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TOPIC: Ventilation

enough ventilation?

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I am replacing my tar and gravel roof with a standing seam metal roof. The house presently has all hips with only soffit vents. To this point there has been no discussion regarding a ridge vent, but other messages seem to indicate that they are required. Do I need a ridge vent? Does blowing rain pose a problem with a 3:12 pitch? How much should a ridge vent add to the cost?
Guest User

3/17/2004
I truly need a bit more information. Does your home have an attic or vaulted ceiling. If it has an attice then the ventilation has been restricted for years. If yoy have a vaulted ceiling it was probably constructed with the rafter void filled solid with insulation and the soffit vents only vent the soffit. Regardless the new building code calls for ventilation. If it is an attic, then make sure the soffit vents are free into the attic, cut the ridge open and install aridge vent. It should not be too expensive as all they need to do is use a profiled vented closure and use the standard ridge cap. This mesh has been tested for wind driven rain profided it is 3" wide. If it is a vaulted ceiling you will need to choose and install a roof system that stands off on strapping and allows for 1" min of free air to move from the eaves to the ridge. The ridge is vented as above without opening the ridge and the eaves are vented with mesh.
Allan Reid
Dura-Loc Roofing Systems, Inc.

3/18/2004
The house in question is in San Jose, California. It is an "L" shaped house with a 4 ft high attic over the original house and around the turn; then butting up to a vaulted section starting half way down the perpendicular leg. If I use strapping over the vaulted section will I need to continue it over the entire house to maintain a level ridge? And once again, what percentage should that add to the entire cost of the project? (approximately 2600 sq. ft.) Would an attic fan be simpler and cheaper?
Guest User

3/18/2004
In your area the ventilation is going to make your home much more comfortable in the summer and by choosing a lighter colour you should be able to save around $300 in utility costs. California is in a flux with building codes. The Unified Building Code was merged into the new International Building code and the state adopted the NFPA 5000 code last year however your govenor has a freeze on it. Regardless, bth call for ventilation so you are required to comply when you get your building permit. Attic fans have proven to be poor ventilators and under the NFPA code you must provide equal ventilation at the eave and ridge. Hence they do not qualify. Typically they just short circuit the air from the intake to the fan. As an association we are not allowed to discuss pricing so you will have to get that from your contractor. As previously stated with the style of system chosen it is a matter of upgrading the closure strip from foam to mesh. You can price the mesh at most building supply places who sell it under the name cobra vent in 75ft rolls. Additionally you will need about 80 ft of 1" board per sq to strap vertically and there should be minimal labour differance. Hope this helps.
Allan Reid
Dura-Loc Roofing Systems, Inc.

3/19/2004
I just bought a little cabin in Upstate NY where the winters are pretty tough. The hous has a layer of asphalt that has seen its day. I'm thinking about metal and have this question. the front room is vaulted, there are no soffit vents, only one vent in the middle of one side of the roof. should i have a contractor use battons to raise the roof prior to installing the metal roof? My neighbor says that the snow never sits on this part of my roof, does that mean I'm losing a ton of warm air and would venting help? Thanks, Jon Richer
Guest User

6/1/2004
Creating a vented air chamber will help with energy efficiency, particularly if you make it deep enough to add some insulation and still have at least 1" clear vented space on top of that. It will also help with avoiding moisture and condensation problems inside the cabin. This could become very important down the road if anything is done to make the cabin "tighter" in terms of siding, house wrap, new windows, etc. The type of metal roof you choose will determine whether you can install over battens or if you will need to put down roof decking.
Guest User

6/1/2004
Hi guys, I have been pouring over these forums searching for facts and answers. I have asked different questions in other threads, but another one I have is with Versa-vent and simular products. How long can a home owner expect those products to stay free and clear from debri and other objects from plugging them up? I have contacted the manufacturers and same as always, they never seem to be able to answer the tough questions. I started looking at these types of products when traditional ridge vents, like Plyco Ridge vents, been having reverse air flow or w/e it may be to allow snow coming in. I understand the idea of having equal air flow from eave to ridge or even more air flow out the ridge. Some of our pole buildings are pretty large 80x200 plus. So to try and prevent these problems I have been considering these other products to use like Versa-vent. When you call and ask about them plugging up, no response or no idea is what I seem to find. Is there any proven research or studies I can go and read up on that have tackled these kinds of questions? My questions stem from me wanting to make sure my customers have the right installation and performance. I see to many times that people, contractors, manufacturers, and suppliers (me) selling these products just to make the buck. Whats about protecting these home owners from improper use or installation? At the very least, arm them with the knowledge of potential pitfalls and problems to watch out for. Granted, building codes are around for these very reasons, but improper installation and hidden problems still happen. Is there a site or source that taclkes these probelms with research and proven data I may draw conclusions from? Thank you Please email me at [email protected]
Guest User

5/1/2009
Gosh, I don't really know. It seems to me it would have a great deal to do with the environment. Have you seen problems with them clogging? If so, from the inside or the outside? Todd Miller
Todd Miller
Isaiah Industries, Inc.

5/2/2009