the silicone would do the job but for it to last properly you would be best off losening the fixings along the laps so you can get the silicone under the joint so when you screw the joints back togeather the silicone will spread forming a waterproof seal that will last forever,well.........longer than me and you will be around anyways.
jimbobly
November 2012
Run a bead of exterior silicone sealant along the joint,it's quite an easy repair.
Rich
September 2011
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