Originally Posted By: kwilliams
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Can you have to much
Just did a home with a Gable roof, ridge vent, The owner put contunious screening on the sofits, any thoughts ??Can you have to much
Just did a home with a Gable roof, ridge vent, The owner put contunious screening on the sofits, any thoughts ??Originally Posted By: rpalac
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My OPINION is that what he did by putting venting along the underside is excellent.
From what I have learned in years of practice and in engineering school (still enrolled) that you can never over do the intake side.
All to often people put in ridge vent systems or power vents, roof turbines, vent caps...etc but never increase or place adequate intake feeds. This creates a negative air problem or a high humidity problem not allowing the heated air to escape.
The other problems not of the same nature but in the same area is how they insulate the heated room under the attic space. All to often they place the craft side the wrong way or place a second craft faced insulation blanket on the existing insulation and create a "false dew point". Very damaging!.....Often you can see this by tiny droplets on the underside of the roof sheathing. This will fail the wood structure in no tike at all.....
All in all...I believe this guy that put all the soffit ventilation in did a very, very good thing..... It will pay off in the summer. The winter time does not have a reverse affect as you would think. The attic should be cold in temp to work properly.
bob
(eager to learn...I'd be curios on other points of view.)
Originally Posted By: dvalley
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Kevin,
As Robert stated, lower intake venting has no limit on oversizing. There are codes that state minimum requirements for attic venting, but too much is better than not enough. Always inspect these soffit/drip edge vents from the top side (attic) to see if these were covered over with insulation. You will find a good amount of these covered over.
I also recall seeing these continuous screened vents in several homes that were painted over by the homeowners. When they painted the eave area, they went right over the screens. All these screens were now blocked by the thick paint. I recommended that these screens get replaced.
--
David Valley
MAB Member
Massachusetts Certified Home Inspections
http://www.masscertified.com
"Some cause happiness wherever they go; others, whenever they go."
Originally Posted By: kwilliams
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Bob and Dave, Thanks, this is what I thought also but have never seen it, Kp
Originally Posted By: phinsperger
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Actualy did the very same thing to my own house when the sofits were redone. Works great. It was the same price to do continous vent or not. Personally I think it looks better also because its all the same and you don’t see an obvious vent every so many feet. Why all new houses don’t do it I do not know.
–
.
Paul Hinsperger
Hinsperger Inspection Services
Chairman - NACHI Awards Committee
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Originally Posted By: jonofrey
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| rpalac wrote: |
|
From what I have learned in years of practice and in engineering school (still enrolled) that you can never over do the intake side. bob (eager to learn...I'd be curios on other points of view.) |
I went to a seminar recently that was hosted by a soffit and ridge vent manufacturer. A couple of points that they made that stick in my mind are:
It is easier to meet NFA specifications using continuos soffit and ridge vents than with any other types of ventilation system.
Gable vents used in conjunction with soffit and ridge vents is not recommended becuase it creates air flow "confusion" (their term, not mine).
It does make some sense to me that gable vents could create a disruption in air flow as intended by the design of soffit and ridge venting systems. I think on a remodel I would consider blocking or removing gable vents if an adequate soffit and ridge system is being installed. On a regular inspection, I wouldn't call it out as an issue, however.
My 2 cents.
--
Inspection Nirvana!
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Originally Posted By: kwilliams
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i agree with the gable vent issue, what about adding a power vent, would it be unproductive with using continuos soffit and ridge vents
Originally Posted By: jonofrey
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Power vents suck.
Pun intended.
Seriously, the consensus is that there are two types of power vents. Those that have failed and those that will.
With an adequate soffit and ridge vent system, there would be no need for any other vents. If the power vent is in place and the roof covering is not being replaced, just leave it there but disconnect the power.
--
Inspection Nirvana!
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Originally Posted By: ekartal
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I either read (or had a dream…) that turbine vents can pull moisture into the attic.
Erol Kartal
ProInspect
Originally Posted By: David Smith
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I have taken a seminar given by a manufaturer of Maximum vents (louvered vents that create an air flow). These vents are now being used instead of turbines as they have no moving parts and create the same type of air flow. Two points that where mentioned-
-when their product is installed it is recommended to close the gable vents to provide the proper air flow from the lower soffit to the upper vent.
-if there is inadiquate intake venting, turbine or the louvered type vents can pull moist air from inside the house if it is not well sealed, which could then condense in the attic.
http://www.ventilation-maximum.com/eng/indexen.htm
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David Smith
Professional Building Inspections
Originally Posted By: Gino Conner
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| jonofrey wrote: |
| Gable vents used in conjunction with soffit and ridge vents is not recommended because it creates air flow "confusion" (their term, not mine). |
The way it was explained to me made perfect sense. If you put gable vents in a soffit/ridge vent system, the air will flow in through the gable vents and out through the ridge vent, effectively bypassing the soffit vents all together. The only portion of the roof that will be receiving a fresh flow of air is the upper most portion.
Originally Posted By: Mike Parks
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I used a cont. ridge vent. My entire soffit is vented. I also vented the gable ends( the ladders if you will ), to help the roof not to rid moisture.
I will have snow on my roof weeks after everyone elses melts.
Mike P.
Originally Posted By: jonofrey
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| Mike Parks wrote: |
| I used a cont. ridge vent. My entire soffit is vented. I also vented the gable ends( the ladders if you will ), to help the roof not to rid moisture.
I will have snow on my roof weeks after everyone elses melts. Mike P. |
and this is good because.........
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Inspection Nirvana!
We're NACHI. Get over it.
Originally Posted By: Blaine Wiley
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I’ll take a stab.
Because you want your attic to be the substantially the same temperature and humidity as the outside air so as not to condense moisture. Snow on the roof indicates that.
Originally Posted By: roconnor
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Also consider the increased possibility of Ice Dams if you have inadequate ventilation that will not keep the temperature constant, although ceiling/wall insulation is the best thing to prevent that.
http://www.extension.umn.edu/distribution/housingandclothing/DK1068.html
--
Robert O'Connor, PE
Eagle Engineering ?
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NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: dhartke
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Mike and Blaine,
I'm with you. When it warms some and the snow begins to melt I like to see a gradual and even melt on a roof. I may be wrong but I think that's an indication of a good balance of ventilation and insulation. When I see ghosting of rafters or isolated melt areas I'm thinking condensation might accompany. I certainly welcome an expert to cut and paste here.
Dave
Originally Posted By: Rusty Rothrock
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To my way of thinking (having been a custom home builder for 12 years and a home inspector for 7 years), the perfect attic ventilation scenario is the following :
Continuous soffit vent, continuous ridge vent, R-40 to 48 attic insulation, gable exhaust vents with one electric gable exhaust fan (thermostat controlled).
Here in Virginia, the continuous ridge vents just don’t allow enough heat to get out of the attic in a quick enough fashion. Even with soffit and ridge vents, attic temps can still get in the 120-130 range. I have found that an inexpensive ($80-$100) powered gable exhaust vent (thermostatically controlled) at one end of the attic makes a world of difference. I normally suggest to set the thermostat at 110.
The goal is to have your attic temps to be the same as the exterior, year round.
Best Regards,
Rusty Rothrock
Richmond, VA
Originally Posted By: dvalley
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At 3.25 per inch this will require approx. 11 or 12" of blanket thickness in order to get the required value of R-36/38.
Now I'm off topic, Sorry.
--
David Valley
MAB Member
Massachusetts Certified Home Inspections
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"Some cause happiness wherever they go; others, whenever they go."
Originally Posted By: Rusty Rothrock
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David -
I use to design and build passive solar houses so I'm always putting in more insulation that what "normal" people would do. There is absolutely nothing more cost effective to improve one's house (and to save a ton of money in fuel bills) than to install more insulation in the attic.
The thickness of insulation and the reciprocal U-factors (heat loss) have a direct relationship. If you have 3" of insulation and you add another 3", you have just decreased your heat loss by 50%.
In the solar houses I use to build, we used a double studded 9" exterior walls that was R-40 and then did R-48 in the attic. I'm just real big on insulation because I'm always looking to save money on energy costs.
In fact, I'm presently building a 1,000 sq. ft. Master BR addition on to my house (with 2 1/2 car garage below) and I'm using a very unique window. Believe it or not, it's an R-10 double hung window (triple glazed with Krypton gas, low E, the whole nine yards). It's made in PA by Gorrel Industries. This window is 5 times more energy efficient than the normal R-2 double pane insulated window.
Have a great weekend.
Best Regards,
Rusty Rothrock
Richmond, VA