Roof Ventilation: "I am involved in a home purchase that the inspector ..." - Guest User (10/19/2004) | Ventilation | Archive

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I am involved in a home purchase that the inspector questioned the ventilation of the metal roof. An inspection by a respected roofing contractor, concurred he did not believe that the ridge vent was functional. There are no soffit vents or other visible venting systems in this vaulted ceiling. I have been told that not all contractors vent their metal roofs- it is the option of the installer. If there is no sign of a problem- it isn't one. I know that there are vent systems both above and/or below the sheeting in some metal roofs I have seen. The home is in a wet climate, and gets little or no sun. Furthermore it has only been used as an occasional 2nd home ever since the roof has been put on. How can I identify potential problems? Is there a way to vent this roof without replacing it? With all the talk about mold, I do not want to close my eyes to a future problem. Thank you for your help!		Guest User 10/19/2004	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/4377/find/
What you are describing, if I am understanding it correctly, is a classic situation where condensation could occur. Condensation, remember, occurs when warm moist air hits a cool surface. Using this as a full time residence will mean that the sir inside will be overall warmer and moister than it has been in the past. There are several unknowns here though. Is there solid decking (plywood) behind the metal roofing? Is there any air gap at all between either the decking or the roofing and the insulation? Is there a vapor barrier (sych as polyethylene) behind the drywall? Some deconstructive testing may need to be done in order to answer these questions. Generally, in this situation, one might expect to see some mold or mildew on the inside of the ceilings if a past problem has been present. This may not always be the case though as the mildew could be hidden. Are there any sources of excess moisture inside the home? Are all exhaust fans and plumbing vents and dryer vents vented to the outside? Is there any moisture in the crawlspace or basement? There is nothing particular to metal roofing, really, which increases the potential for a moisture problem. This all pertains to basic construction procedures, regardless of the roofing material type. As I had suggested earlier, feel free to call me at 1-800-543-8938 ext 201 if you would like to discuss this in greater detail. Todd Miller		Guest User 10/19/2004	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/4378/find/