Hip, Ridge and Soffit Ventilation
Summary: Ridge vents and soffit vents are a necessity to keep roof rot problems out of new homes. Houses release moisture into attics. Ridge attic vents remove wet air quickly.
DEAR TIM: The buzz word in my area about new roof and re-roofing jobs is ridge and soffit ventilation. I don't remember seeing any of these products on the houses I grew up in. Are they really necessary? What happens if your house has a hip roof? A friend of mine who lives in the snow belt had one foot of snow accumulate in his attic because of these devices! I wonder if this ventilation trend is just a clever trick to sell something that is more trouble than it is worth. Charles P., Wahoo, NE
DEAR CHARLES: These new hip, ridge and soffit ventilation products are indeed clever. But don't think for a minute that they are a tricky gimmick sold by a motivated roofing salesperson or a builder. These products are innovative and an absolute necessity. New houses built without ridge and soffit ventilation can have serious roof rot problems. I know it for a fact as it happened at my own home.
There are several good reasons why older homes did not have nor were required to have ridge and soffit ventilation. Older homes often had windows and doors that had no or poor quality weatherstripping. Air infiltration barriers had yet to be invented. The massive amounts of cold dry outdoor air would mix with the warm moisture laden inside air. The net result was that the indoor humidity in older drafty homes was far lower than indoor air you might encounter in your existing home. To make matters worse, as older homes are improved with new windows, doors and other energy saving suggestions they become condensation time bombs.
Since the wall systems of new homes and improved houses no longer leak air, the houses release the moisture into the attic spaces. If this moisture laden air is not quickly released from a cold attic the water vapor can condense on the cold wood surfaces in these spaces. If this happens wood rot will indeed happen as it did on my own house. Soffit, ridge and hip ventilation products allow Mother Nature to vacuum this moisture laden air from your attic with each puff of wind that blows across your roof.
As with most building products necessity is the mother of invention. Your friend that had snow in his attic probably had a low quality first generation ridge vent. Many of these allowed blowing snow and sometimes rain to enter attic spaces. New ventilation products are now available that will block snow and rain from entering attics. In fact, special hip vents can now be purchased that satisfy my tough demands. Hip vents are special because they need to have internal baffles that block snow and rain that can blow sideways across a roof. If you have a hip roof, be sure you install a special vent on these areas of your house.
The ridge and hip vents come in all flavors. You can purchase different colored metal vents that act as the cap shingles at the top of the roof. Other vent products are coils of plastic fabric that resembles coarse steel wool. My personal favorite is the hard plastic ridge and hip vents that are strong enough to stand on. These are applied over saw cut openings at the top of the roof or along a hip ridge. You then nail the roof shingles over the vents. Only a trained eye can detect their presence from the ground.
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Comments:
DwightB 13 Apr 2008, 22:09
Can you name a preferred product? We seen some of those first generation
products used unsuccessfully and have tried 2 or 3 different brands, some
with success, some failing, especially in a severe ice storm, water had
piled on the roof behind a massive build up of ice and poured right into
the slot. Adequate ventilation of a hex or octagon roof remains a problem.
danny 24 Jun 2008, 08:31
sir,
i am having my roof redone. i have a hip style roof. my roofer wants to put both a ridge vent and air hawks on the roof. i am worried since i hear air hawks cancel out ridge vents. my hip roof is such that i dont have enough room for adequate ridge venting. so i need something additional. do you recommend hip vents? should i get a ridge vent with the hip vents or just the hip vents?
Mark Weller 22 Nov 2008, 13:07
I live in a condo. My attic area of the condo is on the hip side of a hip
roof. We have added R-49 insulation which is great. The condo building has
a combination soffit-ridge vent. However, my ridge is very small or short.
A fire wall prevents full air circulation in the "larger" part of the
buidling. In addition to the short ridge vent area, can other roof vents be
added that will enhance air flow?
Randy 13 Dec 2008, 16:17
We recently constructed a house with louvered/screened soffit vents (not
continuous) and a "mesh" style continuous ridge vent. We live in Wyoming
where fine snow blows at 40+ mph on a regular basis. I noticed that very
fine snow blows into the soffits, up the insulation baffles and into the
attic. Does anyone know how to stop this besides covering all of the
soffits every time the wind blows? Are there any soffit vents that work
better? Even the ridge vent allows a tiny amount of fine snow in.
Thanks!
Rick H. 12 Jan 2009, 22:21
We live in a split foyer in South Dakota which was built in 2001. The
builders used a ridge vent over the main section of the house. Due to the
amount of wind we have in SD, we've had to deal with snow getting into our
attic through the ridge vent and it's been enough that I've had climb into
the attic and remove it. The ridge vent is the plastic/rubber style where
the hip shingles are fastened through it but it isn't doing the job. Can
you list the name of a more dependable ridge vent? Please reply at your
earliest convenience.
Thank you, Rick H.
Betsy Dawkins 11 Mar 2009, 07:24
I have heard a lot of problems about snow blowing in the attic and i have
not heard any answers to the problem. i have a 1900 home with only a vent
in the wall of the attic. It is even leaking thru the ceiling. i have put a
sheet of plastic to allow the snow to evaporate. what can be done?
Daniel 27 Mar 2009, 15:43
Look into Ventilation Maximum. A company from Canada. They have several
products which may help.
Ron Frank 18 Apr 2009, 13:06
I have 1,700 SF of attic space. Should I install two 1200cfm power vents
on my roof, or would ridge vents be best? Each end of my roof is hip style.
Larry Dunn 09 Jun 2009, 11:54
I have a hip roof and need to determine which kind and numbers of vents I
should have. I live in Florida, so the issue is driving rain as well as
ventilation.
Clayton Chaney 29 Jun 2009, 14:21
I am designing a hip roof house with both trussed and cathedral ceilings
throughout. What is the extent of hip and ridge vents required? Do i need
to worry about a balance level intake and outake air openings? Is air
pressure balance a big concern? I've read things that make it seem like
its a big issue and really makes venting hip roofs tough. I'm looking for
a solution that doesn't compremise the "clean" look of my roof form.
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