probably a unique question!

andaman

hi to everyone,

i am building (or attempting to guide) the building of a resort in the andaman sea on the thailand coast. problems are many as are the choices. i am not a builder or skilled in DIY. (feel free to abuse me etc 'what the hell are you doing' etc.....)

anyway back to the subject. i have built three houses on a sandy/soil peninsular ...the architect assures me the foundations will be solid :-)

they are breeze block two floor construction 45 sq metre floor area.

this is my question. i want to keep the roof light and strong. i have the idea to use green board over the metal roof skeleton over this the local grass 'sheaves'. this grass sheaving is quite hard wearing (ive used it on 7 units of a lesser quality already)
thermal properties are what im interested in
1. does green board 'breathe?
2. what are the water/rain protection properties like?
3if a metal roof skeleton is going to expand with heat (frequently 40 degrees centigrade here ....120 F ... will the greenboard crack?
4. anyone ever done this before?

if i use tile (here in thailand its a thick heavy cement tile with a wave called CPack...... im sure the weight plus heat retention will make the house an oven!

i am on an island, my builder is a local there is no one here with a knowledge of materials etc ....its all pretty basic ... so easy and simple are the key elements to good choices

thanks in advance to anyone who has the time to reply :-)

andaman

Windows on Wash

Make sure you get a vapor barrier under the foundation.

By green board, do you mean a zip wall sheathing?

I am not sure what the perm rating on the Zip panel is but it is probably near what OSB is at around 5. You should not have a vapor barrier in your climate if I were going to hazard a guess.

OSB is temperature stable to pretty high temps so you should be more than fine.

Go with a high solar reflectivity metal.

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