INSULATION AND THE WALL

james_6

I posted a question last month to the wall, I got great responses and alot of knowledge about convection and conduction. I have taken the advice from most of you. I have reduced my energy bills in my old home from 360 a month to 150 in the course of 2 months. I have insulated the old windows with weatherstrip, added insulation to the attic, foamed around attic spaces.

I would like to know if by adding an attic blanket across the joists the opposite direction will help, also, I will be insulating the hot/cold pipes in the unheated crawl will make even more of a difference?????????

You guys have been an unbelievable source of information and I have called out a heating/cooling contractor in my area to update an old boiler.

I just love you guys! Happy Thanksgiving!

Tracy

Uni R

Yes Yes

The cross layer is good because it slows the heat going into the attic through the joists themselves. Rock wool batts laid crosswise would be excellent to use if you can, since they they maintain a high insulation value even if damp. They also perform much better when it is truly cold out. R values are actually tested at something like 70*F. When air gets colder and denser it moves more easily through materials like fibreglass.


Insulating the hot supply pipes through unheated and heated spaces is always a great idea. Less water down the tap waiting for the hot water to start flowing. Insulating the cold water pipes in an unheated crawlspace probably won't change anything. In the walls it would be nice but under the house it may not be worth the bother.

james_6

Thank-you Uni R

Thank-you for the confirmation Uni! I just cant believe what a difference this insulation has made in my bills.

I added up my heating costs for the 2002 season.....I paid 3,658.00 last year. Because I bought an older home with little or no insulation. I had no idea what a real difference this would all make. Thanks for the confirmation and happy Thanksgiving to you and your family

[Deleted User]

insulate everything not moving..

ive a real fixer upper myself, and i'm tearing down walls and putting r-13 in the cavity..16 new windows installed thus far..so far ive reduced my gas bill 50%..and i'm not close to being done..but i did super insulate my attic just like you desire to do..Dan has a book in the books&more section of this site that may save you big bucks for the minimum investment on the book.. heres the link http://www.heatinghelp.com/shopcart/product.cfm?category=2-101

james_6

How much of an improvement can insulation really make in the attic of a home.........i think it's a lie

Boilerpro_3

Say Gerry...

If you really want to get the R-values up look into Blown in Rockwool for the walls. Its blown into the studs while the walls are open and then shaved off flush with the studs. If using batts, try high density fiberglass batts I belive you can get R-15 or better in 3.5 inch thickness. You'll probably have to special order them, though.

Boilerpro

chuck shaw

and you

are probally one of those people who think the moon landing was done a secret hollywood sound stage.

Chuck Shaw

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

[Deleted User]

well, being a plumber, not an insulator

i can only relate my experiance...it worked for me..but i look at the house as a system,,i'm not just working on insulating the attic, but also the walls,,and also updating windows,,and also redoing the heating system from forced air to hydronic..as i redo each room i install the heat emitter and piping..when i eventually have all the pipes in the basement i'll swich to a boiler..everything i do i keep track of its effect with a computer heatloss program..the house is a system, and insulating just the attic is only one component of the system.

[Deleted User]

thats interesting

i didn't know that could be done..what is it like spray foam shot into the cavity?

Steve Eayrs

Duke, PLease tell us what you have in your home for insulation. Would be real interesting to know why you feel this is a lie. Where do you live? Do you like to keep the inside temp. of your home the same temp. as the outside air temp.? What do you pay for heat bills?

Steve

james_6

i was adding insulation to my existing insulation. when i bought this place 3 years ago the previous homeowner had just installed central air. when i was laying the insulation batts, my wife came screaming from the house saying there was a river of water dump out from one of the bedroom registers. i had just moved one of the air conditioning ducts. what causes this???????? the ceiling wasnt wet, only inside the air conditioning duct. will this cause mold and mildew in the air conditioning system? also, how can i prevent it???
jerry

[Deleted User]

anywhere moisture sits for 48 hours

will allow mold spores to grow..its condensation in the duct..i'm not a forced air guy but it has to do with relative humidity..there may not be enough insulation on the ducting itself..

Boilerpro_3

Haven't seen it done myself...

I've only witnessed the results...a very airtight home with high R-value. The home was a single story 2,200 sq ft. ranch with 2x6 walls, full basement and attached two car garage and lots of south glass. I installed joist space radiant floor heating on the main level and in the insulated slabs for the garage and basement. The owner never got around to insulating the back side of the joist heating and it still had no trouble heating last winter here in Northern IL. I believe he said they only used 260 gal of propane in the worst month, which includes DHW, cooking, and dryer. See attached pic for the heating plant used.

There is some type of adhesive that bonds the material together and to the wall. I've seen a cellulose product like it used on exposed metal truss ceilings... they just spray it on and it stays there.

I wish I had this for my old home, however, we have 2x6 walls with very carefully fitted R-19 batts so my heat load for 2,800 sq.ft. with 700 sq ft of glass is only about 50,000 btu/hr at 70F delta T.

Best of luck on your money pit!


Boilerpro

[Deleted User]

thats a beautiful boiler

installation there BP..

Boilerpro_3

Thanks,

I think its the best one I've done for hot water. I keep trying to get better, and the folks like you here at the Wall are helping me get there!

Boilerpro

Mark J Strawcutter

convection thru system

assuming you have a separate/dedicated A/C system (ie not used for heating) you need to block off all supply and return openings during the winter.

Warm air rises up thru the ductwork (usually from second floor), hits cold duct surface in the attic, water condenses out, cold air drops back down thru ductwork (usually to first floor).

Mark

Greg Swob

Attic insulation

Duke-

I hear your concern on insulation. Remember that insulation is only part of the story - controlling (but not completely eliminating) infiltration is another major player in the building comfort goal. Experiment- go outside on a cold day-with no jacket on (no insul.), then go out with your heavy winter coat, but don't fasten it up (infiltration), then go out with a warm cap, scarf and button up your coat tightly. With which scenario will you feel more comfortable? (be sure to wear pants in all these situations - it may be an experiment, but your neighbors don't need to be scared or concerned about what you're up to). Whenever we perform heatloss/gain calc's we also do 'what if' scenarios - additional insulation and other factors, such as tightness and monitor the end results. After a while one experiences a point of diminishing returns, whereas the costs associated with additional insulation no longer provide a financial benefit.

All that said - it still amazes me that homes with little or no insulation still exist. Even after the tax credit days of the 80's, when we were PAID to insulate! In direct response to your position that insulation is not worth it - no offense, but you have been misinformed and hopefully we can help with the correct information. Do some calcs: contact your local utility (most ?all? will do energy advisory at no cost to their consumers) or a professional heating and/or consulting firm to perform a heat loss/gain calculation and plug in some variables - storm and/or insulated windows, attic insul. amounts, floor (in crawl space) insul., etc. Better yet, have a blower door and I.R. scan of your home done. The I.R. camera will show where you will benefit most with weather stripping and insulation. Honestly, in our area anyway, we sometimes see a greater benefit on attic insulation for air conditioning energy reduction than for heating up to a point.

Insulation- some is better than none, a lot is better than some, too much costs more than it's worth, but don't forget to work at reasonable tightening up while you're at it. Remember, high energy bills are not the problem, they represent symptoms of another problem(s). Greg

Jason Horner

Insulating foam

Take a look at this
http://www.fomo.com/products/largekits.html

R6 per inch

Comes in 2 varieties: fast rise and slow rise

Fast rise expands to full expansion in 10-15 seconds, so it's great for open cavities. Use this with a fan spray nozzle.

Slow rise expands to full expansion in about 60-70 seconds, and is really useful for filling closed cavities (eg. behind plaster/lath walls that you don't want to destroy or behind panelled walls. Use a 'pour' nozzle with this stuff.

Give you a couple examples of how we use it in renovations of older homes:


First we make a nozzle extension (see attached picture). Take the pour nozzle that comes with the kit and attach 12-18" of 1/4"ID poly tubing. Use a small hose clamp to cinch it tight. Then attach any length you need of 1/4" fridge icemaker flexible copper tubing to the other end of the poly tubing and cinch that with another small hose clamp.

You can also hammer the free end of the copper tube into a slit (fan) for a wider spray and/or drill tiny holes in the copper to force foam out sideways when you spray.



Plaster/lath over Brick
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From the basement it is often possible to slide the copper icemaker tube up behind the plaster. If you use a 10' section of copper you can get right to the ceiling of the 1st floor. Pull the trigger on the dispenser and slowly withdraw the copper tubing while wiggling it side-to-side.


If you can't get access from the basement, often you can drill 1/2" holes behind brass weatherstripping that old windows and doors have and pop into the cavities laterally.

Drill about 3 holes in a standard sized doorframe, starting about 2' from the floor and spaced about 2' apart vertically. If you use an 'installer' bit you can drill a long way horizontally.

Put a curved bend in the tip of the copper so the opening points down. Then fish your cooper tube nozzle in as far as you can and shoot a small amount of foam - the foam will make it down to the floor and start expanding up. Withdraw the extension nozzle into the next stud cavity closest to you and shoot some more foam, and so on. Give the first cavity you shot foam into about 75 seconds to expand and then you can shoot some more in that one.

In essence you wind up 'layering' foam in about 12" 'lifts'. This way you don't shoot so much in as to blow the plaster off the walls or cause the walls to bulge

Plug the holes drilled in the door/window frames with glued-in doweling when you are finished.


Hollow cavity on 2-by construction - same room application
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Drill a 1" dia. hole in each stud cavity 1-3" below the ceiling. Instead of a copper extension nozzle, just attach about 8 feet of poly tubing to the pour nozzle. Tape a lead fishing sinker to the tubing near the free end and then lower the poly tube through the hole. Shoot some foam, pull the tubing out 12", wait 75 seconds and then shoot some more foam, and so on.

When you are done you can either patch the holes and repaint or install 'crown molding' where the ceiling/wall meet and dress the room up.


Hollow cavity on 2-by construction - applied from above
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If you have access to an attic you can drill through the top plate of each stud cavity and fill with foam as indicated above using the poly tubing and sinker trick.


Other Tips
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Since the foam can spray up, you can use similar techniques to insulate cripple walls, dormers, window seats, sloped roofs. Just don't drill so many holes as to weaken the structure. The foam is also a vapor barrier.

In rooms with rads that have attic crawl spaces behind the rads, we often put a piece of the foil-bubble radiant barrier up against the backside of the plaster and then foam it in place.

You have to experiment first on a section of mock-up wall to determine how fast to withdraw the pipe so you don't pump too much foam into the narrow cavities (cavity depth behind the plaster can vary from house to house. Also remember that with lath on brick, the 'studs' are often just 1" x 2" every 3 feet so your cavities are wider than typical stud frame construction.

With a little practice you can get cavities perfectly filled even when you can't see what's going on. Even if you can't get much insulation thickness installed this way, it will cut down on significant amounts of air infiltration.

Just remember to check for sufficient combustion air and CO levels in the house as you seal it up.