Basements, Attics and Crawl Spaces - Attic ventilation with (potentially) blocked soffit vents

We live near Chicago and recently bought a 55 year-old, ~1200 sq ft ranch house with a relatively low roof. We are trying to install more insulation in our attic (there is currently ~3" of blown-in insulation). In the process, we found all kinds of references that you should not block the soffit vents, need to maintain air flow, etc.

While we have 14 soffit vents visible from the outside (each is 2 panels each 4" x 8"), the vents do not seem to have direct flow into the attic. There is a vertical pressed wood board mounted between the rafters which we initially thought was blocking the direct air flow (the pressed board is pretty much flush with the roof). This board is basically an upward extension of the wall, so the soffit area is apparently a separate triangular channel all the way around the house. In one location this vertical board is missing, and we could take pictures down into the cavity. But it looks like there is a board laying directly on the soffit. So, we used a small probe through the soffit vents from the outside and it looks like they are probably blocked by a board as well. When we tried using a leaf blower to force air into the roof through the soffit vent, the person in the attic could smell some fresh air but could not detect any kind of additional air flow either visually (i.e. no cobwebs or insulation were moving) or with their hand.

So, what do we do now? Since the soffit vents are apparently blocked, should we worry about opening them? Or should we assume that since the house is 55 years old (the roof itself is at least 7 years old) and the roof is in good condition, that we should just leave it as is and just go about putting in our attic insulation? Or is the air flow something that is critical and we should remedy before putting in our insulation?

Our original plans for the insulation were to put blow-in insulation to finish filling up to the joists (another ~3-4" of blow-in), and then rolls over the joists. We were going to use the rolls so that when we want to put up additional ceiling lights, etc we can roll up the insulation to find the electrical conduits and the joists to walk-on. This issue with the soffit vents has made us question whether we should be installing the insulation ourselves.

Welcome to the forums! Pictures would be great, not only of the one bay, but of a couple of the other bays so we can see what has happened. You can post them on a site such as photobucket.com and copy/paste the IMG code to your reply post.

Hi Katie, and welcome to the forum. Several issues here. Some pictures would help. http://forum.doityourself.com/electrical-c-d-c/400914-how-put-pictures-your-post.html
Venting is highly recommended, especially in a cold climate such as yours/ours. Condensation and ice dams are the issues.

Before you add more insulation, seal off all air leaks, such as around vent pipes, chimneys, and all electrical wiring. Check your recessed light to be sure they can be buried in insulation. What you want is IC (insulation contact) rated and air sealed.

You will need to find a way to open up the soffit vents, place baffles to maintain an air space below the roof deck, and make sure you have enough gable or ridge venting to correspond to the soffit venting.

Some pictures will help

Bud

Thanks Bud and Thanks Chandler
Here are some images. It is kind of hard to get up there, so these are the best pictures my husband could take.
http://pwp.att.net/p/s/community.dll?ep=87&subpageid=345619&ck=
Images of Attic and Soffits (http://pwp.att.net/p/s/community.dll?ep=87&subpageid=345619&ck=)
The images were saved from a pdf (I don't have the images), so the text may be difficult to read.
But above the first image is:
From the outside, it appears that there are regularly spaced soffit vents in the overhang around the entire perimeter of the house.
Above the second image:
Viewed from the attic, there is a vertical pressed board that blocks access from the attic into the overhang and soffit area. These vertical boards block access around the entire perimeter of the attic with the exception of about 12" (see next image).
Then the third image is:
In one small area, the vertical particle board is not present, and this is a picture down to the soffit panel. The soffit panel appears to be solid wood.

I hope these images and text help.

I'm starting to get the picture:). Ok, It looks like you can at least reach the board that is blocking each bay. One option would be to drill some holes in it. Just be careful not to drill right through the roof on the other side.

For the soffits themselves, if you can easily remove the covering there might be an option of opening holes right above the current vents. Check to be sure that already hasn't been done.

They also make 2 or 3 inch pop-in vents where you could drill a hole in every or every other little panel and install new vents.

Let's see what Chandler has to say.

Bud

Thanks Bud,
Regarding reaching the board. We can with A LOT of effort reach the vertical board that appears to be holding in the insulation. The slope of the roof (rise of 5 ft for every 12) is such, that we probably cannot touch it with our hands, but are hoping (if necessary) to be able to reach it with a drill. But even that is going to be a real stretch in parts.
But there is only the one area where we can even see the board that is laying flat over the soffit, and we definitely cannot touch it from inside the attic. I don't know if this board is just kind of lying in there, or if it was a structural member of the original overhang. The original blue prints from 1954 (yes we have those) call for a wood fascia and cornice, but now that is at least covered with aluminum (you saw the aluminum soffit vents). Don't know exactly when it was covered up, but a picture from 2000 shows what looks to be the same aluminum soffit, even though we were told that the roof was redone about 7 years ago. So, the soffit/fascia probably wasn't redone at that time.

First of all lets deal with the ventilation.
You write that the home has worked perfectly for 55 years, (or so it would appear)
The purpose of roof ventilation, it basically to remove any water vapour that escapes from the home into the roof, before it condenses and starts wood rot.
Some find roof ventilation helps reduce heat gain during the summer (but, decent insulation does a better and cheaper job.)
If you have extractor fans in the bathroom and kitchen and there is enough secondary ventilation from windows and doors, then water vapour will not build up and will not be a problem.
Therefore, save your time, effort and money.
The insulation you have is a waste of time.
It should be replace with a closed cell insulation, polystyrene is cheap, easy to fit. It is both wind proof and water proof.
Sheets of polystyrene cut to size with a knife and fitted between the joists, will stop the passing wind from pulling the heat from your home and will make it so much more comfortable.

Perry,
I am confused about some of the comments you made and your suggestions. You say:
"The insulation you have is a waste of time."
What is wrong with blown-in fiberglass and/or rolls? I admit that the insulation that is there is insufficient, but that is why we started this project in the first place.
Why are you suggesting polystyrene? And why does it matter whether it is wind and water-proof? From what I have read this morning, polystyrene is used a) by professional installers (we want to do this ourselves) and b) it is used primarily to spray onto or insulate exterior walls (during construction) or the actual roof. But we were planning on putting insulation on the attic floor (so between the house ceiling and the attic). So, am I missing something?
I can see other applications and scenarios where this polystyrene (either as sheets or blow-in) would be really useful, but I don't understand why we should be using it instead of fiberglass. Is there something wrong with our insulation plan?

Katie, all insulation works by providing a series of holes, usually filled with air (sometimes filled with an inert gas) It is the air (or gas) that provides the insulation the medium is merely a way of trying to trap the air or gas, to stop it from passing its heat on to the next cell.
In the case of polystyrene, it is a mass of tiny balls of air, captured in a fine plastic medium. The plastic is very thin and has a good resistance to the passage of heat. The plastic medium makes the sheet or spray both air tight and water tight.
A ball of air needs to have a size in excess of 16mm approx. 5/8th of an inch before the air inside starts to circulate and transfer heat from one side of a space to the other.
So polystyrene sheet or a similar spray foam has a very good insulation factor that will continue to perform at the same level for the life of the building.
The best available insulation is sprayed foam, perfect for most situations, but expensive.
Next comes polystyrene sheets careful cut to size and pushed in between the joists or rafters as a tight friction fit.
Aim at at least 5 inches of polystyrene, 3 or more between the joists and two below.
In your situation push the polystyrene in between the joists from underneath.
If you measure carefully and cut carefully you will do a perfect job, its your home and you will take that extra bit of time to do a perfect job.

The problem with fibre glass and blown insulation, is that it is impossible to get an almost air tight fit, and the wind blowing over the home pulls the heat through the insulation destroying its advertised insulation properties. Another problem with these types of insulation is that when it gets cold, the damp air moving through the insulation freezes and frozen and damp insulation is an express route out for your expensive heat. In other words they make the problem worse.

When you insulate, you must keep in mind that the wooden joists, then become the weak link. Wood in not as good an insulation as polystyrene.

To make the very best job you must fit tightly butted sheets of 2 inch polystyrene below the joists, to make up for the woods lower insulation properties.

If you do not do this, then over time, because of the woods lower level of insulation, and the fact that it will cause the moisture in the air to condense on the ceiling, you will gradually see a series of grey lines appear, a ghost like image of each joist.

If you do one room at a time, starting with the room that you spend the most time in,
you will quickly feel the benefit, both in the improvement in your comfort zone and in the reduced cost of heating.
Perry

I would pull all soffit material, drill holes (2"x3 each bay) in the rafter blocking, install perforated vinyl soffit venting and attic baffles (with a 2"gap between each) and blow-in cellulose insulation after sealing all holes in ceiling as Bud said. Add continuous ridge venting with baffles. DUROVENT at Lowe's: 48" x 22" Extruded Foam Rafter Vent (http://www.lowes.com/lowes/lkn?action=productDetail&productId=135598-75227-UDV2248&lpage=none) BlockTheHeat.com -Attic Ventilation Problems (http://www.blocktheheat.com/ventproblems.htm) ESB: Research Exposes Attic Ventilation Myth (http://www.oikos.com/esb/30/atticvent.html) Insulation Comparison Chart (http://hes.lbl.gov/hes/makingithappen/no_regrets/insulationcomparison.html) BSI-016: Top Ten Issues in Residential Ventilation Design — (http://www.buildingscience.com/documents/insights/bsi-016-ventilation-top-ten-list/)
Be safe, Gary