Advice on retrofitting insulation to old home? - PeachParts Mercedes-Benz Forum

R Leo · #1 01-26-2011, 07:56 AM

I have a rent house in Cameron. It might have a total of 3" of blown-in in the attic but there's ZERO insulation in the walls. The place has a 15kw electric furnace which runs almost continuously anytime the temps are near freezing and the utility bill is eating the resident alive.

Home is 1930-era stud construction with boxboard interior walls. At some point in it's past, all the wallpaper covering the boxboard was pulled out and cheap paneling was nailed over the boxboard. Don't really want to pull out the paneling (resident painted it all within the last year) but we've got to do something about improving the insulation.

Anyone here have any experience or suggestions on retrofitting insulation to an existing structure like this?

Stretch · #2 01-26-2011, 08:12 AM

Over here where lots of buildings are made of a concrete block - air gap - brick face construction they drill holes in one of these walls and then pump insulation into the air gap. May be you could find someone who can do that?

When this construction was first introduced (between the 2 worlds wars I think) it was used as a way of cutting down on materials. However, "they" quickly decided that it was to stop damp. They have now taken to putting in big sheets or rockwool when they are building this type of construction to improve insulating properties.

mbdoc · #3 01-26-2011, 08:23 AM

Start by blowing in at least 3" more in the attic area.

Then depending on siding type, you can have the interior walls blown in as well.

Imagine the windows are worse than the walls though.

R Leo · #4 01-26-2011, 08:38 AM

Quote:

Originally Posted by mbdoc

Start by blowing in at least 3" more in the attic area.

Then depending on siding type, you can have the interior walls blown in as well.

Imagine the windows are worse than the walls though.

10-04 on more attic insulation.

Siding is that pine rub board stuff. But what to put into the walls? Cellulose, foam? Do tell.

barry123400 · #5 01-26-2011, 08:47 AM

We own or have owned older houses with blown in fibreglass and injected foam insualtions. If the foam type in your area is the safe type that has no formadahydes and the cost is simular to blown fibreglass Thats what I would recommend. Gives you a partial semblance of a vapour barrrier as well.

One large older house we owned burnt 500 gallons of fuel oil a month in cold weather. After foaming the walls and not doing any attic improvement the fuel bill fell back to 250 gallons. The exterior holes for injecting the foam
where much smaller as well I think.

Usually always boils down to cost and availability in any given area. The foam does not settle in the cavities either but may shink a little with time I suspect is a possibility. The R or insulation value per inch is much better as well.

Cellulose insulation may become dampish since there is no vapour barrier in older houses depending on many factors. Talk to some insulation contractors in your area as well.

It is amazing what is really possible today. A neighbour of mine with a 7,500 square foot house pays approx 800.00 per year for his heating requirements. The downside of course is his heating system cost him 50k.

The house we are in now is 2000 plus square feet and thirty five years old. We heat it for 900.00 per year presently. It was ten below zero F the last few evenings locally. Probably the coldest it will get this winter. At the time I built it I did consider the future probable cost of heating in the future and am not sorry I did.

The last new house I built is 1300 square feet and heats for about three hundred dollars per winter. That can still further be reduced if wished but is not cost effective to do. Since I build some houses myself you have to really pay attention to details to achieve real efficiency.

One rental we have is a two and a half bedroom house. Tenants for years quoted it heats for less than one 200 gallon tank of oil. The house was built in 1954 and has the most intensive blown fibreglass insulation job I have ever seen when doing some work on it.

The average heating bill for a twelve hundred square foot house here is in the 2,500 to 3,000 dollar range.

my83300cd · #6 01-26-2011, 08:58 AM

I'd go for closed cell foam- because of the vapor barrier aspect. You dont want condensation inside the wall.

kerry · #7 01-26-2011, 10:51 AM

Blown in cellulose would be easiest I think. From the inside or outside hmm? Inside you could drill through the panelling at the same height on the outside walls and put a wide piece of trim on the wall over the holes. Probably simpler than drilling from the outside I think. Not a difficult DIY. Get your tenant to help and you could probably blow it in in a day.

t walgamuth · #8 01-26-2011, 10:57 AM

The only insulation I would recommend in walls and attic is fiberglass blown in. Cellulose will draw moisture and compact and critters like to nest in it. In an attic it will also blow away from any wind sources leaving bare spots.

In a crawl space I recommend blue styrofoam or any closed cell foam against the outside foundation.

R Leo · #9 01-26-2011, 11:03 AM

Quote:

Originally Posted by t walgamuth

The only insulation I would recommend in walls and attic is fiberglass blown in. Cellulose will draw moisture and compact and critters like to nest in it. In an attic it will also blow away from any wind sources leaving bare spots.

In a crawl space I recommend blue styrofoam or any closed cell foam against the outside foundation.

Understood on the difference in fiberglass over cellulose but, I'm concerned with the size of the holes needed for blowing in the wall insulation.

Tom, do you have any experience with the spray in foam?

dynalow · #10 01-26-2011, 11:29 AM

Years ago in the mid 70's, my parents insulated an old late 1800's farmhouse. Probably old balloon construction. Exterrior was cedar plank siding; interior was plaster lathe. I believe they blew in dry cellulose or whatever was used at that time, not foam. The exterior holes were about 2 inches, drilled with a hole saw and replaced. Not really noticeable. The house was 2 story with a plaster finished unheated attic, so no attic insulation was added beneath the old plank flooring.

They lived there for 25 years and had no issues with vapors or moisture. The NJ climate is generally dry, except for a month of humidity in August normally.

In an 80 year old house, how much does it make sense to spend?
It's already got 2 40 year lives under its belt!

kknudson · #11 01-26-2011, 11:39 AM

I would recommend first doing the attic.
It's a B** but if you put in R-30 Batts over the existing blown in, across the joists, it will be the most effective.
Most heat loss is through the ceiling.
If you get the encapsulted batts it reduces (not eliminates the itchy).

Blown in Foam or cellulose into the walls is a tough job, expensive if you have it done.
You may be able to rmove the upper piece of siding and blow it in that way.
A summer job but less damage to the interior.

We have about 2600 square feet, plus a 1650 sq foot basement. Most of the attic is close to r-50, the walls are insulated between the 2x4s r-19 ??? r-12, also replaced all of the windows. Good not great ones.
Natural Gas, 85 % furnace, gas stove, dryer, water heater, 2 furnaces (house and workshop) gas bill is 58 / month average.

TnBob · #12 01-26-2011, 01:52 PM

When you decide which way to go, please add... redoing all the windows and redoing all the door frames/seals.

Checking your work is another great application for your laser thermometer. You know, the one you got for checking engine temps.

You can check your doors and windows now to see what I am saying too.

The Clk Man · #13 01-26-2011, 01:55 PM

Quote:

Originally Posted by TnBob

When you decide which way to go, please add... redoing all the windows and redoing all the door frames/seals.

Checking your work is another great application for your laser thermometer. You know, the one you got for checking engine temps.

You can check your doors and windows now to see what I am saying too.

Andersen windows are the best.

dannym · #14 01-26-2011, 02:19 PM

Found this interesting:

http://www.oldhouseweb.com/how-to-advice/insulating-walls.shtml

Quote:

Before filling stud cavities of older homes with blown-in or foamed-in-place retrofit insulation, explore the construction. Stud cavities are often interrupted by blocking half-way up the wall, or in girt-frame construction, by full-depth diagonal corner braces. The outside walls may be "back-plastered," where a hidden layer of plaster creates two parallel cavities within each stud space, neither deep enough to receive loose-fill insulation.

After insulating, an infrared camera scan of the wall will show cavities that have not been fully insulated. Avoid deliberately ventilating walls, since any convective airflow within an outside wall risks condensation within the wall and compromises its R-value. Ventilation passages behind the exterior finish are called for when extreme interior humidity is expected and no vapor retarder can be applied, or where wood siding is applied directly over exterior foam insulation.

barry123400 · #15 01-26-2011, 02:49 PM

Quote:

Originally Posted by t walgamuth

The only insulation I would recommend in walls and attic is fiberglass blown in. Cellulose will draw moisture and compact and critters like to nest in it. In an attic it will also blow away from any wind sources leaving bare spots.

In a crawl space I recommend blue styrofoam or any closed cell foam against the outside foundation.

Tom, minumin attic code here is 15 inches of attic insulation for the last while. They do not specify the actual R value of the insulation used. We make a jig and insert 1 1/2 inch fitted foam 15 inches high or a little more between the truss members of the trusses. Then insert two layers of six inch batts of fibreglass insulation between. I then blow in to the top of the styrofoam truss filler pieces with cellulose. I get so much free 1 1/2 inch foam I tend to be creative using the stuff where I can.

Since todays shingles have a seemingly poorer resistance to heat. I tend to over ventalate the attic spaces. I hope that the cellulose forms a crust to prevent air ingress into the batts. This may help to mitigate some of the air flow through at least the upper portion of the fibreglass. I have a sneaky suspicion there are even convection type air currents at work. I kind of suspected this a long time ago when energy was cheap by comparison to today.

If there is another build and everytime I conclude one say never again.I will go back to what I used years before. Tongue and groove boards on the roof. I found those shingles lasted far longer than any since I have been roofing over basically solid face materials.

Two by six exterior walls do not meet code now here. Two by eight is the standard. Only low e argon gas filled windows allowed. And the basement walls must be insulated inside and out.

Not code but becoming far more common to insulate under the basement floor as well. This is all adding up to a build cost of around 175 a square foot currently including labour in my area if the house is contracted out. Over runs even on simple houses seem to be the norm.

I am also wondering if I should pull down a small commercial building we own and build a new super efficient one in it's place. I cannot fix the existing building. This one because of my age is a real toss up but even if reduced to a bare lot will still attract commercial taxes.

Maybe I will get smart and farm out part of the build this time. Twenty percent of the local population is now sixty five years old or greater. With a tremendous skill base and many do not want to stay at home.

A group of us could use this facillity for many things. I could use some space with a twelve foot ceiling myself.