Had a energy audit and found ice in attic where I did not have soffit vents. Spent a miserable day putting in soffit vents and
insulation baffles in the attic. In one day most of the ice was gone.

Have soffit vents and gable vents with ridge vent. Have
heard where having both soffit and gable vents creates short ciruiting. So closed off gable vents. What are others doing
in AK to prevent roof issues?

The house I am in did not have any venting last year and there were moisture problems. Gable vents were put in this summer and so far things are good. The reason given out here for no venting was the constant winds. I do believe a house has to breath somehow or problems will devolop.

The house I have back in northen Michigan has both soffit, gable, and ridge venting and I had no moisture problems

Another source of ice in the attic is caused by attic bypasses. This is where hot air is allowed to escape the conditioned air envelope of your heated space. The large amount of air cannot be dipersed by the attic venting. Examples of attic bypasses include gaps in the vapor barrier around electricle boxes for ceiling fixtures, gaps around plumbing vents and soffits over cabinets or showers. I had a huge bypass over the soffit in a bathroom shower. The dumbazzes that sheetrocked did not put any rock over the top of the soffit. Then the dumbazzes that insulated merely stretched vapor barrier over the top of the soffit and blew in insulation. Staples and plastic did not support the weight of the insulation. I had an impressive pillar of ice that stretched from bathroom ceiling to the roof. Also, make sure your exhaust fans are vented through the roof and the piping is air tight.

Yes, this is the most current building science, in my opinion. I'd reccommend stapling 6mil plastic sheeting to all ceilings of new construction, then nailing 1x4's over the sheeting to have something to screw the drywall to. Nail the ceiling boxes to horizontal 2x4 blocking and seal the hole for the wire with expanding foam. This helps minimize the "stack effect" in a home.

Down here in Colorado we have this dehumidifier called the sun ...

Another cause of improper ventilation is covering the soffit vents with insullation. Many believe the more the better but you need the attic to "breath". Between the siffit, ridge and gable vent you should have more then enough ventilation in the attic.

A local motel here was built with the swimming pool space vented solely into the attic space. Can we say collapsed roof and ceiling the first winter.

A lot of sub-par building goes on here in Alaska. I know, you are all surprised....

Probably the best way to build for a cold climate is to eliminate the attic entirely and have a vented cold roof. IE, this can be done with 4-6in of polyiso or DOW board on top of a T&G board ceiling. Then nail sleepers with pole barn nails to the ceiling beams/purlins. This space only is vented from the soffit to the attic. Classic Post & Beam in NY used this method and it had held up well

A slightly more expensive, but less labor intensive method to achieve this would be to simply use stress-skin panels and install the sleepers on top of them and deck and shingle/roof.

Hot roofs and heat trace are all the rage here....

You want your attic space cold and well ventilated in the winter. Ice shield and heat trace on the eaves is a good idea to prevent ice damming. Frost is caused by the heat going thru the upper ceiling and going thru the dew point in the attic space. Good insulation and ventilation keep the top of the ceiling surface at, or below, freezing.

Another issue that I'm having a hard time with (and seems to be the rage with energy auditors) is a sealed crawl space under the house. No foundation vents and then a air "conditioning" system. And I don't mean cooling, but a humidity control and/or air exchanger. Anyone run one of these and have an opinion?

When I lived in AK as a young man I barely knew how to build a doghouse, after moving the the 48 and learning to build quality homes, and seeing pictures of stuff that gets built up there, I whole-heartedly agree.

An engineer buddy of mine told me about a house some knucklehead built north of Fairbanks. It was slab-on-grade, like they do in Florida. Everyone told him he was an idiot but he scoffed. The house literally broke in half. The students from U of A would come out to see the carnage.

Our house was built back in 1978 and they put in a big vent pipe with the rotating cap to vent the attic. 2 years ago we had our roof reshingled and we had them install proper roof ridge vents and got rid of that stupid pipe. Now the attic seems to breathes better.

I do have one question though, I just remodeled our master bath a few months ago and put in a nice quiet Panasonic vent which vents out of the side of the house, above the attic. The vent cover keeps freezing open whenever we use it and I have to close it manually. Is there something we can do to keep this from happening?

Have soffit vents and (****gable vents****) with ridge vent. **** cant have both- the gable has to go ...a bit late with that info i am.

They built crap everywhere...but alaska and canada are lite years ahead in proper building know now...the trouble is some folks don't have to follow them - and don't.....

There are a lot of options for dampers on vents... I prefer the floating balls.

Insulating the pipe right to the vent will keep the vented air warmer and slow down the frosting at the vent.

If you have a louver style a counterweight (small machine screw should be close to right) can be run through a slat and adjusted to weigh just enough to close the damper when the fan goes off.

We haven't done it yet but are thinking about it. We currently have a crawlspace w/ batt insulation in the rim and poly over the dirt floor. We're considering spray foam in the rim and "industrial" batts on the walls with the poly tucked under the bottom (and probably taped at the seams/overlaps.) Basically you're continuing your conditioned space down about 4'. We do have a couple of finned sections of hotwater baseboard in the crawlspace already. We haven't had moisture issues here in Chugiak with the current set-up but we might need some sort of a vent/exchanger if we change.

We have one that has a single louver in it, but never heard of the vents with the floating balls (there's a joke in there somewhere) but that sounds like the ticket.

Going to make changes this coming spring which I think will illeviate this problem too.

There is a book about building practices in the arctic - I believe it is called "Northern Exposure". Spenard builders used to have them up by the registers. Great insight into venting, vapor barriers, cold vs hot roof designs, etc.

Not sure who I loaned my copy out to last, but haven't seen it for a few years.

It was well worth the $40 or so it cost!!!

Found biggest air leak in garage where forced air furnace exhaust vents outside. Tough to seal as it goes out at an angle and not create a fire hazard. Local fireplace store had a fireproof insulation.

Using a fabric cover over 4" foam block to seal heat loss through skylight no light in winter any way. Stupid skylights those that leak and those that have not leaked yet are the 2 common types here in AK! Have a drop roof between 2 roof lines
with a skylight. Heat loss in winter melts snow that drips on
deck, house entrance, a real pain in the winter. Insulating skylight keeps snow on roof and ice off stairs.

Lots of heat loss on outside wall plugs and switches which are easy to deal with and find in cold temps. Now trying to tighten heat loss on any ceiling penetrations, light fixtures.

I've installed over 30 Velux skylights, a few in upstate NY and the rest in the SE. I've had exactly one leak, and only in 50+mph winds.

The problem with skylights leaking in AK is that people up here love to have flat/low pitch roofs with poor insulating qualities. The snow sits on it, melts, and the weight of the ice/snow pushes the water through any crack and crevice, no matter how well sealed.

I live in Anchorage, and I see new houses going up that have no wind barrier, no vapor barrier, and 1/2" gaps in the T111 siding that are filled in with caulk. All this for $325k. You start throwing in other things like no drip edge on the roof, 2x4 walls, and inadequate ventilation, and then people act all surprised when their house starts falling apart in 10 years. "Oh, that's just the way it is up here, because our weather is so extreme!" has been told to me DOZENS of times.

Oh, and you gotta love the 6" soffits!

ATV, I'm not sure I agree with your soffet/gable or soffet/ridge. You might have to explain this to me. In my house I have gable, soffet, ridge vents and fans. Since we use and want the heat only while it is contained within the house, after it leaves the insulation I want it out of the attic ASAP. The reason I have all 3 vent types is snow can cover the ridge vents compromising the convective air flow. This is where the gable vents are a back up. The type of insulation can also be a factor. Blown in type can be moved around within the attic durning high winds. It is not uncommon to have a big pile in the center of the attic and bare areas around the edges.

I'm not real fond of the tyvex type house wrap, but prefer tarpaper. This is another topic.

Pak, the only way to know for sure is get in the attic with one of those smoke pencil things and analyze what's happening. The "problem" with the gable vents is the air may not be flowing up from the soffets. This can overheat shingles and induce heat-related failure. I wouldn't think that would be a problem in your area. Worst case scenario would be to block of the gable(s) for the summer and open it up in the winter.

i have a feild guide from ccr i will see if i can post it...show how the air moves in the roof....btw i have built a 5 star home (i=me driving every nail -sold it for 320$$$) in this case and i'm going for 5 star+ this go around.......1/2 mil tag going on this one....

When we built our house we had the same issue. Our answer was to place roof/attic turbines at the peak of the metal roof. We installed 2 and even on calm days they passively spin and remove any trapped heat and moisture. It was low cost and worked fine.

Walt

I'm shocked that code allows a 2x4 wall up there. 2x6 would be minimum, IMO. I'd want nothing less than a spaced double 2x4 wall in the interior.

Nothing shocks me anymore....

pm sent.

Here on the coast of Washington, there is an old legend repeated by local native elders that speaks of this "sun". Of course, like most legends it has not been observed in recent memory and cannot be confirmed. Few lend any credence to the story but it is useful for scaring children around the campfire.

I myself....have seen "the great heat tab" in the sky ...(for less than 2 hours today)...all hail the great heat tab!

That is correct, reading to the end but there it is.

Here in RI. We got a foot of snow yesterday! It's code to have both ridge and soffit. They are supposed to work together. I have gable vents too. Since I wrapped my house in vinyl, I figured I couldn't be too careful.

That's the problem, gable vents, plus ridge vents, can cause short circuiting, air flow needs to be uniform and even. Our winters are so long problems can result.

Now need to vent bathroom fans to gable ends, one of the fans vents to eaves.

I was sent some materials from a fellow poster which have some air flow patterns for various attic/roof vent scenerios. I have gable, ridge and soffit vents. Because my ridge vents are often covered with snow I am going to leave my configuration as is. After many years I have had zero issues with my roof. Lousy venting is sure a PIA.

I cut a doorway into my back gable for easy access.

The ridge vents get buried for extended periods when we get snow.

My ridge vents get buried also, but I have shoveled around them in heavy snow and found they had air pockets open to the ends and were ventilating.

Would a smoke bomb in the attic help figuring air flow pattern?

A fire would eliminate most of the ice too!

Git R done!

Ridge vents don't do well here when the wind blows. One ends up with considerable snow blowing up the roof and in. When the attic warms we know where the water goes. Most end up filling them with foam.

Funny, we have far worse conditions here on a regular basis and they work just fine. We just had a hurricaine force storm a week or so ago and it was at least the fourth of the winter.

There are flow traps built in and they have been pretty well engineered to suck air out rather than blow...

Does anyone have a recommendation for an insulation contractor in Anchorage? I have received a couple of quotes, but both of them were much higher than expected.

I originally thought I would do the insulation work myself, but after a few hours in the attic, I have decided that I never want to go up there again.

If the temps in the attic aren't in the 100's, and you've got no black widows up there, then I just can't see what could be the problem

Dan,
What's your time line? The guy that did mine winters in Florida, but should be back before too long give a call if you're interested. --- Mel

Dan I know the feeling I dread going up there, but better in the winter. Make sure they do not create issues blocking soffit vents. And mark your electrical and vents for future reference.
Do you have a good vapor barrier?

Carlos inc. (yeah, I know...) did a good job of blowing in R49 and properly installing soffit baffles.

..... please pay the snow birds to just fly away........

Never really thought of him as a snow bird, He was one of my contractors for about 30 years, has a house in the sticks out by Palmer and has been going to Florida for a couple months the last few years to keep his wife happy. Wish I could afford to do so. The older I get the longer the winters seem to get. --- Mel

My problem with going into the attic is space related. I have a fairly low-pitch roof, and there's just not enough clearance for me to get to the edges to properly install the baffles.

With some help, I got baffles installed in the roof over the garage. I think I can finish that area without much issue, but I'll call and get another quote for just the roof over the house. That ought to save me *some* money.

Mel, if you could, please send me his contact info. Vek, I'll call Carlos as well. Thanks, guys.

Dan, I don't remember if you have wood or aluminum on the underside of your soffits.
If they are aluminum, taking the aluminum down should allow you to install the baffles from below. That's what I did on our house last year when we added insulation.
I didn't take all of it down, just enough to get a couple of baffles in, and then slid some remaining ones down to reveal more spaces. When I got to the far end I put the pieces back in to button it up.

Me too, Mel. There is something to hunting and fishing where you don't need to 'layer up'

Yes me to, I think I will go to Kona Friday for a couple of weeks!

Seems my Ice in the attic is gone!

my road looked like that a few days ago!

A tad more solider now.