Having wet sheathing covered with tarpaper or membrane will trap the water in the sheathing - very bad practice and contrary to industry standardss for roofing. Moisture from above. $500* Estimate to seal the roof deck on … Senior Engineer Manager at Icynene, John Broniek makes the case for the unvented attic assembly and why insulating the underside of the roof makes sense. Insulating a roof is perhaps the easiest of all the energy-saving home improvements. Clearances 1)Except as provided in Sentence (2), not less than 63 m m of space shall be provided between the top of the insulation and the underside of the roof sheathing. There have been isolated moisture related incidents that raise potential concerns about the overall hygrothermal performance of these systems. From the pic it looks like mold due to the lack of air flow. Frost and ice forms in attics when warm, humid air accumulates and condenses on the underside of your roof sheathing. Report: Attic insulation incorrectly installed and blocking soffit vents on North side of home. West Fraser is a diversified wood products company with more than 60 facilities in Canada, the United States, the United Kingdom, and Europe. In either case, you need to have the situation inspected by a qualified person. If You’re Insulating the Roof Directly. R327.7.5 Enclosed roof eaves and roof eave soffits: The exposed underside of enclosed roof eaves having either a boxed-in roof eave soffit with a horizontal underside, or sloping rafter tails with an exterior covering applied to the underside of the rafter tail, shall be protected by . As the other comment said, with normal exterior rated plywood one wetting, assuming your attic is well enough ventilated to dry the wood out in a few days, is probably not going to cause much damage to the sheathing. Note the added parapet exterior drip edges. I’m in the process of installing a metal roof over an outside deck. Even a few inches of damage could be of great concern due to the Cape Cod house style. To the touch, it was slightly oily.The other thought was an exhaust from over the stove/oven, but it appears to terminate outside the attic. Thus the firewall must run continuously from the footing all the way to the In 2013, Wiss, Janney, Elstner Associates, Inc. (WJE) was retained by an attorney representing the owner to evaluate and monitor moisture conditions at the underside of the OSB roof sheathing, as well as to design structural repairs. The quest for greater energy efficiency in buildings has led to increasing interest and need for insulation, improvements in HVAC equipment, more airtight construction, new materials and assemblies. He asks why the problem occurred this year, but not in … can sun get to the roof) you will have either frost or water collecting. Appears, due to this incorrect installation, mold is forming on the underside of the roof sheathing. All attic gable end walls now separate interior from exterior conditions and must be insulated and air sealed. By 2012, large portions of the wood structural panel oriented strand board (OSB) roof sheathing was found severely decayed from moisture collecting on its underside. Check the insulation for dampness. Generally, plywood roof decking that has gotten wet and had the shingles applied over it, if allowed to dry out, will not be seriously damaged by wood rot fungus organisms. When this phenomenon occurs, the sheathing or framing may become slightly wet on the surface. Increasingly, homeowners in the Pacific Northwest are noticing mold on the Install a closed-cell polyurethane spray foam applied to the underside of the roof sheathing at the joints between the sheathing panels and along all intersections between roof sheathing and all roof framing members. Looking for a little help here. If you choose to install open-cell spray foam against the underside of roof sheathing in Climate Zone 5 or colder zones, make sure that you include an interior vapor retarder. Those often are the underside of the roof. Depending on the temperature, and the insolation (ie. It remained wet during the time that the snow was on the roof and spots of mold began to grow on the plywood roof sheathing. Look at the underside of the roof sheathing and roof trim to make sure they haven’t gotten wet. Yet, that word is typically used to merely describe the flat cladding or finish covering of the roof overhang elements themselves. I performed an assessment for a recent home buyer and the home inspector they hired when they purchased the home said the fiberglass insulation that is touching the roof where the roof slope meets the exterior wall may cause condensation issues and needs to be pulled away from the underside of the roof. Roof leaks must be repaired from the outside to ensure the problem is corrected. This is the underside of the roof sheathing, plywood sheets, almost all of them were dark in color but a few had this on it, almost looks like it is charred from a fire, but nothing in disclosures. 5)Vents shall comply with CAN3-A93-M, “Natural Airflow Ventilators for Buildings.” 9.19.1.3. Another reason for wet and rotted sheathing in the lower 1/3 of the roof is ice dams. So a client of mine removed existing batt insulation from a rafter bay that happen to be touching the underside of the roof deck (no air space) and there was condensation on the rood deck. THE COST. The house was originally designed and constructed with no soffit, so there are … Unvented roof strategies with open-cell and closed-cell spray polyurethane foam insulation sprayed to the underside of roof sheathing have been used since the mid-1990's to provide durable and efficient building enclosures. From responsibly sourced and sustainably managed forest resources, the Company produces lumber, … The OSB got wet and rotted. However, when it is not practical to climb up on the roof to fix a leak, such as during the winter months, you can repair a leaky roof temporarily, from the inside, if you can determine where the leak is occuring from the underside of your roof. This approach works in all climate zones. purlins not less than 38 mm by 38 mm on the top of the roof joists. Some houses with open-cell spray foam installed on the underside of the OSB roof sheathing have had moisture problems. Bob discusses the advantages of hazard-resistant building techniques, specifically sheathing the roof, with Bryan Readling (from the APA). So the message here is to check your home carefully when ice dams form. But where does the moisture come from? A moisture meter confirmed that damp-appearing spots on the My rafters are in place, and now I’m getting ready to purchase and install my flashing and sheathing. If the temperature drops below the freezing point, often at night after the sun goes down, this moisture will freeze. Flat roof with parapet insulated from underneath with with spray polyurethane foam (2 lb/ft3 density) installed directly to the underside of the roof sheathing (Figure 1). Roof Approach One. The term most used in Architectural lingo and with the Building trade(s) is: soffit. Spray applied fire proofing is applied to the spray foam. Apply spray foam at the underside of the roof sheathing and at the wall perimeter to create an air barrier connecting the wall to the roof, and to provide adequate thermal resistance to prevent condensation. Investigate even when there doesn’t appear to be a leak. one of the following: Noncombustible material. Wet sheathing was found in attic area due to lack of venting However when he removed the insulation from the remaining rafter bays there was no condensation or discoloration of the wood deck. And now that the insulation has been removed, the spot that was wet … And when leaks inside your home develop, be …