Do I really need to make my own vent shoots for my roof?
It is typical around here for the insulation contractor to install cardboard(cheap) vent baffles as part of their work. It was not until I started reading here that I would ever consider it needed to be done different. I have never heard of a vented roof failure around here(Zone 4C, but on the dry side).
Installing site built vent channels with 2×2 and OSB is an obvious better choice than cardboard. But it is more time, energy and cost to an already costly and time consuming project.
So the question is: what am I truly gaining here? Is it peace of mind knowing the roof is ventilating more effectively? Or is it from an energy standpoint of less air washing over and through the insulation(assuming I air seal the vent shoots.) Perhaps both.
In your opinion, is this a step I should definitely take the time to do? As opposed to letting the insulation guys do it how they do every other house?
thanks
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Replies
Joe,
Baffles are used in two situations. To create a continuous vented cavity in cathedral ceilings, and to keep the insulation on the bottom chord of attics from blocking the ventilation path into the large open space.
For the latter the shape and composition isn't as important. For cathedral ceilings however you want a baffle the is both air-tight and extends over the whole surface of the rafter bay. If you can find a manufactured one that does that, there is no need to site-build them.