Has anyone ever done a retrofit on a house to superinsulate it? If so what and how did you do it? I keep looking at my gas bills and whats going on in the world. My house is pretty drafty so I have been slowly plugging the air leaks, but she keeps talking about putting an auxilary heater in my daughters room. (it can get really cold in there, the HVAC subs that built the house ran a doozy of a heat duct, out the cantilever over the front porch) I keep reading about SI houses and they really sound like the way to go so I wonder if anyone has done it yet. Thanks.
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Super insulating an old house to the standard that basic human activity in the house provides all the heating... is likely not going to happen in most houses. (that is what superinsulation means to me anyway).
There are some places in an old house that are contraindicated to insulate - such as the inside of a rubble(fieldstone) foundation below grade more than a foot or two. There are other places that are expensive -walls.
Start with the attic and the basement. They give you the most bang for your buck. Airseal first - then insulate (i learned that one in this forum, forgot who said it, boy is it true).
When you airseal watch the humidity levels in your house carefully (learned that one the hard way)
How old is your house? How is it built? Where is it built?
My house is basic stick built house, poured concrete foundation built in 1990, vinyl siding. The garage is half of the basement. It has a gas forced hot air furnace, gas HWH, gas stove. Two stories, unfinished basement and a walk up attic. Last winter I sealed the knee wall in the attic and put some of the 3M film on three of the worst leaking windows. This winter I did those same three and three others. It makes a difference, I just can't quantify it. I was feeling around the sill two weeks ago(which is already insulated but I don't think sealed) and it was quite cold. I live in Easton, Pennsylvania, about an hour north of Philadelphia, maybe one or two miles from the Delaware river. The basement is not finished. Are you recommending that I finish the basement and insulate it then or just make sure the sill plate is sealed and there is good insulation in the rim joist area? Thanks.
I think how much of the basement you finish and insulate depends on your budget and your foundation.The biggest bang for your buck is to do the sill plate (which is really cheap and accounts for a lot of air leakage). The next step would be going down to about a foot or two below grade. That combination will take care of about 70% of your basement heat loss (according to http://www.buildingscience.com).If your foundation is NOT fieldstone/rubble then feel free to go all the way to the bottom. Since you say your foundation is a nice modern poured conrete structure you can insulate that all the way.Last year I didn't know what any of this stuff meant.
how do you insulate the sill plate on a house already built?? I am facing the same kind of situation. do i use foam?? not sure how that works or waht the best way to go about that is. would appriciate all replys.
Also, can i insulate around the windows from the outside?? they are drywalled in on the inside, i notice a lot of airmovment around some of them.. i tried the plastic but that never really sticks well, and my two year old dosent help much !!
thanks guys...
Frank
We were the winners, cause we didnt know we could fail....
Waylon...
"I was born in the darkest ignorance, and my spiritual master opened my eyes with the torch of knowledge. I offer my respectful obeisances unto him."
Aciores autem morsus sunt intermissae quam retentae.
(Freedom suppressed and then regained bites with keener fangs than freedom never endangered.)
Cicero, De Officiis
Well, I suppose it depends by what you define as super-insulation. When we gutted our 1872 Mansard, we discovered that none of the walls were insulated (as expected).
We took a hybrid approach to insulating the place, using Corbond (i.e. R6.5/inch) in the old part of the house (true 4" studs), and Icynene in the addition (i.e. R3.7/inch) where we used standard 2x6 studs (i.e. 5.5"). Overall, that's about R20 in all the walls (subtracting for thermal short-corcuiting via the studs and all that). I think the attic has 6-7" of Corbond sprayed into the rafter bays. Should be plenty.
In case you don't want to open up walls, consider Icynene or dense pack cellulose throughout. Get a contractor with a thermal camera to veryify that all stud cavities are filled. According to a friend, even a 5% void can derate the wall insulation by 50% due to thermal short-circuiting... so it's usually best to have open walls to start with, they're easier to fill.
Don't forget the windows... either retrofit quality storms like Harvey Tru-Channels or go with some very expensive new windows. I'd always go the storm window route first, most older windows are made from great wood that can't be had anymore. It's one reason the majority of windows in our home are 130+ years old and still in good shape. With spring bronze and other measures, your old windows can be made quite weathertight.
As for the heat load, that has dropped dramatically. Whereas the former heat plant (a 200kBTU Williamson oil-furnace) barely kept the place warm in the winter, the new heating plant (using RFH emitters) will only need to supply something on the order of 66kBTU on Boston design day. I sized the plant for -15*F conditions, when the house requires about 90kBTU to stay warm.
You simply cannot superinsulate a home without a total gut. Are you willing to do that?
Or would you just settle for a increase in your insulation effectiveness?
One thing I found after carefully examining everything is that a tear down approach was dramatically cheaper and faster and far more efective than the rehab approach..
I did a modified teardown in that I tore down a portion of the house and did that while living in the older half, and now I'm going to tear down the other portion of the house and move into the new portion..
What I kind of planned on was working around the rooms with some remodeling and as each room was done incorporating about 8 more inches of insulation and sealing the electrical boxes and putting in a 6 mil vapor barrier. This would work really well in the kitchen when I remodel and in my family room and dining room, I want to add some custom wall units. I also don't think the rim joist have very much if any insulation in there.
You say the place is drafty.
The low hanging fruit would be to determine the extent and source of your convective losses, and work on that first. This work is going to have the best cost/benefit ratio. The best way is to get someone to come by and do a blower door test. Consider the sealing and insulation of the ductwork next. The rest of what you are proposing may have diminishing returns.
Put another way, you might get 80% of the benefit of your 'superinsulation' target for just 20% of the cost it would take to get there.
For example, expensive things like replacing 15 year old windows generally do not have a good payback period relative to cheap air sealing measures elsewhere.
80% return on the first 20% effort/money sounds pretty good to me given the direction of fuel costs, but some of the windows are really bad. The first winter I used plastic film was when the furnace didn't shut off for three days after we turned it down to 55 for a weekend away. The wind was blowing and the temperature in the dining room didn't get above 62 degrees for a week. When I finally put the 3M film on the two windows it bowed out almost 3". What's the best way to seal/caulk a window on a vinyl sided house? From the inside or the outside? And whats the best way to seal the sill, from the inside or the outside with spray foam or acoustic caulk?
"What's the best way to seal/caulk a window on a vinyl sided house? From the inside or the outside? And whats the best way to seal the sill, from the inside or the outside with spray foam or acoustic caulk?"
Generally, it is best to seal windows on the inside. When it is as bad as you say, the installation was likely done poorly. You could try removing the interior trim, remove fiberglass insulation around frame (if any), and reseal with low expansion foam.
Not sure what you mean by "seal the sill".
Well if you take off the molding around the window and your looking at the stoop at the bottom of the window I guess you would just treat that like you do the sides of the windows.
"Well if you take off the molding around the window and your looking at the stoop at the bottom of the window I guess you would just treat that like you do the sides of the windows."
that's right. Depending upon how it was installed, you may be able to leave the windowsill in place.
On another note, on another post, Rich from Columbus saw a picture of my basement and asked if I was going to insulate the basement wall to below the frostline, my thought was why stop at the frost line but go all the way to the floor? Also do you recommend doing both the outside and inside or just the inside (since it's easier). When you do the outside what do you cover that insulation with, stucco? Real or synthetic?
Well, you realize then the loss of space? What I would do is pull all the insulation from the walls. Have foam sprayed in and then seal up the walls. If you do that not only would drafts stop completely you could add 2 inches to the studs and have 6 inches of foam insulation without the extreme loss of space a double wall system would have..
Jon,
We have 2800 sq', full basement plus attic, my last bill this year was $256.53, last year or the year before it was pushing 300 one month. I totalled the gas bill for four months last year and it was over $900.00, total bill for the year was $1150 or $1200. I'm not to concerned with loss of space, except in one or two areas, mainly the main entrance, where the stair landing is right by the front door. My wife is concerned in one bedroom which is pretty narrow, only 7' wide. I could do a mix, depending on cost and stuff. What's the R value of the spray in foam?
Depends on the foam. Closed-cell polyurethane like Corbond can approach R6.5/inch. However, it cannot be retrofit into extant walls easily - practically no installer will do it. Icynene and other open-cell foams are usually around R3.7/inch, which is close to fiberglass. Icynene is usually cheaper than Corbond R for R in an open-cavity situation.Corbond is so efficient that there is no need to thicken the walls in most homes. Even 3.5 inches will result in something like R15 walls (once you account for thermal shortcircuiting across the studs). So corbond will preserve lots of interior space and may save you time. It also acts as a Vapor barrier because it's very impermeable. Icynene is not nearly as impermeable and requires thicker walls for the same R-value insulation. We used it in the addition, which we built with 2x6 studs. When it's that thick, our insulation company tells me that it's virtually impermeable and that no vapor barrier will be required. Time will tell.Here is the kicker though: How often do you want the installers to come back? There is a fair amount of setup involved in getting the chemicals up to temp, etc. so calling the pros on a room by room basis is probably out of the question (depends on the contractor, I suppose). Our guys took about 1 hour to get ready in the morning, not the most efficient crew by any stretch of the imagination.If you want to DIY it, you could consider alternate routes like Handi-Foam, which allow you to self-apply the stuff from smaller packages. Not likely to be cheap either, but for a room-by-room approach, it may be the best option.
256 smackers aint that bad, now!
No need to get nuts superinsulating your house, like Jon said.
What you are proposing could cost north of 10 grand easy.
You have to look at payback here, not just what would be the "best" scenario; and you have to consider how long you will be in the house.
As was already mentioned, focus on airsealing all your leaks first. That should knock 20 percent minimum off your bill.
Then use an insulation that fits into your payback and projected length of stay in the home.
Steve,
How bad are your heating bills, and how big is the house? It costs me $130/month to heat my renovated 2400sq/ft 1920's cape when it's minus 15F with minus 60F wind chills. No super insulating, just to R22, foamboard and fiberglass in the walls and roof. BTW, we keep the place at 73F.
WSJ
Steve,
Where are you, Forks Township, Palmer ?
I am in Wilson with a 2000 sf 1920's all brick home with all gas like you and I wish I had your gas bills. You are not paying that much for gas. Your problem is that the house is drafty which is the fault of your builder. You probably have cheesy windows with vinyl siding and fiberglass insulation in your walls and ceilings
Superinsulating suits new construction or total guts to the framing. I don't think you want a total gut. homer is right. the return on your superinsulating investment will never ever pay off.
If you want to spend lots of money to make the house more comfortable that is one thing. If you think you are going to save much on a $1000 a year heating bill, no way.
You probably would like new windows right ? Let's say you replace all 28 windows in your house at a cost of $1000 per window installed. That's $28,000 total cost. Your gas savings might be $100 per year. See what I mean ?
The same thing is true of the interior insulating. If you really wanted to reinsulate the house then stripping the drywall off the outside walls and spray foaming is the best way to go as mentioned. Pretty intrusive for your daughter though.
An alternative would be dens pak cells or fiberglass. The problem is the batts already in the walls. They need to come out. We have tried pumping more loose insul into walls like this and it doesn't work.
Stopping air movement is the key more than the big R value number. Fiberglass batts are the worst at stopping air movement. Vinyl siding doesn't do anything either.
If you are really into this, you could consider starting in one room, removing base moulding from the outside wall and horizontally cutting the drywall at about 2' up off the floor on the outside walls. Then pull the fiberglass batts out of the walls, and put new drywall on the removed area. Don't spackle it. We have a guy locally who will come in and pack loose fiberglass into the walls by drilling two 2" holes in the walls in each stud bay. I suppose you could rent a cellulose blower and do it yourself (maybe at Leiser's rentals ?) with blown cellulose which is better but dustier (major) for a finished home. This could be done on a room by room basis. The spackling is then done and you must repaint. You can also remove window trim and foam the windows to stop the air.
Next stop is the attic where you need to add some blown in insul to what is there. You lose the most heat through the top.
It's a lot of work but it beats making your house smaller by 300 sq ft.
carpenter in transition
Edited 3/11/2005 8:44 am ET by TIM_KLINE
Yes, I llive in the development just south of Bradens. When you drive up Sullivan trail and cross Newlins road look NE and my house sticks out into the cornfield.
I did the CBA on the windows a couple of years ago and that's really a no brainer, however, every time I see the plastic billow out my mind starts thinking, how wastefull is this?
I don't really think a 300 sq ft reduction is that high a price to pay, the person I really need to convince is my wife. Why is the blown in insulation so much better than batts, or is it how everything is installed?
I always intended to do it one or two rooms at a time, never a full blown gutting. I would be out of the house and in the garage before I knew what hit me!
As far as payback is concerned I don't plan on moving, unless I can't walk up stairs, and since I'm only 42 I think I have a while here. No real worries about job relocation.
Question: If I go chasing air in the attic and end up pulling a fiberglass batt out of a cavity to plug an air hole won't I be destroying the vapor barrier created by the kraft facing?
Question: If I go chasing air in the attic and end up pulling a fiberglass batt out of a cavity to plug an air hole won't I be destroying the vapor barrier created by the kraft facing?
I don't quite understand the chasing air in the attic, but...
yes you will be destroying the vapor barrier. more than likely, it isn't doing much anyway because it wasn't installed properly. batts are rarely installed properly and as a result, a lot of air movement occurs around the batts.
the blown in is packed tightly and stops all air movement. which is why you don't need to worry about losing that kraft paper. if you don't have air movement to the outside you really are going to have minimal vapor transmission as well. the paint film on your walls is probably doing more than your kraft paper on your insulation as a vapor barrier.
I don't really think a 300 sq ft reduction is that high a price to pay, the person I really need to convince is my wife.
It may not sound like that much, but you should mock it up with some sheets or cardboard in one of the smaller rooms. You'll be surprised. Were you planning on rewiring the house and moving all of the forced air supplies while you are adding these extra walls ? When you add a new wall inside your existing exterior wall, what are you going to do with the electrical outlets ? You can't just add a piece of wire to extend it because you can't bury the old boxes. No inaccessible splices are allowed. And the air supplies which come up in your outside walls ? Now they will all have to be extended.
Retrimming all the windows with deep jambs....
New exterior walls that run into existing closet door trim and jambs.....
You better start heading to the garage now !
carpenter in transition
Chasing air means trying to plug all the air leaks. Something I read in either another post on here or in one of the FHB articles I have been reading.So it looks like I have been thinking along the same lines as you, it does sound quite daunting. I realized about the wiring and the heat ducts but would you believe that all but two ducts run up the middle of the house? those two feed the attic. I checked with mirrors and a flashlight and all the rest of the ducts come from the middle. One bedroom duct has yet to be figured out, I am pretty sure that it makes a wild turn and goes out over my porch. You wouldn't believe some of the stuff that this builder did. I kind of like the idea of window seats, as do at least two of my kids. They love to read and there's not much better than a window seat to read a good book. Yea, my wife isn't quite convinced yet but I keep hitting her with the costs and I am kind of fanatical about recycling and conservation. My six year olds room is really cold and my wife wants to put a space heater in it. Which is ok for the short run, but heating fuel is just going to keep climbing! I have some pretty strong opinions about all the politics and all, but this is not the forum for it.
No disrespect, but you're trying to polish a turd. <grin>
Sounds like you should just build a new superinsulated house.
That is, if you think that the ideas thrown your way so far aren't viable solutions,
and that the only way for you to really save money is to build Mooney walls inside
your existing house. Check this out.
I gutted my 2nd floor master bedroom down to the framing recently. Its in an attached ell and has its own roof and is super drafty to say the least. It is an unheated space right now. If I leave the plastic zipper door up that is closing off the room up on a 20 degree day, the house temp will drop very quickly, and you can actually feel the breeze of warm house air rushing into the cold room....
Zip up the plastic, and VOILA, no more breeze, house gets warmed right back up.
Now what do you think the R value of my plastic door is?
My point is that you dont need to go to extremes to save some cash.
I don't feel dissed at all! I've always had a propensity to tilt at windmills. I also like old cars from the 60's, old planes, and old motorcycles. Just about the only young thing I like are 18 year old women (grin). The point about drafty homes really is being driven home. I just need to seal all my drafts and see where that leads me. The "fun" part is finding all the leaks!
One thing I didn't see mentioned (unless I overlooked it) was carbon monoxide poisioning. You mentioned your gas bill so I'm assuming your not all elec. Get an energy audit from an energy specialist with a blower door. If you have a family of 4 or less you shouldn't go over 1500 cfm if you have any combustion appliances. If you do you might not wake up one morning.
Currently in most parts of Texas you can get an audit for free. Contact you loacal energy provider, they may offer this service as they do in Texas.
I have a CO monitor but that's a really good point, I'll make sure I check that out. Thanks
but I keep hitting her with the costs
What costs ?
Everything we talked about ?
NEW:
Carpet
Drywall
Taping and Finishing
Framing
Insulation
Rewiring the house
Ductwork retrofit
Trimming windows
Base Moldings
Painting trim
Painting walls and ceiling
Dumpsters
Cleanup ( to satisfy a woman with children)
All this to save a couple hundred bucks a year on gas ? I can see your wife's post in the Tavern already: "Divorce Attorney Needed".
You're on the right track with stopping air movement. Start with bringing attic insul up to at least R-38 with blown in cellulose. Get yourself a good foam gun and start foaming windows and around electrical oulets.
forget the idea of bulding new wal.carpenter in transition
Yea, I think you hit just about all of them, except for the vacation and maybe some new clothes or a new car, to calm her down and all. Oh, I almost forgot, my time not being available to her for all the other incidentals that a very understanding wife might deserve for putting up with my particular brand of insanity!