[Kennedy12]

Has anyone ever vented their microwave oven up through the cabinets to the roof? Any contractor recommendations that do this type of work?

[mulligan]

Depending on how much you cook, you could wind up with some nasty looking grease deposits on the roof. Should be vented through the wall or the soffit.

[fred53]

Never vented a microwave oven...the one here isn't vented either....there's no place to attach a vent to a microwave oven...now if you mean microwave/convection....

[mulligan]

I'm sure the op was referring to the "standard" microwave/range hood here in TV.