Installing baffles in a attic where the insulation has already been installed
#1
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Installing baffles in a attic where the insulation has already been installed
I have someone blow in insulation in my attic about 2 years ago. They did not install any baffles. What is the recommended way for me to get the baffles in there?
#2
I have someone blow in insulation in my attic about 2 years ago. They did not install any baffles. What is the recommended way for me to get the baffles in there?
You do have a continuous soffit vent, right? And a ridge vent?
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Yes, I would like to install the baffles for proper venting. I do have a continuous soffit vent but not sure about the ridge vents. I will have to check when I get home.
After the insulation was blown in the contractor nailed down plywood over the joists so that we could use the attic for storage. I am afraid that the soffit vents are blocked by the insulation. If I shove a baffle down the there wouldn't I be just compacting the insulation more?
As a side note-I have a whole house and attic fan in the attic that vent outside. The temperature in the attic seams to be almost the same temperature as the outside. Am I being worried for nothing?
After the insulation was blown in the contractor nailed down plywood over the joists so that we could use the attic for storage. I am afraid that the soffit vents are blocked by the insulation. If I shove a baffle down the there wouldn't I be just compacting the insulation more?
As a side note-I have a whole house and attic fan in the attic that vent outside. The temperature in the attic seams to be almost the same temperature as the outside. Am I being worried for nothing?
#6
I am afraid that the soffit vents are blocked by the insulation. If I shove a baffle down the there wouldn't I be just compacting the insulation more?
As a side note-I have a whole house and attic fan in the attic that vent outside. The temperature in the attic seams to be almost the same temperature as the outside. Am I being worried for nothing?
The purpose of attic ventilation is not to lower or otherwise control the temperature in your attic. It's to remove moisture and keep the insulation dry and effective. Heat, up to a very high level, just drives the ventilation system.
The most effective and efficient ventilation system for most roofs combines continuous soffit intake vents with a ridge vent for the exhaust.
#7
I have a whole house and attic fan in the attic that vent outside.
@Nash--I've never heard that an attic fan (roof or gable mounted) is a waste of energy. I thought the purpose of such a thermostatically-controlled unit was to remove excess heat in the summer so the "heat load" isn't bearing down on your ceiling.
#8
I've never heard that an attic fan (roof or gable mounted) is a waste of energy. I thought the purpose of such a thermostatically-controlled unit was to remove excess heat in the summer so the "heat load" isn't bearing down on your ceiling.
#9
Cut to the chase. They dont cool an attic in the summer? I have never had one but was considering one for my cottage where I'm way more concerned about comfort than energy costs.
#10
Cut to the chase. They dont cool an attic in the summer? I have never had one but was considering one for my cottage where I'm way more concerned about comfort than energy costs.
If you feel the cottage could be more comfortable than it is now, then there are probably some effective and efficient improvements you could make. Where is your cottage? What type of roof does it have? What is the existing condition of the insulation and ventilation? How many ceiling fans do you have there and how do you use them? Do you have a whole-house fan in the cottage?
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Hot attic?
Buy a weather station and place the remote sensor in the attic.
Connect to your computer and see the temperature in the attic 24/7.
Compare the temperature outside, with that in the attic with the fan running and not running.
Know exactly what is happening in your attic.
Keep in mind that having a ventilated attic, the running fan is pulling hot air into your home through the floors and walls. When the fan is not running the passing wind creates a low pressure area above the roof and down wind to your home that also pulls hot air into your home.
In winter it pulls in cold air.
Having an over ventilated roof is not a good idea, unless you are positive that all the holes and cracks in your home have been blocked and the air inside your comfort zone cannot be removed.
Connect to your computer and see the temperature in the attic 24/7.
Compare the temperature outside, with that in the attic with the fan running and not running.
Know exactly what is happening in your attic.
Keep in mind that having a ventilated attic, the running fan is pulling hot air into your home through the floors and walls. When the fan is not running the passing wind creates a low pressure area above the roof and down wind to your home that also pulls hot air into your home.
In winter it pulls in cold air.
Having an over ventilated roof is not a good idea, unless you are positive that all the holes and cracks in your home have been blocked and the air inside your comfort zone cannot be removed.
#14
Xsheesh, with all the questions I asked you earlier, I forgot to ask the most important ones! Do you use the cottage year-round or just in the summer? Are you interested in conserving heat or just in the most efficient and effective way to keep it cool in hot weather?
#15
Buy a weather station and place the remote sensor in the attic.
Connect to your computer and see the temperature in the attic 24/7.
Compare the temperature outside, with that in the attic with the fan running and not running.
Know exactly what is happening in your attic.
Connect to your computer and see the temperature in the attic 24/7.
Compare the temperature outside, with that in the attic with the fan running and not running.
Know exactly what is happening in your attic.
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The right amount of ventilation!
The problem is....that it is impossible to discover the right amount of ventilation.
When you have a hole, or a number of holes. You are entirely at the mercy of the wind. This relates to how exposed you are to the weather, how high the roof is, the general geography of the area. One day there is no wind, the next it may be blowing a gale...your ventilation will vary depending on the force of the wind and its direction.
Wind wash in attics is a real problem, pulling heat from a home or delivering more heat than you want.
A hole, or holes that may work satisfactory when a building is surrounded by other buildings, trees, hills.....will not work satisfactorily in an exposed location.
The only way to judge if the ventilation system is working is, are you happy with the amount of money you are paying for your heating and cooling.
If you are happy fine. If you think your bills could be lower....then you need the facts.
When you have a hole, or a number of holes. You are entirely at the mercy of the wind. This relates to how exposed you are to the weather, how high the roof is, the general geography of the area. One day there is no wind, the next it may be blowing a gale...your ventilation will vary depending on the force of the wind and its direction.
Wind wash in attics is a real problem, pulling heat from a home or delivering more heat than you want.
A hole, or holes that may work satisfactory when a building is surrounded by other buildings, trees, hills.....will not work satisfactorily in an exposed location.
The only way to judge if the ventilation system is working is, are you happy with the amount of money you are paying for your heating and cooling.
If you are happy fine. If you think your bills could be lower....then you need the facts.
#17
The problem is....that it is impossible to discover the right amount of ventilation.
Calculate Proper Attic Ventilation In 5 Easy Steps
Wind wash in attics is a real problem, pulling heat from a home or delivering more heat than you want.
Last edited by Nashkat1; 03-11-13 at 03:30 PM.
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Roof ventilation
As I wrote earlier, the fit all solution offered, does not allow for the geography of the area or the style of house.
You may well agree that most people are not aware what happens in their attic and have no idea how much over ventilation is costing them in comfort, noise and heating and cooling bills.
You may well agree that most people are not aware what happens in their attic and have no idea how much over ventilation is costing them in comfort, noise and heating and cooling bills.
#19
I stepped back from the discussion because I didn't want to hijack the thread...but it looks like that's happened anyways.
For my cottage at one time there was no ceiling, judging by the age of the materials. Pretty common up there in seasonal cottages and especially in log cabins. Then insulation was stapled up in the rafters to keep it cooler in the summer & warmer during the 2 weeks of deer hunting. THEN a ceiling was added by notching 2x4 joists to fit over the top of the log walls, and another layer of foil-faced batts was dropped into the bays and covered by 1/4" paneling (ceiling) to hold it up and look somewhat acceptable for the lower expectations of the 1960's.
So that's what I have now--an unventilated formerly-conditioned attic now closed off from the conditioning. Not exactly what you find in the textbooks. Heating costs aren't a big concern because I plan to only use the place 2-3 weekends per winter. It's on a lake so I don't think it will ever get uncomfortable in the summer (great breezes there). AC will never be installed here.
Bottom line--I don't know what, if anything, to do. My old shingle roof hasn't suffered from the lack of ventilation. There's no moisture or water issues. Should I leave it alone?
My previous cottage (just a block away) had no insulation at all and my annual gas bill came to about $300--and most of that was a flat-rate monthly "gas availability" charge, not actual gas consumed.
For my cottage at one time there was no ceiling, judging by the age of the materials. Pretty common up there in seasonal cottages and especially in log cabins. Then insulation was stapled up in the rafters to keep it cooler in the summer & warmer during the 2 weeks of deer hunting. THEN a ceiling was added by notching 2x4 joists to fit over the top of the log walls, and another layer of foil-faced batts was dropped into the bays and covered by 1/4" paneling (ceiling) to hold it up and look somewhat acceptable for the lower expectations of the 1960's.
So that's what I have now--an unventilated formerly-conditioned attic now closed off from the conditioning. Not exactly what you find in the textbooks. Heating costs aren't a big concern because I plan to only use the place 2-3 weekends per winter. It's on a lake so I don't think it will ever get uncomfortable in the summer (great breezes there). AC will never be installed here.
Bottom line--I don't know what, if anything, to do. My old shingle roof hasn't suffered from the lack of ventilation. There's no moisture or water issues. Should I leave it alone?
My previous cottage (just a block away) had no insulation at all and my annual gas bill came to about $300--and most of that was a flat-rate monthly "gas availability" charge, not actual gas consumed.
#20
I stepped back from the discussion because I didn't want to hijack the thread...but it looks like that's happened anyways.
I did see where I addressed one question for you to another member But you've answered it anyway, so that's OK. (It was the one about the seasonal use of your cottage.)
So that's what I have now--an unventilated formerly-conditioned attic now closed off from the conditioning. Not exactly what you find in the textbooks. Heating costs aren't a big concern because I plan to only use the place 2-3 weekends per winter. It's on a lake so I don't think it will ever get uncomfortable in the summer (great breezes there). AC will never be installed here.
Bottom line--I don't know what, if anything, to do. My old shingle roof hasn't suffered from the lack of ventilation. There's no moisture or water issues. Should I leave it alone?
My previous cottage (just a block away) had no insulation at all and my annual gas bill came to about $300--and most of that was a flat-rate monthly "gas availability" charge, not actual gas consumed.
Bottom line--I don't know what, if anything, to do. My old shingle roof hasn't suffered from the lack of ventilation. There's no moisture or water issues. Should I leave it alone?
My previous cottage (just a block away) had no insulation at all and my annual gas bill came to about $300--and most of that was a flat-rate monthly "gas availability" charge, not actual gas consumed.
Without access to the attic, you can't really judge how much condensation there might be, or what it's doing. But it could be helping mold to grow there. It could be feeding rot in the ceiling joists or other wood. And you wouldn't know that, at least at first.
If it were mine, I would look for a way to inexpensively add some intake at the overhangs, and I would put a ridge vent on for exhaust, and call it good. No powered equipment. That should keep everything dry, and that should help the cottage, and you, hold up longer.
#21
Without access to the attic, you can't really judge how much condensation there might be, or what it's doing. But it could be helping mold to grow there. It could be feeding rot in the ceiling joists or other wood. And you wouldn't know that, at least at first.
The soffits, facia and roof are in decent shape and not at the top of my TO DO list. When I do get to them I certainly will cut in vents but I don't see any reason to rush into that. I'm considering the (slight) possibility I might retire to this place some day so as the work progresses I will be trying to move in the direction of energy efficiency. If I don't retire here, these things can only help sell the place. I just don't want to do something wrong that will require tear-out down the road.
#22
I didn't realize you had access. From your description it sounds like everything is OK so far.
The condensation problems really only become acute if and when we're heating the interior and driving a bunch of vapor into an unheated attic. Then it can condense on the underside of the roof or in the insulation and wreak havoc if there isn't adequate ventilation.
One reason everything seems to be OK so far, I suspect, is that you say you've only heated the place for a few weekends each winter. If you retire there, or if you start spending longer periods in the cottage during heating season, that could change the conditions dramatically. And that's probably soon enough to address the whole insulation and ventilation question, as you suggest.
I don't think "if it ain't broke don't fix it," for now, is likely to lead to tear-out down the road.
The condensation problems really only become acute if and when we're heating the interior and driving a bunch of vapor into an unheated attic. Then it can condense on the underside of the roof or in the insulation and wreak havoc if there isn't adequate ventilation.
One reason everything seems to be OK so far, I suspect, is that you say you've only heated the place for a few weekends each winter. If you retire there, or if you start spending longer periods in the cottage during heating season, that could change the conditions dramatically. And that's probably soon enough to address the whole insulation and ventilation question, as you suggest.
I don't think "if it ain't broke don't fix it," for now, is likely to lead to tear-out down the road.
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Water vapor/condensation.
When your cabin is empty, it will be dry.
We put water vapor into buildings by cooking, washing, breathing, sweating.
As you are only there for a short time, the 14 cubic feet of water vapor you add to the cabin every 24 hours you are there by breathing and the vapor added by cooking and washing will be minimal.
Untreated wood absorbs water vapor without problem, as the year progresses the amount of water vapor in the air is in constant change, the summer sun dries it, your staying there adds a bit. Nothing to worry about.
We put water vapor into buildings by cooking, washing, breathing, sweating.
As you are only there for a short time, the 14 cubic feet of water vapor you add to the cabin every 24 hours you are there by breathing and the vapor added by cooking and washing will be minimal.
Untreated wood absorbs water vapor without problem, as the year progresses the amount of water vapor in the air is in constant change, the summer sun dries it, your staying there adds a bit. Nothing to worry about.