Attic Ventilation Expert Needed - North NJ Area

[jeff]

(Sorry about the last blank post, which was an accident.) Anyway, my problem is there is mold growing in my attic, primarily on the ceiling, underneath the roof sheathing, and mostly on the side of the attic in which the roof is facing the north. I'm looking into getting the mold cleaned up, but it seems to me I need to have the ventilation issue taken care of first. A roofer looked at my roof, and doesn't think there are any active leaks. My roof is less than 9 years old.

My attic is a crawl space that is around 1000 square feet in size, and I'm guessing that it's maybe about 4 feet high at the center. There are two gable vents; one on the east side and one on the west side. There are two passive square vents near the ridge of the roof. There is almost no ventilation at the soffits, that is, my attic does not have soffit vents, and, although there are a couple of little places where I can see daylight near the eaves, this doesn't amount to much.

A roofer is talking about installing another roof vent with a temperature controlled fan near the center of the roof near the ridge. I'm just wondering if doing so would be helpful, or would it turn out to be no help, or problematic? My fear is that the fan might just draw air inward from the two closest vents, which are the existing square passive roof vents. Am I incorrect in suspecting this could happen?

My understanding, is that the consensus on the internet is that the state of the art in attic ventilation is to have continuous soffit vents with a continuous ridge vents. Since my attic currently already has two gable vents, plus two square passive roof vents. I'm just wondering if switching to the ridge/soffit system would be the only real solution to my attic mold problem, or if there would be a way to improve upon my existing ventilation system (such as a installing fan). Any ideas. Basically I need to ensure that whatever I have done ventilation-wise is going to be a real improvement which results in mitigating the chances of mold growth. Any recommendations?

Thanks.

Jeff

[Speedy Jim]

Gable vents and roof vent send the air where it's *not* needed; the air bypasses the problem areas-the roof sheathing between rafters.

Jim

[jeff]

Hi Jim,

Thanks for the reply. Yes, I'm already aware that a continuous ridge/soffit system is considered to be the state of the art. However, since my attic already has two square passive vents near the ridge, I'm wondering if there might be another satisfactory, yet cost effective, solution to my attic mold problem than simply closing off all 4 of my existing vents and altogether switching to a continuous ridge/soffit system.

My attic is 1000 square feet of crawl space. Suppose I were to have a roofer add, say 2 or 3 additional square passive vents near the ridge. My roof would then have a serious of, say, 4 or 5 square passive vents near the ridge rather than having only 2 square vents near the ridge. Now suppose I also had the roofer add soffit vents, and I were to close off the two existing gable vents. Would having soffit vents plus a series of square passive vents near the ridge function almost as well as a continuous ridge/soffit system, or do you think my only valid option is to have a contuous ridge vent installed?

Is there a way temperature or humidity-controlled fan-power vent could be utilized to enhance my existing system, or should I stay away from a fan-powered vent altogether.

Again, is my only valid option to have a contuous ridge/soffit system installed or are there any other satisfactory yet cost effective solutions (such as a series of passive square roof vents near the ridge combines with soffit vents)? My attic is roughly 35 feet long by 28.5 feet wide. If a series of square passive roof vents near the ridge would work well in conjunction with soffit vents, then how many 9" vents would you recommend I get installed?

Thank you, or anyone else for your advice. Just out of curiousity, is there anyone out there who disagrees with the idea that my gable vents must be closed off altogether in favor of a ridge/soffit system?

Jeff

[HA HA Budys Here]

How the moist air escapes isn't an issue here as long as there are sufficient means for that to occur. Your problem is how to introduce fresh air where it's needed, which is down near the soffit areas. A continuious soffit vent is ideal, but those 2" round discs work well too.

A powered gable vent does nothing but suck air in from the ridge if both types of vents coexist.

[jeff]

Well, the roofer is talking about adding a powered vent near the ridge, not at a gable end. However, since there are already two passive roof vents near the ridge, my fear is that the fan would likely cause the two passive roof vents to suck air in and short circuit the benefit of the fan.

I'm thinking about having soft vents installed plus additional passive roof vents near the ridge, and perhaps closing off the gable vents. Would a series of passive vents near the ridge work well in conjunction with soft vents? While I'm told a continuous ridge vent in conjunction with soft vents is the state of the art, since there are already two passive square vents near the ridge, I'm wondering if simply adding more passive square vents would be a sufficient yet cost effective improvement, as long as I also add soft vents. If I do this, then is closing off the gable vents a must? What do you think?

Thanks.

Jeff

[Oscar_Lives]

Just add more vents and don't close any of the existing ones. You need MORE ventilation and any more you can add will help.

Make sure you have enough soffit vents.

Adding a power vent with other roof vents and/or a ridge vent would still be helpful. That is a bunch of BS that it would be ineffective because it would "short-circuit" the air. You need more ventilation. Any ventilation would be good. Any.

[Speedy Jim]

jeff wrote: Would a

I'm in agreement with you. Do sufficient soffit vents along with passive roof vents, but block off the gables, they will not create air flow

[Speedy Jim]

[Sorry, hit SEND too soon.]

Jim