My house has an exterior door on the South side for a small closet that holds our gas water heater. The door is 24" by 48". My house is in Los Angeles so there is lots of sun, some rain and no snow.
When we looked at the house before we bought it, there was a plywood door that was falling apart. The termite people replaced the plywood door with a hollow core door.
The hollow core door soon started coming apart because of the rain getting it wet. I looked at Home Depot but did not find a door that size so I glued it back together with a construction adhesive in a caulking tube that was supposed to be waterproof.
The door is coming apart again so I want to make a new door out of exterior grade or marine grade plywood and coat it with several coats of spar varnish, marine grade epoxy or some other finish. I want something that will last at least 20 years.
Marine grade plywood is quite a bit more expensive than exterior grade. Would it be worth the extra cost in this application?
What would be the most cost effective finish for this application (assuming my time to be worth $10 per hour)? Thank you in advance for all replies.
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