# attic vent and insulation



## handyman_squire (Aug 5, 2012)

I bought my house last year and when it started to snow and get really cold I noticed that there was a ice dam forming on the roof. I went up today to see what was up there for insulation and if I needed to add more. Well to my surprise there is quite a bit of it up there. The previece owner however put it overtop of the soffit vents. So today I moved it all away from the soffit vents and had a quick question about if I should add another vent on the roof or if the one thats there now is good enough. the living space that the insulation is over top covers roughly 500sqft. I attached a picture of what the vent looks like. Thanks for your help


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## HomeSealed (Jan 3, 2008)

I like roof vents as opposed to ridge vents for efficiency, but most importantly the qty of insulation may not affect your ice damming as much as proper air sealing. You are probably still losing a fair amount of heat through the attic if it was never air sealed... Good move to clear off the soffit vents. Ideally you want baffles installed to them to allow flow, then you can insert dams.


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## handyman_squire (Aug 5, 2012)

so you think I should install a vent some where at the peak of the roof? To be honest I couldnt tell you if its air sealed or not the house is 40+ years old.


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## joecaption (Nov 30, 2011)

#1 No one knows where you live because there's no location in your profile.
Questions like this need a location.
What's there for soffit vents? No gable or roof vent can work without enough soffit venting.
Simple enough to see if any air sealing was done. Pull back some of the insulation to see if it was done around any plumbing, wiring, ceiling fixtures.


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## handyman_squire (Aug 5, 2012)

sorry about the location I live in New Brunswick Canada. This is what is there now http://www.kent.ca/kbs/en/product.j...19&prdId=7187410&skuId=7187410&catalogId=1519 
spaced about 4 inches apart all the way down. As with the air sealing would there be plastic or something around the ceiling fixtures?


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## SeniorSitizen (Sep 10, 2012)

Forget attempting to air seal an old house or even a new house that should have been air sealed at the time of construction and even then there are very few contractors that's even willing to attempt it.


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## handyman_squire (Aug 5, 2012)

okay so I am planning on installing the baffles but it is very tight fit down there. Is there anything special about putting them on? or just staple them on?


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## Fix'n it (Mar 12, 2012)

Fairview said:


> Forget attempting to air seal an old house or even a new house that should have been air sealed at the time of construction
> 
> and even then there are very few contractors that's even willing to attempt it.


bad advice. this can and should be done. yeah, it probably will be a major pita. and getting every last leak is probably not going to happen. but the results will be well worth it, even if you get only most of the leaks. am there, doing that.

few, yes. but there are companies that this is their business.


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## SeniorSitizen (Sep 10, 2012)

Good luck because you'll need a lot of it. And don't forget to seal all the drywall where it connects to the top plate both exterior and interior walls. That wasn't done when the house was built and there will be a few hundred feet of that. Or go buy several of those outlet cover / air stopper / insulator things in an attempt to stop cold attic air from descending from the attic. :laughing:


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## Fix'n it (Mar 12, 2012)

Fairview said:


> Good luck because you'll need a lot of it. And don't forget to seal all the drywall where it connects to the top plate both exterior and interior walls. That wasn't done when the house was built and there will be a few hundred feet of that. Or go buy several of those outlet cover / air stopper / insulator things in an attempt to stop cold attic air from descending from the attic. :laughing:


yeah, no doubt, its a battle. but its one that should be fought.


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## handyman_squire (Aug 5, 2012)

well there is no way that I am pulling all the insulation out of the attic and air sealing it I dont plan on living here for the rest of my life. Like I said its a 40+ year old house so I dont expect it to be air tight and a little heat loss is fine. Just trying to get better air flow in the attic then what was there before.


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## Gary in WA (Mar 11, 2009)

Any air sealing will be an improvement, as said. Anything said counter to that is wrong. "So what to do? Today, the answer is an easy one. Air seal the attic and vent the attic. Make sure that moisture laden air does not get into the attic from inside the house and make sure that if any moisture does get into the attic you remove it by ventilation. But the precedence is important – air sealing is more important than the ventilation." from;http://www.buildingscience.com/documents/insights/bsi-035-we-need-to-do-it-different-this-time

Start air-sealing in the cellar (bring it up to today's minimum fire/safety code at least for your family); http://www.wag-aic.org/1999/WAG_99_baker.pdf

Add more exhaust ventilation per attic square footage; http://www.airvent.com/homeowner/products/intakeSoffit-specs.shtml Sounds as if the intake is acceptable, do the math first and let us know the NFVA....

Gary


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## HomeSealed (Jan 3, 2008)

Fairview, any legitimate insulation/ home performance company does retro air sealing and insulation jobs on a day in and day out basis. The only guys doing "blow and Go" insulation anymore are hack roofers that should not be offering that service. I'd also strongly recommend an energy audit. You can easily seal a home too tight if you are ambitious which could lead to some dangerous circumstances particularly back drafting appliances.


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## handyman_squire (Aug 5, 2012)

What exactly is involved when air sealing is done?


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## Fix'n it (Mar 12, 2012)

handyman_squire said:


> What exactly is involved when air sealing is done?


first, you don't have to remove any insulation from the attic. but you will be moving some of it out of the way.

get a can of spray foam. look at the house, you are looking for anything that will go from inside the house, into the attic = pipes, wires, chimney, whatever.
and look around load bearing walls = my top plate interface into the attic had issues. someone had drilled holes for wires, but there were no wires to help find the holes. 
basicly, you are looking for ANY way that air can leak into the attic . even drywall cracks.

then move the insulation out of the way. first, to see any hole. and brush the area clear to give the SF something to stick to. 

then you just fill the void with the SF, and put the insulation back in place. 

how do you get into the attic ? if from inside the house. that has to be sealed tight with weather stripping. and some insulation on top of it, if possible.


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## handyman_squire (Aug 5, 2012)

The hatch to get into the attic is in the garage, which I don't heat in the winter so I dont think it matters if its weathered stripped or not I have another question but will post a picture when I get home instead of trying to discribe it.


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## handyman_squire (Aug 5, 2012)

Another thing that I have been wondering since I moved into the house. Under are kitchen dining room and loving room (the part of the house where I have been up in the attic) it has a crawl space. There is no insulation in there at all should there be insulation in there too?


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## Gary in WA (Mar 11, 2009)

Yes, R-value per location. The first inch (R-3.6) gives a 80% reduction in heat flow; http://www.google.com/url?sa=t&rct=...VjgAkW8XzKgQkGg&bvm=bv.44442042,d.cGE&cad=rja

Gary
PS, air seal first.


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