Oops ....where is the starter?

Our tendency to err is also what makes us smart. Here's what we'd gain from embracing it in this scenario. Dealing with low profile mesh or plastic ridge vents do not pass as much I will repeat do not pass as much air as the older ( uglier) higher profiled aluminum vents. Sure, the plastic or mesh shingle over look good. The question, is it venting properly? I would suggest that the uglier aluminum exit vent along with making sure that the roof decking slot is cut correctly on both sides of ridge board is the best In general, you want 2x as much intake venting as outlet.If you use a mesh type the ridge opening is obstructed by the mesh so you can't just measure the sq.in. of vent opening, Adjust your calculation for the vent opening obstructed by mesh, screening, under-sized cuts into the roof deck. B) :) :) B) Deep Down In Florida Where The Sun Shines Damn Near Every Day

CIAK & Raven: You are saying that only the far end ridge vent, the highest one should've been vented?????? :blink:

I believe that you guys are talking about the lower, perpendicualr ridge, unless you are truly blinded by science. That is separated from the others.

You are correct that is necessary. You also jump to a lot of conclusions....... :dry:

A really good conclusion I've drawn is that everyone is adding ridge vent, very lttle soffit vent, no baffles and absolutely no attic separation. And the customers rarely don't care and of course the inspectors/ building departments are clueless (and just collecting the permit tax).

A healthy attic is a healthy home ;) or at the least a healthy roof system :)

Also as I've learned from my m'fer. it is if the difference between the high/ low ridge is under 3 ft., then the areas don't have to be separated. Tell me more... :)

EGG: Ventilation is an imperfect science at best. I've seen plenty of systems that work that aren't supposed to.

On a church job that I lost this summer, I was beaten down with calls of "RIDGE VENT"!!!!! I said "why? You have very little insulation in the attic, the Sanctuary is bleeding heat into the vented attic thru the uninsulated wall and you have no separation from the lower area vented area to upper vented area. It is all mixed up."

Need less to say I did not give them what they wanted and lost the job. But they did get lots of ridge vent w/ inadequate insulation....and questionable intake :blink:

Excess ridge vent will cause air movement between ridge vents, but being excess doesn't always inhibit eave flow. There's too many variations in house design to be able to make all-encompassing statements either way.

I don't buy that air flowing in from the soffits is drier than air flowing in from the ridge, the air humidity level doesn't change. Sure, blowing rain would be wetter, but that would be a leak issue and not a ventilation issue.

I'm seconding Raven on the Lomanco. Hands down my vent of choice. I'm seconding Tom on the vent going all the way, even though my cuts stop before reaching overhangs, etc. I guess nobody reporting here so far saw Dennis Crookshank's video that he made which casts some legitimate doubt on the sanctity of the top/bottom perfectly balanced act with no other vents allowed. We will all be learning more as time passes. I guarantee that.

You guys are right. I am going to quit doing attic inspections and just listen to some guys on the internet :laugh:

Ravens got it right. For all you ridge vent junkies who follow practises similar to those posted by Twill. Shame on you. Bad practices Adding lower level ridge vents and or gable end vents where a continuous ridge and soffit vent system is installed will prevent proper roof ventilation so long as you have un-blocked soffit intakes and ridge outlet openings. When warm air in the attic moves upwards by natural convection and exits at the ridge, cooler drier air is drawn into the attic or under-roof space at the building eaves or soffits. That incoming air to treat the entire under-roof surface, from the lower edges or eaves up to the ridge, by flowing along the underside of the roof deck and out at the ridge. If you were to add gable end vents different level ridge vent, some of the draft created by air exiting at the ridge will be satisfied by incoming air at the gable ends, or lower level ridge vents. The lower level ridge vents or gable vents are naturally closer to the ridge than are the soffit intake vents. As a result, less air flow will be provided for the lower center portions of the roof, and the benefit of cooling and drying the entire roof underside surface will be impeded if not blocked. B) ;) :( B) Deep Down In Florida Where The Sun Shines Damn Near Every Day

In my opinion Lomanco makes the best on ridge vent. It has internal baffles without the fiberglass mesh that restricts air flow. Take a look at their FAQ's. It is very educational. For example the above pictures....The ridge vents are not supposed to be on different levels unless each level is closed of from the other in the attic. The top vent will use the lower vent as an intake. Which will bring moisture into the attic. Also the intake and output should be equal. If one is more than the other it should always be intake.

kage Said:

Alba Said: Somebody was telling me the other day that he ran a smoke test on a 5:12 with a ridge vent on it.He claimed that he barely saw any smoke coming out of the vent .

Was there any soffits or were they plugged?

Alba Said: Somebody was telling me the other day that he ran a smoke test on a 5:12 with a ridge vent on it.He claimed that he barely saw any smoke coming out of the vent .

Alba,why would you say that? we put miles of ridge vent on in Miami after Andrew,like was mentioned,with adequate soffit vent it's gonna flow." Somebody was telling me the other day that he ran a smoke test on a 5:12 with a ridge vent on it.He claimed that he barely saw any smoke coming out of the vent .

Yes we run it to the end. Simplifies the install and looks better in my opinion

Old School Said: As long as there is adequate soffit vent, nope!

Ridge vent may not help much on this kind of slope.

As long as there is adequate soffit vent, nope!

Is there a point when there is too much ridge vent?