please Help
We are working on converting a shuttle bus into a home on wheels and part of that includes a roof rack for our 1320 watts of solar. We finally mounted the Unistrut to the roof our bus and now we are having leaking issues, we've gone back and tried to add Sikaflex anywhere we thought water might be getting through but are still finding leaks.
The way we created our rack was by drilling through the frame and inserting a sealant covered bolt with a fender washer into the hole. Then on the outside we used hockey pucks as spacers (except for the rear mounting rails where we needed additional metal spacers between the pucks and the Unistrut to raise the rails above our buses AC). Then we put the Unistrut on top of those, put a square washer on the bolt and then tightened a locknut on top to complete the attachment. We then used lap sealant on top of the bolts and Sikaflex 221 everywhere else(around the pucks, between the pucks and Unistrut, over the metal spacers ect).
We have found definitive leaks in the rear where we used the metal spacers but are also concerned there are more leaks that we just have not yet found or that the water may be leaking into the metal frame in other parts.
Our questions are as follows - Do you think there is a problem with our rack construction?(If so what would you do differently?) What would you do to fix/troubleshoot the leaks? We are seeing some cracking in the roof, could that be caused by the rack/tightening the rack on or us walking on the roof?
Photos attached show the mount design, puck/spacer setup, sealant, interior bolts, and roof cracking.