Driving wind and roof vents


#1

How to prevent water intrusion into the roof vents? Out home is less than a year old and we have ceiling cracks due to water entering the roof vents. Lomanco 750 slant back vents. We live on the Colorado high plains on an exposed ridge and high winds are typical and can come from anty direction. The ceiling leak was after a moderate snowfall. I have been told that any roof will have water intrusion with high winds. If that is the case then the basic purpose of a roof has been forgotten! I would rather have no roof ventilation vents and take the risks of heat build up than having my ceiling falling down. We have had two roofers evaluate the roof. The roof is in great shape, exceeds code, flashing and shingles in great shape. A quality job except water is coming in the roof ventilation vents, soaking the blown in insulation and ruining the ceiling. Insulation was blown in over the soffits vents, but the roofer thought there is still plenty of air circulation. There are enough soffits vents and roof vents although the soffits vents are on the opposite side of the roof from the roof vents. One roofer thought that was an issue, but the other roofer thought that was not an issue. Both roofers felt it would be better to have roof ridge vents rather than the type of vents we have, but neither thought it would fix the issue with water intrusion with high winds. Need recommendations please.


#2

Carla,
There are roof vents installed on ocean side of homes on the Oregon coast and wind blown rain is rarely a factor. Downplaying the soffit vent being covered by insulation concerns me but I’m not there doing the visual inspection. First thing is to make sure the leaks show up in rain/wind conditions exclusively.


#3

The leak appears to be from the build up of snow and not from wind driven rain, according to your post. The 750 is one of the better vents. It has the Texas Department of Insurance stamp and the Miami Dade stamp. Both of these are for wind driven rain. I believe the last time I looked at the box it was for 110mph winds. Although this vent is touted a self flasher, professional roofers don’t believe anything is self flashing. When I install these, I seal each shingle to the flange. The complete perimeter. I think I would check to make sure the shingles are sealed to the flange. In your area, it may be watershield. We used to do that here, but we found that every now and then, the watershield didn’t do its job and a leak would occur. This is one of the reasons I don’t believe in the GAF crap about putting watershield around vent pipes and chimney flashings. If it gets on the watershield, it runs under the shingle and finds the nail holes. Thus, a leak. I seal every shingle to vents.
If the shingles are sealed to the flange, it could be that somehow, snow built up inside the housing, as to go higher than the pipe that is inside the 750. I don’t deal with snow in southeast Texas, but logic is the same. Heck, we close every government business, school,freeway and Sonic if it starts sleeting.