Why a 1/4" gap at the bottom of the hatch?

[kayakrguy]

Folks,

I realize there is a need for a 1/4 inch gap at the top of the hatch for the hinge to be able to swing without binding.

What is the purpose of the gap at the bottom that some people put in?
I'ms not clear about that.

Thanks,

Jim

[halfdome, Danny]

Weatherstripping

[Steve Frederick]

Weatherstripping

Yeah! Use a seal that is a bit thicker than that gap, say 3/8", so that it compresses when the hatch is closed. Try to get closed cell foam, or rubber, it resists water penetration. Open cell foam will leak!

[madjack]

yeah...what they said...many folks have made the mistake of fitting hatches and doors tightly, leaving insufficient room for the seal and having to recut to make it fit or putting up with a bulge to get it to close...most seals are made to work best at around 50% compression...IE, 1/8"th gap for a 1/4" seal, etc. etc. etc.
madjack