Abstract: A weather tight fastener, for joining two or more adjacent members, having a flanged sleeve member which is disposed through aligned openings in the members and a rod member having an enlarged end, engaging a portion of the tubular member for collapsing the unflanged end of the tubular member in a controlled fashion. The end of the rod member which is not enlarged, projects from the flanged end of the tubular member and is engaged by a holding plate which is slidable in one direction only. Disposed between the slidable holding plate and the exposed surface of the members to be joined are a rigid washer and a resilient washer which are necessary for proper setting and providing a secure weather tight seal. The rigid washer has a counterbore of the same general size as the flanged end of the sleeve. The steel washer is disposed with the flanged end of the sleeve nested in the counterbore.