> We're buying a house (upstate NY) where there's been some damage to the
> wood planks near the top of a cathedral ceiling from condensation. [There
[quoted text clipped - 16 lines]
>
> Tony
I do not know anything about Cobra roof vents. I have never heard of that
name, so I can't give you advice about that.
I can tell you that a roof needs venting for a number of reasons, the
condensation you mentioned is one of them. A ridge vent is a good start.
If both the Soffit vents are in good condition and there is good air
circulation between the soffits and the ridge, the ridge vent is all you
need. Check the soffits to make sure there are no nests blocking air
entry, and if you are able to, try to verify that there are no obstructions
between the soffits and the ridge. Check each soffit!
What you are looking for is good air movement throughout the roof cavity.
Having soffit vents and a ridge vent is one way to go. It allows the cool
air to enter at the lowest part of the roof, the soffit. As the air heats
up it rises and flows out the ridge vent.
In the summer time, this will lower the overall temperature of the roof,
helping to keep the house a little cooler, and minimizing heat caused
damage to asphalt shingles, and other roofing material.
In winter, heat that leaks into the roof cavity from the house and doesn't
escape to the outside, can melt snow and ice on the roof. When the melt
runs down the roof and hits a cooler section, it freezes and forms an ice
dam. As more snow and ice melt, the ice dam grows, and forces water into
the roof sheathing, and potentially into the rest of the framing. In
extreme cases, the damage can include water flowing down the walls and
soaking into the floor material.
(This happened to my Mother-in-laws house. A cheap roof fix, instead of a
proper one, resulted in a main door that would not open/close without
excessive force, warped and buckled hardwood flooring, and mushrooms
growing out of the drywall.)
I hope this helps,
Carolyn

Signature
Carolyn Marenger
marson - 26 Dec 2006 00:31 GMT
> > We're buying a house (upstate NY) where there's been some damage to the
> > wood planks near the top of a cathedral ceiling from condensation. [There
[quoted text clipped - 16 lines]
> >
> > Tony
cobra is a commonly used roof vent in our area and it does work well.
you said the soffit vents were questionable....why? I would suggest
adding soffit vents if possible. the last issue that you really can't
do much about without a lot of trouble is providing an air space
between the insulation and the roof sheathing. at any rate, i think
the ridge vent is a good start.
Carolyn Marenger - 26 Dec 2006 09:12 GMT
>> > We're buying a house (upstate NY) where there's been some damage to the
>> > wood planks near the top of a cathedral ceiling from condensation.
[quoted text clipped - 27 lines]
> between the insulation and the roof sheathing. at any rate, i think
> the ridge vent is a good start.
Tony,
Actually, the original poster's building inspector said the soffit vents
were questionable. I said to check them to make sure they allow air flow,
that they are not blocked by nests or other objects.
Yes, the ridge vent is a good start. Good to know that Cobra is a good
vent.
Carolyn

Signature
Carolyn Marenger
Webzine development: www.fivecatsproductions.com
A DIY repair and renovation web magazine: www.ahometobuild.com
> We're buying a house (upstate NY) where there's been some damage to the
> wood planks near the top of a cathedral ceiling from condensation. [There
[quoted text clipped - 16 lines]
>
> Tony
Before you go too much farther into how to vent, check
http://www.buildingscience.com/default.htm
The Building Science Corporation web site is based on research.
TB
Raider Bill - 27 Dec 2006 18:47 GMT
> > We're buying a house (upstate NY) where there's been some damage to the
> > wood planks near the top of a cathedral ceiling from condensation. [There
> > is no attic and the place was uninhabited and without heat for 18 months]
Where in Upstate NY? I was born in Canastota, NY
10 years ago I bought a bunch of proper vents. These are made from egg
carton type foam and are used to ensure airflow past the insulation.
Because I had so many of them I completely did my attic from soffit
vents to the ridge vents. I immediatly saw a major differance even
before I insulated. Temp in my attic dropped on average of 25 degrees
before insulating.
When I built my shop I took it a step further by proper venting the
entire under roof deack then took heavy duty aluminum foil and covered
them. I never needed to insulate after that.
The proper vents I bought wholesale were around .36 each.
Willshak - 28 Dec 2006 05:49 GMT
>
>>
[quoted text clipped - 5 lines]
> Where in Upstate NY? I was born in Canastota, NY
>
Anywhere north or NW of NYC and Westchester Co. is upstate! :-)
> 10 years ago I bought a bunch of proper vents. These are made from egg
> carton type foam and are used to ensure airflow past the insulation.
[quoted text clipped - 8 lines]
>
>

Signature
Bill
in Hamptonburgh, NY
To email, delete the double zeroes after @
Raider Bill - 28 Dec 2006 15:03 GMT
> >>> We're buying a house (upstate NY) where there's been some damage to the
> >>> wood planks near the top of a cathedral ceiling from condensation. [There
[quoted text clipped - 3 lines]
>
> Anywhere north or NW of NYC and Westchester Co. is upstate! :-)
That's a fact. Where I'm from is referred to as central NY. We think of
upstate as Watertown, plattsburgh area and down by the city as the
southren tier
Willshak - 29 Dec 2006 17:23 GMT
>
>>
[quoted text clipped - 16 lines]
> upstate as Watertown, plattsburgh area and down by the city as the
> southren tier
We have to use that designation when we travel outside of the state
because when you say you are from New York, they assume you are from New
York City. :-)
I'm in the Hudson Valley.

Signature
Bill
in Hamptonburgh, NY
To email, delete the double zeroes after @
Raider Bill - 30 Dec 2006 17:02 GMT
> >>>>> We're buying a house (upstate NY) where there's been some damage to the
> >>>>> wood planks near the top of a cathedral ceiling from condensation. [There
[quoted text clipped - 18 lines]
> in Hamptonburgh, NY
> To email, delete the double zeroes after @
Roger that! Same here. I don't want people to think I'm from the 51st
state.
There's no question that adding a ridge vent will be worth the cost (by
keeping the insulation dryer it will actually lower the heating bills) but
the inspector is also questioning the soffit venting. I would trust his
instincts and look closer at improving the soffit venting as well. You may
find that this will consume the better part of your venting dollar.
A good philosophy to follow is, you can never have too much venting in an
attic, and good air flow (not blocked or restricted).
> We're buying a house (upstate NY) where there's been some damage to the
> wood planks near the top of a cathedral ceiling from condensation. [There
[quoted text clipped - 17 lines]
>
> Tony
7h95g - 29 Dec 2006 04:08 GMT
First, thanks so much for all the replies and advice.
The house is inbetween Delhi and Oneonta.
Tony
Raider Bill - 29 Dec 2006 16:03 GMT
I've also been told that if you have ridge and soffit vents then gable
vents are not needed and actually are counter productive.