No Attic Non Ventilated Rafter Space

Following this closed cell spf was also installed to the underside of the roof deck.

No attic non ventilated rafter space.

No interior vapor retarders are installed on the ceiling side attic floor of the unvented attic assembly 2009 irc. At these low levels the moisture has a negligible effect on the strength and structural integrity of the wood panels. All of these materials are supported by quality assurance testing capabilities that. That said air resistance and interference such as vent grates reduces the area of true ventilation.

If there are asphalt shingles on your roof the attic must be ventilated to comply with the terms of the manufacturer s warranty. Your actual living space is sealed and insulated at the attic floor the attic is outside this envelope. Generally speaking you need a ratio of 1 300 where for every 300 square feet of ceiling space you need 1 square foot of attic ventilation. However if moisture is able to enter the unvented attic space it may lead to roofing panel issues.

Unvented roof assemblies should be insulated either with air impermeable insulation rigid foam or spray polyurethane foam or with a combination of foam and air permeable insulation. We have the capabilities to spray and inject a variety of foam systems to achieve a high r value while providing both effective vapor and air barriers. In other words the entire vent opening doesn t count as vented space. Foam tech creates superior insulation and environmental control solutions by installing safe cost effective and environmentally friendly polyurethane foams.

Where wood shingles or shakes are used a minimum inch vented air space separates the. A vaulted roof offers open living space directly below the rafters because there are no horizontal ceiling joists. Rafter vents or insulation baffles install in any rafter space to create narrow gaps that direct fresh air from the soffit vents to the peak of the roof. The dormers and the attic space over the outside porch were sealed off from the rest of the attic by making a wall of plywood then insulating the wall with closed cell spf.

No interior class i vapor retarders are installed on the ceiling side attic floor of the unvented attic assembly 2012 irc 3. Don t avoid ventilating your attic for fear you re letting cold air into the house. However when roof. The answer is rafter venting.

If you don t want to use sips or nailbase read this article tolearn the four basic approaches to insulating unvented roof assemblies. Although there is no separate attic to vent air circulation is still necessary. In cold climates the primary purpose of attic or roof ventilation is to maintain a cold roof temperature to control ice dams created by melting snow and to vent moisture that moves from the conditioned space to the attic ventilation acts to bypass the vapour barrier created by most roof.