Will Luan fall apart in the rain?

I am closing in on being finished with my Benroy. Seems like it's been a long 4-5 months.
I'm posting a few pics as I'm proud of the work I've done. This is the first time I've built anything pretty much!
Anyways a carpenter friend of mine said that the Luan roof on my camper will fall apart in the first rain or even a heavy dew!
Is that right? What do I need to do to protect the top?
I'm posting a few pics as I'm proud of the work I've done. This is the first time I've built anything pretty much!
Anyways a carpenter friend of mine said that the Luan roof on my camper will fall apart in the first rain or even a heavy dew!
Is that right? What do I need to do to protect the top?