PDA

View Full Version : Venting a roof with no soffit vents


seaton
08-23-2007, 06:08 PM
I have found myself in a wierd situation. I am building a cabin, and the county adopted this new Wildlife Urban Interface. One of the things that it specifies is that I can't have soffits. My roof is TJ's (heavy snow load) stick framed up to a glue lam beam. I am confused if I can't vent the soffits, then how the heck does a person not root out the roof ?

Thanks
Steve

Don_P
08-23-2007, 06:57 PM
I think they owe you an explanation. You are bound by the rules you pulled the permit under. if they adopt new provisions after your permit issue date, they apply to permits issued after that date not before.

kadoka
08-24-2007, 08:46 AM
Here is what we used on our house and detached garage. We left the rafters exposed and these worked great

Raft-A-Vent RS-400

Here is the URL

http://www.cor-a-vent.com/ventilation-products.cfm

homebild
08-30-2007, 09:00 PM
I have found myself in a wierd situation. I am building a cabin, and the county adopted this new Wildlife Urban Interface. One of the things that it specifies is that I can't have soffits. My roof is TJ's (heavy snow load) stick framed up to a glue lam beam. I am confused if I can't vent the soffits, then how the heck does a person not root out the roof ?

Thanks
Steve

Chapter 5 of the International Wildland-Urban Interface Code requires soffits and eaves to be constructed for 1-hour fire protection.

This is no different than for any residential structure that gets built within 5 feet of the property line or another detached structure on the same lot.

The goal is to limit fire spreading from one structure to another, or in this case, from the habitat to the structure.

The IWUIC does not restrict one from having soffits. It resticts one from having vented soffits.

Attic ventilation need not to occur through eaves or soffits, however.

The International Residential Code, which your jurisdiction also likley has adopted, simply requires a minimum of 1 sf of ventilation for every 150 sf of attic floor space....and that the roof area be 'cross' ventilated.

Gable vents can meet this ventilation goal without requiring vented soffits as can roof or 'mushroom' type vents placed on the roof downhill low close to the eaves and uphill high near the ridge.

Both methods will meet the IWUIC requirements to prevent fire from being vacuumed up through vented soffits while allowing your attic area to be properly ventilated.

ezadmin
08-31-2007, 06:39 AM
seaton - I am assuming you have a cathedral ceiling and also assume you are going to insulate it? By framing with TJI's it is difficult to get any venting especially considering the Wildland Codes. You could look into a non-vented roof assembly or use the In-Vents, on the page kadoka recommended, with a continuous baffles to the peak. Gable vents are going to help with a cathedral ceiling either.
If you do not have a cathedral/vaulted ceiling and are going to insulate at the flattened ceiling line (such as a trussed home) - then the gable vents would be the best option. Just don't see many cabins framed with TJI's to a beam that have an attic space - which is why I assumed you were going to have a cathedral ceiling.