Okay, this is what I have. It is a cape cod with 4 doghouse (?) dormers and a large shed dormer. There are crawl spaces in the upstairs rooms with doors. The attic itself is just a crawl space although I have never been up there.
I have huge ice dams and I am hoping the cause is due to lack of insulation. I plan on having an insulation company out soon and I really want it done thoroughly.
I just want to verify that I have understood what I have read on this board and my plan is the correct one.
The cubby holes in the bedroom should be insulated on the floors and inside walls. The attic floor should be insulated and not the roof?
From what I read, forget the FG and use spray foam and some kind of rigid board?
I am sure there is no insulation in the walls either. I am planning in the future to have the aluminum siding removed and possibly whatever is under there too. Can I wait to have the walls done later and with what?
I am also having an upstairs bath, that has two outside walls, gutted. What type of insulation should be used in these walls? They will have a shower and a tube along them.
Replies
Where exactly are the ice dams? steep sections and or shed dormer? do you have soffits if so how deep?
The ice dams start at the gutter and go up the roof about 2 feet....actually to the bottom of the doghouses. I suppose I could prevent the icedams by using the heated cable but don't they signify an insulation problem?
The ice dams are on the steep areas. There are soffits that are about 4 inches? deep>
Edited 2/20/2007 3:26 pm ET by AcCable
It sounds like you have a cape cod with a finished upper level with dog house style dormers with windows installed in each. The rooms are centered and knee walls make up the sides of these rooms with the rafters making up the ceiling in these rooms. You have access to the other side of those knee walls where you can see some insulation in the ceiling below. Hopfully you see insulation in the knee walls themseves and in the rafters/ ceiling above your rooms combined with rafter mate or some type of gap to allow air to pass from your access area to the ridge for air flow. The rafter mate should also be in the soffit to keep seperation from your ceiling insulation below. However there should be no insulation in the rafters from the point of the knee wall to the soffit. Use fiberglass in the walls unless you have the money for the spray on.
Edited 2/20/2007 3:22 pm ET by AllTrade
Edited 2/20/2007 3:27 pm ET by AllTrade
Edited 2/20/2007 3:29 pm ET by AllTrade
You described the upstairs perfectly except the part where I am supposed to be seeing insulation.
I am using what you wrote as the guidline to what I should have installed. If the walls are opened in the bathroom I do plan on having spray on whenever walls are opened up and need insulating.
A question arises.....what and how should the slanted walls (rafters) be insulated. How could a rafter mate be installed without tearing open all the (plaster) covering. Should I forget about trying to vent the soffits to the ridge vent and just drill holes and pump in foam? By saying that, I mean have some one else do it. :)
Just trying to do the best and most effective way with what I have to work with.
Thanks for your replies.
I assume they are 2x6 rafters? If so you don't have much there to begin with so pushing rafter mate or something to create a channel would compress or tear what is there. I also assume the ceiling has a flat spot at the top about 2' to 4' wide or does it come to a peak? If it does have a flat spot then hopefully they only insulated that flat spot and not up the pitch to the peak. That means you have a triangle area across the whole ridge of space that can breath at the top. So I would not remove everything just to get best case senerio in a 8' section of rafter bay .
Now if it it is not insulated and you decide to "blow in" then with some "love of the game" you could rig some baffles up in there.
Edited 2/20/2007 10:37 pm ET by AllTrade
Yes, I do have a flat spot of about 6-8 feet across. Haven't been in the attic as yet to see what, if any, insulation is up there. My original plan was to have the floor of the attic insulated but then didn't know what to do with the walls.
Don't mean to waste your time and I really appreciate your insight. Guess I just need to get up there to see if I can get any additional information. At this time, I am assuming there isn't any insulation at all in the walls. That is probably not correct but the first floor walls that were opened up did not have any, or in the case of the added on room, had very little insulation. The house was built in 1959 and an addition and large shed dormer added at the opposite end of the house in the 70's.
I realize the best way to insulate may be practical in only new construction or entail tearing out all the upstairs walls to do properly. I certainly do not want to do that but on windy days the upstairs has a definite breeze.
Question is, is something better than nothing or will the results be minimal unless drastic measures are taken?
Just reread your post. Your "love of the game" comment sounds interesting. A challenge to actually try to install the baffles. Would you forsee this being worth the expense and aggravation?
Depends on where you are. Check out Building Science -- http://www.buildingscience.com
Thanks for the link. Will definitely check it out.
It will really help if you can post us some pictures or sketches, as that will help us all identify the various features being named--not all regions call the same things by the same names.
The suggestion to check out the buildingscience site is one I'll second, they have some very good info.
Now, in a remodeling situation, it can be helpful to complete any utility changes, like wiring or plumbing, before insulating. That, can also depend on which insulation and the "how" of the insulation, too.
From your description, it sounds like you do not have a traditional attic, as in a space above the living area not used as habitable space. That sort of space has two schools of thought on insulating. One would have you insulate the "floor" of the "crawlspace" attic areas, andthen turn the insulation up the kneewalls and on into the exterior walls above the roof lines. The other would have you insulate the exterior walls, then up against the roof decks and then back into exterior walls.
Since you probably do not have ductwork or hvac in your "attic" spaces, the argument can be made either way. So, how to pick? Well, you could check your local AHJ (Authority Having Jurisdiction, usually the Building Dept, or Planning Dept at the City or County). It may be that having ventilated roofs is mandated in your area. If so, that kind of settles the argument, unless you are keen to get a variance, which can be easy or it can be hard.
To me, insulating the ceiling plane is easy, but tends to be difficult to do without gaps, spaces, and all of the other bugaboos that 'compromise' insulation. Not that it can't be done, just that it can be difficult to do well.
Wish I could make a drawing that would make sense but I'm sure is would come out as nonsense.
By your description of the two accepted methods, you seem to have the right picture. Now could the same product be used for both methods? Is the spray on foam overkill? I can't imagine FG could seal all the nooks and crannies but don't understand how they would be able to insulate behind the slanted walls that actually make up the roof line. The actual peak would be okay but not behind the slanted walls. I am leaning towards the spray....of course, that may change when I see the cost. I have heard it is much more expensive.
I want to do this as thoroughly as possible.
but don't understand how they would be able to insulate behind the slanted walls that actually make up the roof line
Well, what you could look into is blown-in cellulose. That just requires a hole about 1-1/2" around in each "bay" created by the framing.
Blown-in cellulose will hot give you the vapor-sealing effect of spray-in closed cell foam, but you also do not have to strip the walls to bare studs (unless that's needed for some other reason). That puts you in the position of having to decide how, and where, to put your VB (vapor barrier) in. That has some troublesome choices, many of which are much easier with walls stripped to bare studs (you notice a catch-22, chicken-egg-chicken thing going on?<G>)
But, you are definitely correct, FG winds up being useless in these applications all to often, and that before contending with the effects of hunidity on FG--but that's a separate rant.Occupational hazard of my occupation not being around (sorry Bubba)
This does sound like a catch-22. Now the vapor barrier thing has me concerned.
Am I wrong in assuming there is no insulation in the slanted walls or would there be a tell tale sign indicating this and a lack of a vapor barrier. Would a vapor barrier have been installed at the time the house was built without accompanying insulation?
Other than the room being very cold and drafty , there isn't much else to say. The room has 4 dormers with window and another window at the gable end. Come to think about it, one cold day the electric heater was on full blast and the gable end wall was weeping. It only happened one time. Don't know if that means anything.
Am I wrong in assuming there is no insulation in the slanted walls or would there be a tell tale sign indicating this and a lack of a vapor barrier. Would a vapor barrier have been installed at the time the house was built without accompanying insulation?
As a guess, no insulation = no VB.
Except, if the house is of a certain age, it will have asphalt-impregnated felt paper on it's outside. Depending upon the era the builder's felt is from it might be a quite good VB. Or not. Note that cold and drafts may be from loose window parts, rather than leaky (to vapor & breezes) walls. Now, that last is "on average," too.
Generally, "we" want the VB on the "warm" side of the wall construction, this prevents water vapor from being carried into the wall structure and/or insulation, where it could condense into liquid form and generally be very impolite. Preventing that, is one of the keys to the building science construction recommendations.
Now, in colder climes, there's the additional desire to keep cold air from infiltrating the wall structure. That has people applying a wind-proof house wrap on the outside of the house, and a VB on the inside. Some people then confuse the materials, and create two VB, which is almost never a good situation.
You are in a remodel situation, and that's always a compromise of one sort or another. Which means spending quite a lot of time looking for the hardest place to perform the hardest task, and trying to figure out what the best compromise will be.Occupational hazard of my occupation not being around (sorry Bubba)
I had the same situation.
Icynene foam. Airsealed the entire attic from ridge to soffits. No venting whatsoever.
Ice damming is gone.
TP
I understand what you are saying but if there isn't a vent, how is the hot air build up vented out in the summer?
Your attic becomes "conditioned space" just like the floor below it.
Icynene has some good information about unvented attics on their website. And, no, I'm not an employee of Icynene.Toolpig (a.k.a. The man formerly known as "Toolfreak" and "Toolfanatic")
I'm with Toolpig on the use of soft foam insulation in your situation. Be sure the manufacturer of the foam has an ICC (code)compliant product. It sounds like Icynene has this compliance, Sealection500 by Demilec does, I'm not sure about others.The insulation of the entire roof deck w/o an air space will be more efficient in your situation due to the space limitations. Garett
Edited 3/3/2007 9:44 am ET by Grott