Insulating a timber frame porch

[moomoojaj]

Thanks for your previous help.
Just one more question. Do I fill the cavity with insulation or do I need to leave an air gap?
Again many thanks

[gasman]

Yes mate. It is quite important to leave a sufficient amount of natural air flow to allow the cavity to breath properly & eliminate damp & fungal growth from occuring. There should be enough advanticious air without the need to incorporate aditional air vents . But if you do include any air vents make sure you use ones with a built in insect screen. You dont want any wasp nests been built in there or other insects making your structure thier new home..
Good luck. ;-)