During extreme cold temperatures, frost can build up on the underside of the roof sheeting (attic roof). Underside of roof deck soaking wet It wouldn't hurt at this point to install a few oscillating fans up there.
Wanted to add more cellulose but installer said it would make wet roof worse.
Underside of roof damp. In the loft there is no backing to the roof just the tiles so you can see the underside. When the water vapour percolates into the [unheated] loft space it has to condense on the coldest surfaces. Frost itself doesn’t do any damage, but once it melts, things get wet, and then damage occurs.
Mold growth will return if the underlying moisture issues are not addressed. Cold up here just now, but the temperature will drop further What is happening is the moisture in the warm rooms below the loft are allowing the water vapour to get into the loft space, water vapour is OK in a warm space [the rooms of the house] BUT??? There is black mold on the underside of the sheathing, and water dripping from the pointed ends of the roofing nails,” I’ve got a pretty good idea of what’s going on.
If you want to deal with the problem of condensation in roof space, you have to deal with these problems first. Fred C Coote of the Lead Sheet Association (LSA) investigates underside condensation and corrosion of lead sheet roofs, addressing issues including how and why corrosion affects lead sheet; This leads to the formation of damp spots on the surface of the roof.
Are often laid over eaves and applied to the underside of the roof, in contact with the roofing felt. These are the two major causes of the formation of damp spots on the surface of the ceiling. 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.
When open-cell spray foam is installed on the underside of roof sheathing, designers and builders need to pay attention to the RH of the air in the attic, or the roof sheathing can get damp. Any contact condensation will run down the felt and make the insulation damp.. Plywood is original – 49 years old.
This would condense on the underside of the roof covering and give rise to damp staining to all surfaces including the timbers.. Owners of agricultural buildings, man caves and horse barns all are worried about the corrosive effects of condensation. Combining these two techniques both limits the influx of warm moist air and also helps remove the damp air that slips through.
Make sure primary air flow paths from upper level ceiling to attic space are closed off and at least put some six mil poly over the exposed crawl space ground. Over the last 16 years I have installed new roofline fascia boards to hundreds of houses, I always install roof vents with each installation to help prevent condensation.This page is for those of you who suffer from loft/roof condensation. Moisture accumulation is most significant when outside temperatures are very cold because air holds less moisture as the temperature decreases.
I seem to have the same problem in that I insulated the attic two years ago and now it appears all the felt is damp with water droplets forming on the underside. When moisture gets into the attic, it condenses on the roof sheathing in the form of frost. Once the outdoor temperature rises, that frost melts and can mimic a leak.
The roof looks fine although a little weathered. Here’s how to fight back against the enemy within. This “leak” can be excessive when the temperatures dramatically change, as is.
The signs of corrosion and how to prevent condensation forming On going back inside the attic, the frost had melted and the underside of the sheathing was wet, not so much that it was dripping, but enough that it was damp. We're on the same page here, Joe.
Is My Roof Leaking or Is this Condensation? Keeping ducts within the conditioned space of a building is preferable to installing spray foam on the underside of roof sheathing. The result is that this roof has no problems and it has been over 10 years since it was installed.
What can I do about dampness in the attic?. Typically, this involves increasing the roof ventilation and air sealing the ceiling of the top floor. I inserted two roof vents (both sides)but they do not appear to be working… It is an attic conversion.
In addition, most historic buildings in active use will be subjected to an increase in humidity caused by modern lifestyles.. Roof Vents to Prevent Condensation. 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.
Inner plywood of roof wet. If there is excessive moisture accumulation in your attic it will condense on cold areas mainly on the underside of your roof deck. There were no areas where any water was pouring in but there were several areas where the tiles join that were damp to the touch.
To reduce the amount of radiant heat transfer, you can install a foil-faced. The Need for Roofs to Breathe. 2 layers of shingles.
We then vented that space through the roof deck as was the normal practice for roofing. There is a general way to deal with such issues. Although moisture problems in the roof assembly can be due to waterproofing deficiencies, don't neglect the effect of condensation.
When a GBA readers tells me, “I have a vented unconditioned attic that is damp. If you’re wondering how to prevent condensation under a metal roof, you’re not alone. Exceptions do exist though.
Not wet but some areas slightly damp. Proper garage ventilation (on the walls or roof) is essential to reducing condensation and helps maintain the balance between the air inside and outside of your home. But with proper design and maintenance principles, you don't have to sweat roof condensation issues.
The impact of condensation in post-frame buildings is very real. If your roof, deck, or insulation is developing water droplets, chances are your forehead is too. The sheathing at the peak of the roof was saturated with moisture.
Make sure you allow at least 1 inch of air space between the underside of your roof deck and the face of the batts. If you want to lower the risk of damp OSB, choose closed-cell spray foam, not open-cell spray foam, to insulate the underside of the roof sheathing. After the downpour yesterday i had a look in the loft to check for any leeks.
There were also several issues with the intersection of the roofs where the 2 apartments meet. Melting frost can lead to deteriorated roof sheathing, mold on the roof sheathing, wet insulation, and water stains on the ceilings.