Are there roof ventilation specialists?


#1

(Figured I should start a new thread for this one…)

I’m going to try to find a contractor who has experience with solving ventilation problems on a 7 month old roof (moisture/condensation/mold), and sizing/installing vents into old soffits. (my house is 1923)

As has been well-advised in my other thread, I should get a person who can do it right the first time, otherwise I’m in for big problems in my attic/roof.

I was wondering if there are “roof ventilation specialists”? Or if not, am I more likely to find a “roofer” who is experienced in this, or a “ventilation” guy, or a “carpenter”?

TIA & HNY!

-Rich

p.s. I also have to add an exhaust fan/duct for my upstairs bathroom and was wondering if it was likely or unlikely that the same contractor could do both. (as you can tell I haven’t been down these roads before)


#2

Give us some information about your roof…pitch, shingles, underlayment, amount of moisture drive (high/low)


#3

Hi,

Your bathroom fan can be exhusted straight up an out the roof. This way the mostiure is vented above the shingles.

In stead of running sideways. where they exhust the mosture in to the soffit area. This allows the mosture to be drawn back into the structure.


#4

There are few contractors that feel ventilation is the most important thing on the roof. Good luck finding one they are hard to find. Most companies throw shingles on the roof and concider it done. Kinda like the guy who put ridgevent on your home without soffit vents. Those are also the guys who for some reason cheat on there insurance and do not have the proper insurances by using GC style insurance rather than roofing insurance. I have outlined in my previous post what you need to do to solve your problem. If you have a bathroom vent by all means have it exhaust out of the roof. The straighter the piping for the vent the better. Laying it down in a flat state can lead to moisture build-up and possibly mold. I would have it exhaust thru the roof with a pipe that is as straight as you can make it for these reasons. Good luck in your quest.


#5

So do I take it that the answer to my main question (the subject) is “no”? There isn’t really a field of contractors who specialize in roofing ventilation?

My contractor, who I spoke with today, said he has a carpenter referral for the soffits but I asked him if he knew of anyone who’s really been down this path before (e.g. new roof leads to moisture, condensation, mold) and he said he didn’t know anyone but would ask around.

He’s still a decent guy, even though he apparently didn’t understand the importance of a soffit+ridge ventilation system for my house. He called me back on New Year’s Day… there aren’t too many contractors I’ve encountered who would do that.

Still I’d really like to find someone who’s been around the block with my kind of problem once or twice. Any advice on how to find such a person?

I’m really focusing this post on the soffit venting issue. I feel like the bathroom venting/ducting is more straightforward, although perhaps I have a lot to learn about that also. :wink:


#6

no there isnt a ventaliation specialist field that i know of. most ventaltion experts are roofers(however only some of us understand or care to understand about ventilation) look in the local yellow pages for a roofer whos ad mentions ventilation. maybe look for a product logo such as “airvent” on their ad. and check refernces.


#7

It’s kinda bizarre. It seems that with the modern code for roofing, that new roofs tend to be quite air tight. (clearly my new one is way more than my old one) And the soffit (intake) + ridge (exhaust) concept is pretty simple to understand. So why do so many roofers just put in ridge vents without soffit vents?!

All I can figure is that soffit work is more finish carpentry so it’s not the usual skillset for a roofer. Even so, that’s lame, but I’m sure that’s something you guys talk about a lot on this forum.


#8

Anyway, back to soffits… If there aren’t roof ventilation specialists per se, then I guess I’m going to end up getting a general carpenter to do soffit vents. And if so, I have these questions…

Q1: Is installing them usually straightforward, e.g. the 4x16 variety?

My attic footprint is 24’x32’ (ridge=32’). And it’s 8.5’ high from attic floor to peak. It’s an open (cold) attic, with exposed rafters, no insulation in the roof… only the floor is insulated. And the insulation stops just before it reaches the roof at the edges/eaves so that there is at least 2" of channel there for air flow.

I have 19 rafters about 22" on center, so 18 bays. I was told the correct number of 4x16 vents was 10.

Q2: Does that sound right? And would that be 10 total or 10 per side?

Q3: So apparently it’s OK to have one 4x16 vent per every 2-3 bays, true?

Q4: I’ve never seen how (my) soffits are constructed, but I’m wondering if they might be subdivided internally into several cells (for lack of a better word) meaning that it’s not one big long continuous cavity. If so would you have to know where those divisions are and plan your vent locations accordingly?

Q5: Should I expect to be involved in calculating the number of vents so that the soffit/ridge balance is right?

Q6: I’d probably be willing to pay a little more to err on the side of oversizing the soffit vents slightly. Would that be a bad idea? Being slightly out of balance, more intake than exhaust? That couldn’t worsen the air movement underneath the roof, could it?

THANKS, THANKS, THANKS AGAIN for all your advice! I’m always appreciative of forums like these when I have to come up to speed quickly on something.

-Rich


#9

Oh, and just to make it an even seven :wink:

Q7: Any challenges to installing soffit vents in January in CT, other than possible snow on the ground? e.g. Caulking isn’t typically required?


#10

Hi rpr.

The others on here would like you to belive that all the other contractors are ignorant. You yourself are buying into this.

The reason that a contractor will install just ridge vent is it will exhust hot air. Contrary to what you were told. Another reason is the customer will not pay for intake to be installed.

We will do this. You just sign a paper stating that we did offer you the intake.

Most house’s will do fine without the additional intake.

Yours did not.


#11

[quote=“Lefty”]The others on here would like you to belive that all the other contractors are ignorant. You yourself are buying into this.

The reason that a contractor will install just ridge vent is it will exhust hot air. Contrary to what you were told. Another reason is the customer will not pay for intake to be installed.[/quote]

Actually I don’t buy into the idea that other contractors or most contractors are ignorant. But I do now buy into the idea that soffit+ridge vents is better than ridge-vent alone, especially on new tight roofs.

And yes, I did consider the budget theory of why they get left out. I’m a good example of that… I didn’t want to pay for soffit vents if I didn’t have to. However if my contractor had insisted I would’ve done them.

My contractor I still like. He says he does ridge-vent-only installs a lot and he’s only had 1 or 2 condensation problems like mine. I believe him. But it’s clear from talking with him that he doesn’t fully understand the “science” of moisture/condensation/ventilation with regards to my attic (I won’t go into the details) and that has put me in this predicament.

Anyway, more importanly I still hope I can get some feedback/answers to those questions I posed just above about soffit vents.

Thanks.

-Rich


#12

[quote=“rpr”](Figured I should start a new thread for this one…)

I’m going to try to find a contractor who has experience with solving ventilation problems on a 7 month old roof (moisture/condensation/mold), and sizing/installing vents into old soffits. (my house is 1923)

As has been well-advised in my other thread, I should get a person who can do it right the first time, otherwise I’m in for big problems in my attic/roof.

I was wondering if there are “roof ventilation specialists”? Or if not, am I more likely to find a “roofer” who is experienced in this, or a “ventilation” guy, or a “carpenter”?

TIA & HNY!

-Rich

p.s. I also have to add an exhaust fan/duct for my upstairs bathroom and was wondering if it was likely or unlikely that the same contractor could do both. (as you can tell I haven’t been down these roads before)[/quote]

Hello Rich ,

Have you tried gable vents . . . Unless your roof is hipped , this can help your problem considerably . I believe in conn. they are still installing gable exhaust vents with thermostats . . . perhaps look in to that . Hope that helps .


#13

I left you a private message. Email me your phone number.


#14

OK, I’ve had a couple of carpenter/contractors over to look at my house for adding soffit vents. The choices being discussed are continuous (std 2" variety) along entire soffit length and 3" round mini louvers in each rafter bay. So, questions about that:

  1. Continuous looks like it provides much better flow, and across the width of each bay, as compared to the round louvers which are more like a point source. Continuous seems superior so I’m leaning that way, but it might be 3X more $. Do people think continuous is generally worth it? Or specifically in the case of my moisture/condensation/mold problem?

  2. Louvers seems to come with built-in screening to keep bugs out, but the continuous I’ve seen does not. Are there any continuous products with screening? (I’ve had some bugs up getting up there before and I don’t want to give them an open invitation!)

  3. I know that there’s supposed to be a balance between air flow of soffit intake & ridge outlet. I imagine that with continuous I’ll end up close to balanced but if it turns out that soffit’s provide much more air flow than ridge is that a bad thing, other than having spent more $ on my soffit vents than I had to?

Thanks as always.

-Rich


#15

if it were my house i would go with the continuos vents. the 3" rounds tend to fall out, and have FAR lass airflow.


#16

Thanks Marshall. Any ideas about the other questions, especially the screening?


#17

well…hmm…maybe you can put screen into the continous vent as its being installed.


#18

So I’m getting the impression that there may be no such animal: continuous soffit venting with slots and screening also built-in.

No-one has heard of such a thing?

I wonder why… screens inhibit air flow or get dirty/clogged more easily?


#19

im not saying there is or isnt…to be honest i never looked at it that close to see if there was. i would look at some of the product specs from the manufactures. check out www.airvent.com


#20

I did that earlier. Spoke w/ Airvent and they said they don’t make continuous with screen. She thought it was an air-flow issue primarily.

The only thing she could offer was their alternative “perforated” style, which has a bunch of 1/8" dia holes.

Anyone ever used the perforated one? I wonder if they look good as the normal louver-slot style? And if they would keep bugs out any better or worse?