Attic Ventilation

Attic ventilation: So this attic has insulated floor and spray foam everywhere else as you can see in pics. The spray foam has sealed everything and now no ventilation. Is this considered acceptable? The ridge and soffit vents are now blocked and I have randomly read that now its believed if a space is sealed properly no ventilation is needed. Is there any input on this? Is that being attempted here or is this just bad and ventilation is needed?





What have you been doing since 2008? Try this:
Conditioned attic info

Nice link thank you

It is called a “hot roof” and it is becoming (is) an approach that is being embraced more and more to create a more energy efficient home. There has to be a way to exchange air however, so you will want to look for an air to air exchange system (warm air going out and warming the cool air coming in). Most builders are exchanging air with an extra bathroom fan some place, on a timer (sometimes in the main hall, upstairs or even in a closet). Or with the existing bathrooms on a timer. The best approach to the timer application is a timer in the basement, tied to the bathrooms. As human behavior proves that people will not use or will shut off or disconnect the fans because they feel like they are wasting heat or energy. Homes need to exchange air. I am a fan of traditional venting approaches. I feel like hot roofs have the potential to affect people"s heath by keeping “stale” air in the home, trapping radon more readily, etc. Not to mention, allowing mold growth more readily if the air becomes too humid. All of this, because people won’t run their fans. The fans should run at least 30 mins per day. I did an inspection a few weeks ago and all of the bathroom fans (3) in the home were running at the same time when I arrived. They were on a timer in the basement.

We in Canada have HRVs for that purpose .

Sometimes we see new technology implemented in attic ventilation/conditioning. The possibilities are endless. I had such a scenario yesterday. After 6-10" of snowfall the night before, this jewel displayed indications of a problem when I arrived. Note the snow melt area on the roof. Was it a lack of insulation or air migration into the attic? Stupid me!!! I should have known that there was a dehumidifier running in the attic!!!:p:p

Dehumidifier in Attic.JPG

Polish Conditioned  Attic.JPG

That will do it thanks for the pictures … Roy

Just make sure the spray foam is open cell (about the consistancy of sponge cake) and not closed cell. Closed cell is OK, in and of itself, but peo9ple being people and not changing their roof covering intil it actually leaks into the ceiling, closed cell foam will allow water to accumulate in the rafters, cause rot and, eventually, collapse.

Hope this helps;

Isn’t the floor insulation usually removed when this is done?

Not is a) the insulators are lazy, or
b) the homeowner does not want to pay extra.

In either case, it makes no difference.