C & E wrote:
"JD" wrote in message
...
I'm in the process of getting a new roof and the first roofer wants to
install ridge vents, which I wasn't familiar with. I've done some research
and ridge vents seem to be a good idea? I have some questions:

I have a hip roof so do the ridge vents go on every ridge or just the top
or highest ridge?

I found a web page that talks about the relationship between the amount of
ridge vent and number of soffit vents.

http://www.rd.com/familyhandyman/content/18231/0

If you scroll about half way down the page they talk about Minimum Venting
Requirements. Is the information they provide correct? It says a 1,500 sq
ft attic will need 10 sq ft of venting, half on the roof and half on the
soffits. They say the factor is 1 sq ft of venting for each 150 sq ft of
attic. Is that correct?

--
JD..

You will have to see if the roofer is willing to install the soffit vents
and factor that into the equation. I would do my own math, however. I had
about half of the required vents installed nearly 15 yrs ago and the time
has passed quickly meaning, I didn't add the difference. Now it's time for
new soffit and fascia so we'll be using perforated soffit this time. I
don't believe I can over-ventilate.


I already have soffit vents. My question is do the ridge vents work as
well as the little square vents every so many feet and on a hip roof are
the ridge vents on every ridge. I have I have six ridges. I'll talk to
the roofer in a day or two to see how many ridge vents he planned to
install and then as you say do the math to see how many soffit vents are
needed to take advantage of the ridge vents. From that web page I
posted, you need as much net free vent area in soffit vent and ridge
vent to ventilate properly?

--
JD..