View Full Version : ridge vents and hurricanes

John Arnold
08-02-2007, 10:13 AM
A family summer house in Rhode Island is getting a new roof. The roofer is suggesting a ridge vent, which I think is a good idea. My brother-in-law, who is a geologist and weather-freak, wonders if the ridge vent could cause the roof to be more vulnerable in a hurricane. By the way, the house is a two-story un-insulated shell - no attic. It gets awful hot up there on the second floor in the summer. Anyone share his concern?

Stephen Houmard
08-02-2007, 10:20 AM
During a huricane the roof will come, off ridge vent or not. Didn't Moses say, " Let my shingles breathe". I would go with the ridge vent.

Jerry Peck
08-02-2007, 11:02 AM
If you have a hurricane, the roof *should not* come off, not if it is properly strapped down, or the hurricane is of such force that it is beyond the capacity for which it was strapped to resist.

The ridge vent, on the other hand, will be long gone before the strapping ever comes close to be tested, leaving a large open slit in the roof for: 1) rain to get into, 2) wind pressure to get into, and now not only is the roof sheathing having to resist the uplift of the wind blowing over the roof, it must now also resist the uplift caused by the wind blowing against its underside - twice the uplift, no increase in nail attachment = loss of roof sheathing, which leads to the loss of most everything else.

Go back to the recent thread discussion on soffit vents - make sure there are plenty of soffit vents. That will give you good ventilation and help protect the roof from leaks and wind.

David Banks
08-02-2007, 11:54 AM
John I think this PDF came from same thread Jerry mentioned. Page 5 Moisture Control in Wet Cold Climates. Study indicates unvented attics have advantages in wet cold coastal areas. As Jerry says maybe soffits would be enough.

John Arnold
08-02-2007, 12:24 PM
Thanks all.
No attic, as I said. Second floor is open to roof. The house is really just a shell. No realistic possibility of adding soffit vents. I'll talk to the Rhode Island roofer about hurricanes, too.

Jerry Peck
08-02-2007, 02:28 PM
No attic, as I said. Second floor is open to roof. The house is really just a shell.

Oops, forgot about that part - all that means is that when the ridge vent blows off, it rains directly inside, does not need to go through the attic.

Apparently the house is just one big attic. :)

If you installed a ridge vent, how would you close it when you did not want it open? (You wouldn't.)

What would you do then?

I'll talk to the Rhode Island roofer about hurricanes, too.

Good idea as they will know how susceptible that area is to 'high winds' (don't just think hurricanes, think 'high winds'). 'High winds' would be sustained winds of 60 mph plus, and time to start worrying when they reach 75 mph plus (74 mph sustained winds is the bottom threshold for a 'Category 1 Hurricane', 45 mph is the bottom threshold for a 'tropical storm' ... 'tropical storm' winds can wreck havoc too if the structure is just slapped together.), and time to bend over, grab your ankles, and kiss your sweet butt good-bye when they reach 120 mph and over ... unless the house is specifically built to resist such winds, then you might be able to put that off until the winds are 140 mph and higher ... :D

From looking at the basic wind speed map in the IRC, it looks like most of Rhode Island is over 90 mph and under 120 mph.

A search of the NOAA hurricane tracks shows Rhode Island may only have had about 9-10 hurricanes going back to the 1800's.

Of course, though, Rhode Island is also 'not real big', almost like wanting to know how many have hit my county. :) *Each* hurricane most likely covered the entire state of Rhode Island. :eek:

David Banks
08-02-2007, 03:33 PM
The one big one that hit Rhode Island in the 30's put the city of Providence under water. Saw a special on PBS. One family floated across Narragansett Bay on their gable end and survived.

Richard Rushing
08-02-2007, 03:48 PM
Yea, they get hurricanes... but no big deal. You can carpet the whole state for $19.95.:D

Do to ridge vents anywhere a hurricane is possible. Especially a shell.


John Arnold
08-02-2007, 04:17 PM
Do to ridge vents anywhere a hurricane is possible.RR

Richard - Couldn't quite make that out. Are you saying not to have ridge vents anywhere a hurricane is possible?

Geoff Ehrman
08-31-2009, 08:45 AM
Hurricanes - no problem...Just install a ridge vent that has passed the "Dade County" code. They are tested upto 110 mph. Benjamin Obdyke offers a variety of rolled and sectional products under the "Roll Vent" and X18 brand.

Residential Roof Materials and Ventilation, Wall System Products (http://www.benjaminobdyke.com)