A vented attic where insulation is placed on an air sealed attic floor is one of the most underappreciated building assemblies that we have in the history of building science.
Roof ridge ent something eating plywood.
Shingle obstructed ridge vent warning.
Most roofs will be sheathed in plywood at least 3 8 inch thick.
So much information has been devoted to the subject of roof venting that it s easy to become confused and to lose focus.
Since exhaust and intake must be equal 450 square inches of total intake is required as well.
Be confident about your roof s performance.
If when inspecting from the attic and looking up into the slot of removed plywood at the ridge of the roof you see the under side of a roof shingle either the roofer made the ridge vent a bit longer than needed or something else is going on that we d need to check from outside.
Vents evenly spaced underneath the roof provide intake.
Roll roofing is inexpensive and easy to install.
This gives you 450 square inches of total exhaust.
So i ll start by saying something that might sound controversial but really isn t.
Ways to work on a steeply pitched roof.
The possibility of slipping and falling makes working on any roof dangerous but it s especially so if the roof rises more than 4 feet for every 12 feet of.
As sharptooth said it will delaminate in no time if not covered.
You can use any cheap plywood or even particle board as a short term sheathing on a shed roof but cover it with a layer of rolled roofing.
Something like tar paper over thin plywood hung from straps.
To calculate an example of exhaust and intake use 25 feet of roof ridge vent.
But the idea is that it would evaporate without falling down onto the insulation below.
Loads will vary with the pitch of the roof.
A shallow v trough inside the roof just under the peak ridge to catch any infall.
Multiply it by 18 square inches the net free air per foot of ridge.
Something tells me this would be worse than the original problem 3 use a half ridge vent.
Openings along the sides allow air out of the attic cooling the space and lowering your air conditioning bill.
This option appeals to me.
Block the ridge vent with fiberglass in the winter.
During the evaluation the roofing contractor will not only assess the condition of the ridge vents but he will also identify issues with shingle wear damaged flashing and more.
That will suffice on a roof with rafters set 16 inches apart with minimal roof loads.
Instead of putting the vent square on the ridge open to either side place it only on the downwind side of the roof assuming consistent prevailing winds.
Roofers use a circular saw to cut a long slot along the roof ridge if there isn t one then cover it with a plastic flap as shown or a flexible vinyl matrix.