foam boards on interior?

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Old 11-21-03, 01:25 PM
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foam boards on interior?

Hi all - I'm working on an old home with asbestos siding (in good shape) and plater & lathe walls. No insulation at all. Rooms are fair size and since I don't want to re-side the house I was thinking of installing 2x4's and using rigid insulation then covering with sheetrock any comments or suggestions will be appreciated

BTW - will be blowing in insulation in attic, insulating cellar "ceiling" with batts and have rulled out blown in in walls - Estimate was just about 1/2 of what I paid for the house!
 
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Old 11-21-03, 01:56 PM
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Problem with sheet foam insulation is that by itself, it doesn't give you much R-value. I consider blowiing the walls yourself. I buy insulation from a local lumber and get free rental on the blower. My $.02 worth.
 
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Old 11-25-03, 07:43 AM
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your .02 / & improperly installed insul.

I don't think that blown in insulation is a viable option.
The house is plank, plaster and lathe. I removed a portion of the wall to install an addition and can tell you that there is less then an inch between planks and lathe. Asbestos siding attached directly to planks. The contractor that gave the estimate to blow in checked neither the attic nor basement to determine the available space (actually seemed to be a salesman and not a contractor).

I'm planning on studding the exterior walls, installing 4" insulation (r-13 I believe) and putting up new sheetrock.

Also the insulation in attic was put in upside down (paper vapor barrier faces up rather then towards the heated area) Should I pull it out and reinstall it? I was planning on blowing in addtional over the top.

Also the insulation in attic was put in upside down (paper vapor barrier faces up rather then towards the heated area) Should I pull it out and reinstall it? I was planning on blowing in addtional over the top.
 
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Old 11-25-03, 08:44 AM
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You don't have much space in the walls. It is quite unusual to see so little space. Good idea to have investigated your particular circumstance.

Studding the exterior walls will be a sensible option for insulation as well as any changes you might want to make to wiring.

If the vapor barrier is reversed in the attic, turning it to the proper position is important. Adding insulation over it otherwise might allow moisture condensation inside the total insulation layer and spoil not only the insulation, but also the ceiling beneath.

The expense for labor frequently drives DIY for procedures that are tedious and time-consuming, but not technically difficult. The labor cost to retro-fit insulation in my house has helped me decide to DIY.

Hope this helps.
 
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Old 11-25-03, 09:33 AM
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foam boards on interior?

Chris, yes that helps - I've had several opinions by local contractors (Iwork in the code enforcement office) concerning righting the attic insulation. Some say definately change it others say it makes no difference - common sense tells me if it didn't make a difference there'd be no point in a vapor barrier at all. They all seem to agree that the majority of the heat loss is through the attic (which I won't argue, but the lack of insul in sidewalls has got to be a variable in the heat loss equation)

Which brings me to the next questions -

House has steam (radiator) heat and interior is "humid" -
When installing insulation in another home, I put up a plastic sheeting over the insulation (which had paper barrier attached) -

Do I need to do that with this house or will it increase the humidity?

Second - the cost per sq ft of blown in (for attic) appears to be substantially cheaper then rolled isulation - can I really get the same R value from blown as cheaply as it appears (about half the price)?

I don't mind the labor, know I need baffles and will be able to con someone into helping me (actually I have kids that still offer to help)
 
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Old 11-25-03, 10:11 AM
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I agree that if it did not matter why is the barrier there? I would turn it over.

Attic insulation is logically the first place to improve, if it makes economic sense. Payback, diminishing returns and all that. Next are the walls.

I don't know anything about steam heat and how it affects the interior of the house. I always think of it as being dry.

Ordinarily, the vapor barrier on the insulation is all you need.

Blown insulation settles a bit, about 5% - 10%, so that needs to be taken into account. The R- values published are for the insulation as it is supposed to be. The R-19 batts are supposed to be R-19. R-19 of blown insulation will be R-19 after it settles. It is important to make sure the blown insulation is measured by depth at application and that the right number of bags are applied per square foot. R-19 of cellulose will settle from 5.7 inches installed to 5.1 inches, for instance.

If 50 bags are supposed to be applied to the attic, there should be 50 empty bags after it is over.

If you think about it, there is less of a cost in packaging in loose as opposed to batts.
 
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Old 11-26-03, 06:41 AM
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If you are going to stud over the inside of the exterior walls, I'd would go ahead and remove the plaster and lath on these walls, too. No point in leaving it there.

But I agree with the idea to do the ceiling first. I just rolled out R-25 perpendicular to the 6 inches that were already up there (some fiberglass over some loos fill) in my house. I can't even begin to describe how much of a difference it has already made. House stays warmer, and the boiler runs much less now to bring up the house to temp in the morning. On milder sunny days, the boiler now only runs in the morning.

In a house that is 24 x 40, I installed about 25 rolls of R-25. The materials were less than $400. I'm guessing that I'll save that much on heating costs in the next two years. An estimate I got for blown cellulose was in the range of $1,000.
 
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Old 11-26-03, 07:12 AM
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foarm boards on interior

>It is important to make sure the blown insulation is measured by depth at application <

I guess the easiest way would be to tack in scrap pieces of lumber in each corner (and perhaps center?) at the correct height and run a string to them so I'd know when I have the correct height??

As far as removing the plaster and lathe, unless its highly recommended I'll be leaving it - its so messy and I'm afraid that I'll end up damaging adjoining walls or ceilings.
 
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Old 11-26-03, 07:28 AM
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Anther way suggested to measure depth is to hang ribbons from the rafters at various points with the ends cut to the target depth. I imagine many techniques would work.. I thought about tacking some scrap wood round and about cut to the right depth for reference.

I would not bother to tear out the old walls. It seems to be a great deal of trouble and mess with little to gain with only an inch in the walls.

Hope this helps.
 
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Old 11-26-03, 09:36 AM
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A single pipe steam system is the one heating system that adds moisture to the house. The air vented from each radiator before the steam reaches it contains water vapor. A good vapor barrier is important for the attic. The vapor barrier may not be as important for the exterior since you probably will not be able to get enough insulation into the walls to move the frost point into the wall. Enough heat will always be going out to keep the wall above freezing.
 
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Old 11-26-03, 11:16 AM
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I'm having a hard time visualizing how the house could be standing if the thickness of the wall framing that holds up the second story and the roof is only one inch thick. With one inch thick framing, there doesn't seem like there would be enough room in the walls for things like steam pipes, electric boxes, and windows, especially double-hung with hidden sash weights typical of these types of houses. Inside walls, maybe, but exterior walls???
 
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Old 11-26-03, 08:51 PM
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foam boards on interior? sidewalls

>I'm having a hard time visualizing how the house could be standing if the thickness of the wall framing that holds up the second story and the roof is only one inch thick. With one inch thick framing, there doesn't seem like there would be enough room in the walls for things like steam pipes, electric boxes, and windows, especially double-hung with hidden sash weights typical of these types of houses. Inside walls, maybe, but exterior walls???<

Okay lets start here - asbestos siding nailed directly to planks, the planking is at least 1 1/2" (it looks like very thick barn siding) there is about an inch of space between the planking and the strips of lathe then a good layer of plaster mixed with a substance that looks like horse hair - thicker then in the other homes I've done - but I'd have to measure...Then theres a sheet of plaster board, then a thin coat of plaster over that.

There are no weights in windows but you're correct that the frames seem nearly as wide as the side walls. The framing in basement and attic is pretty heavy, I'd say (and I know this is an odd measurement) 3.5 X 10.5 or 11 Framing is in excellent shape - again lumber looks like its right from the mill - sort of what I've seen in barn in Northern NJ.
 
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Old 11-26-03, 08:58 PM
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foam boards on interior? one more thing

>like steam pipes, electric boxes, and windows<

Steam pipes are all exposed and electric boxes are in floors.

We're had a rough time gettig boxes in exterior walls -which is part of the reason why when I do the 2nd unit, I'll be studding out exterior walls for insulating/running electric.

Also if you read the description of the wall structure- it may become apparent why I won't be stripping walls and will instead lose the 4 inches on the exterior walls.
 
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