I am going to be building in a heavy snow load area.  Snows often pile up to over three feet thick on roofs.

For much of the roof I can have plenty of soffit venting.  Then there is the ridge.  IT seems to me the asphalt covered ridge vents don’t provide much venting, just to thin.  It seems to me this is particularly true once it is covered with feet of snow. 

Would venting be dramatically improved if one were to build venting top cap of their own.  This would be done with say 12′ 2×2 nail one either side of teh ridge parallel with teh rafters and then 18 inch 2×2 on top of them, then shealthing on top.  In orther words, a little roof on top of teh roof.  Some of you in mountian country have probable seem things like this.  This would create a shelttered 1 1/2 inche wide vent, much greater than the factory stuff.  It would also sheild this actual vent from total snow cover (still covered , but wiht much more surface area through which the vented air could percolate.   GOOD?

Secondly, in areas where soffit vents are not possible (ie dead valleys) would such a system with much wider ridge opennings than the factory stuff be even more valuable?