I have a 60-year-old 1,000 SF brick-and-block raised ranch in
northwestern Illinois. About 17 years ago the original drafty wood
windows were replaced with good quality vinyl and caulked well.
Shortly after that a tear-off roof replacement was done, and an attic
fan and roof vents were added, for a total of 10 vents. There are no
eaves/soffits on the house save for one small overhang at the front
entry. The west elevation (front) is gabled with no vents, the other 3
The new shingles curled much earlier than anticipated on the house;
the detached brick garage’s shingles, installed at the same time, are
fine. Due to the lack of intake vents there is a definite
ventilation/moisture issue, and a roofer has suggested a system called
EZ-Flow Eave Vents, supposedly designed for houses like mine. The
brochure for this system is linked below – does anyone have any
comments on the efficacy of this system?
As the gutters are aged and in mild disrepair my thought is to do a
tear-off on the house and gutters, install this EZ-Flow system (run of
116’), a new roof and gutters at the same time. (The garage is fine
but to color match I may add a second layer.)
Additionally, there is a bathroom exhaust fan that is piped and
hanging directly underneath a roof vent nearer the gutter than the
roof ridge. Is it advisable to vent this differently as long as all
this other work is being done? Ditto a kitchen ceiling exhaust fan.
Should I scale back the number of roof vents if I install this EZ-Flow
system, as don’t the intake and exhaust areas need to be balanced? I
realize a good roofer should make recommendations about this but being
a single mom, it helps to be educated in advance.
Thanks for any comments.
Here's the text:
Expert: Stan Skarbek
Subject: eave vents
I like your answer about roof vents. Adding ridge vent to gable vent . I
am in Michigan where we get snow what do you recomend for adding eave
vents to a house with no eave overhange .
If there are no eave overhangs, I recommend that you don't add eave
vents. Even if you're able to install them between the rafters, with no
eaves, the rain and snow will blow into the vents.
What you can do, if you have an open attic (as opposed to cathedral
style ceilings) is to install some eyebrow style attic vents in the
roof, down low, near the edge of the roof. Putting a few of those vents
down low on each side of the house will accomplish the same thing as
regular eave vents. I recommend installing one vent every 10' to 15'
along the bottom edge of the roof.
I hope that helps. Feel free to follow up in the future.
Your roofer with a keyboard,
Thanks. I do currently have 9 pot vents distributed between three
elevations. Two high and two low on both sides of the house and on the
back there's one near the top. Are pots that much less efficient than
eyebrows? I also have a thermostat-controlled exhaust fan smack in the
center of the X made by four of those aforementioned vents. I found
this mentioned in many places:
When attic fans remove more air than is drawn in by soffit vents, the
vacuum created in the attic can draw air from the house rather than
I believe that may be the problem, and while half of those pot vents
were installed low in an attempt to overcome the lack of soffit vents,
I just don't think it's enough, hence my moisture problem. Last winter
was bad and I had ice dams in a few places, one in the vicinity of the
kitchen exhaust fan. Coincidence? Feh.
Between 3 teens showering innumerable times daily in a one-bathroom
house, gas appliances and heat, plus a huge vent-free gas fireplace in
the basement... we produce a ton of moisture. Heck, evaporation from
the bath towels alone is frightening!
I've totally bought into the need-for-ventilation thing -- just not
sure how to best accomplish it in my soffitless home.
Ice dams are caused by poor insulation and/or vapor barrier in the walls
- common in older houses. Warm air gets into the wall cavity and rises up
towards the attic. While the top plates (2 x 4 cross pieces)prevent a
direct connection enough heat gets up close to the tops of the walls and
leaks into the attic at the lowest part of the roof. It melts the snow
and causes ice dams. Since there is only a little heat it can only melt
snow in the winter warm spells. That's why the dams are worse in warmer
Your high low vent pattern is on the right track - add a few more,
especially low ones near the ice dam locations. Naturally snow can block
these vents so you may have to take a snow rake to the areas around them.
In our city, Winnipeg and very cold, many people use heating wires along
the low parts of the roofs to melt ice dams or prevent them from
The shingles curling is a summer over-heating problem which could also be
addressed with more vents strategically placed.
Are the kitchen and bathroom vents through the walls? If so you could add
short (just enough to extend past the eave) extensions so the warm air
isn't near the roof. Use 90 degree elbows pointed downwards to prevent
reverse airflow into the house. The fans have enough power to blow the
air out and down.
Your house moisture problem could be solved by addition of an HRV (Heat
Recovery Ventilator) to the furnace. These have 2 fans and blow outside
air in and inside air out. They recover about 75% to 85% of the heat from
the outgoing air and put it into the incoming air. Since outside air is
dryer than indoor air they dry out a house nicely. Our house is now too
dry if we run the HRV's too much in the winter. The best way to install
them is to draw the air from the wet rooms like the bathroom and kitchen.
The incoming air can just be routed to the return air duct or any of the
other rooms. They come with dehumidistats so you can set the moisture
level. Ours can also be set for continous Min, continous Max or 20
minutes of every hour.
HRV's are about 150 cfm - 3 times the flow of a small bathroom fan or the
same as a large fan. This is relatively low flow so they run for long
periods of time.
You can check out the specs and efficiencies of most HVAC products at
Section III has the good descriptions of how they work plus all the data
Our house was new construction so we could install ducts from the
bathrooms and kitchen but that is too expensive for retrofit. I think
HRV's can be installed in attics but I am not sure if that applies to
very cold winter areas. Check with a good HVAC company. If they can work
in the attic and duct through the ceilings it may work at reasonable cost
- over $1500, maybe $2,000 but that is a wild guess. Units cost around
$850 to $1,000 but labor is tough to guess at. Needs electrical wiring,
etc. Wouldn't hurt to get a quote.
HRV's can be easily installed in basements near the furnace. Use 2 pipes
through walls. This method just gets at the whole house air. Trouble with
that method is that you don't get the wettest air from the wet rooms
unless you can somehow duct to them. Don't know if it would be adquate to
just dry out the house as a unit, might be. If the basement ceiling is
open it may be possible to intercept ducts to or from the bathroom to
focus on that location.
Another option that should be cheaper is a dehumidifier. If you have
space you could put one in the bathroom. The cheapest ones need you to
empty the tank manually. The better ones have a small pump but you need
to connect the drain tube to the plumbing. Most costly would be a ducted
dehumidifier somewhere, perhaps basement. Run a duct through bathroom
floor to get the wet air. Best is to route exhaust upstairs somewhere but
you could just let it exhaust into basement. That would force basement
air with it's odors upstairs. Would dry out basement nicely. Install
drain to floor drain or plumbing pipe.
Through the celing to nearest attic pot vents. Thinking about adding
dedicated roof vents for both of these and insulating the runs.
Interesting. Looks to be out of my short-term budget at the moment but
at least I've a dropped ceiling in the basement that provides good
access to the ductwork. I have a sheet metal buddy that might be able
to help with the labor.
Do have a pump model, however it's in the shop right now for a
warranty repair to its fancy schmancy computer panel. It does help but
the heat it generates in the summer makes me shove it in a back corner
of the laundry room.
Thanks for the thoughtful reply. I'm on information overload at the
moment -- so much to think about -- but much better prepared for the
roofing estimators due out over the next few days. I often get
patronized or condescended to by contractors as being a dumb blonde so
getting some facts in hand first keeps me from wasting time with the
jerk specimens. ;P
On Jul 23, 8:28 pm, firstname.lastname@example.org wrote:
The product to go next to the fascia looks interesting. From the
brochure, I can't picture exactly how it gets installed on existing
construction to get air access into the attic. Seems you would have
to cut a tricky slot somehow.
But some type of continuous soffit vent system combines with a high
vent, typically ridge, is recognized as the best solution. Also, if
you go this way, make sure that attic insulation is not blocking the
vents. They have plastic baffles that are like chutes that you can
staple to the underside of the roofing, where the rafters meet the
walls to keep it open.
On Thu, 24 Jul 2008 05:39:39 -0700 (PDT), email@example.com wrote:
You're exactly right. A thin horizontal cut of is made at the top of
the fascia board. I was provided with references and after speaking
with two very satisfied customers decided to go with this system.
This is precisely what was recommended; install the EZ-Flow vent
around the entire perimeter, eliminate all the pot vents and exhaust
fan, and install a ridge vent. Also going to directly exhuast both the
bath and kitchen fans with damper vents in the roof. I was conflicted
about removing the fan but he said due to the small size of my roof
area there's no good placement spot for the fan that wouldn't risk
short-circuiting the low->high ventilation.
Last thing I'll do is reinsulate the attic and then I should be good
Thanks for all the help.
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