Sheila -

the "Marine" quality that was put in the MIA spec by the late Vincent Migliori - who
was the MIA technical director until his passing back in 2003 - was one of
Vincent's ways of - shall I say - "OVER engineering" stuff way past where it
needed to be - he was being careful - but in this case, I disagreed with his logic...

Let's put it this way - Let's say you do go to the expense of using marine grade
plywood -
The ONLY benefit you'll have from using Marine grade plywood IMHO - is
IF your kitchen is constantly being flooded - ie - New Orleans from Hurricane
Katrina, and even then - your cabinets will fall apart from the water damage
and your house will be ruined form the mold - but your subtops will
still be good - 'cause they're marine grade plywood... does this make sense???

Vincent was a good friend, but he and I went "round and round" on this point
and although in 25+ years of Fabricating - I have NEVER - EVER used Marine
Grade plywood on ANY project I have ever done in my career.... ACX - Like
we discussed today - will work fine for your application...

IMHO - MIA needs to redact that point in their next Design Manual - I will talk to my friends
there about it - Again - IMHO, 5/8" ACX plywood is fine for a conventional Kitchen application......

Thanks by the way for your very kind remarks - I'm always glad to help
people here on GW!!!!

now - don't bother the US Marine Corps for any more plywood of their plywood!!! HA!!!!

that's a joke there - by the way..... ;-)

Stay with the ACX grade - you'll be fine - 5/8" if you can get it out there
in Virginia.....

kevin

I would agree with Kevin, but will say that I did use a lot of marine grade plywood in my remodel because of it's stregnth and ability to stay stable if water damaged.

We had a garbage disposal go out in the old kitchen. The leak was actually a spray upwards which happened only when using it (until the entire thing fell out). So during the many months it sprayed small amounts of water (which went down into the cabinet, which was slanted back towards the wall so we didn't see water outside of it) it damaged the underlyment (as well as the cabinet eventually). We had horrible corian, so no big loss, but after that damage I decided that the unexpected was possible...and so for a small difference in cost, it was well worth planning for the utmost goofy possible scenario...because we tend to always attract the utmost goofy possible scenario...

If I had been planning on keeping that horrific plastic counter top I'd have had an issue....I did not so it was not a big deal, but I'm glad I also didn't step through the counter while painting...cuz I walk on the counters all the time. (I have quit walking on the onyx counter, but the rest are fair game...and all counters and walls with plywood in them have marine grade in my place).

Its probably overkill, but $30 bucks of overkill is worth it to me!

You might consider checking with a better building supply...they'll have it in stock.