Replies

1. 
   VaTom | Sep 09, 2007 07:17pm | #1

   I appreciate any thoughts

   Paragraphs are better.  Welcome aboard.

   I sold my 1911, structural brick building to someone else.  Efficient?  Wasn't gonna happen.  I built, no more month's income paying for our creature comforts.

   Good luck.

   PAHS Designer/Builder- Bury it!

1. 
   cotterresto | Sep 09, 2007 09:07pm | #2

   Well.....it's not that bad.   I know that the 14 inches of concrete are nearly zero R factor but there is essentially a structure within a structure with the 2 X 6 inner walls.  And concrete certainly stops wind drafts as well as vinyl siding!   Cheers. Tim

1. 
   VaTom | Sep 10, 2007 08:11am | #3

   You have 14" concrete?  Not exactly masonry.  Which is what I had, with plaster inside.  Mine was 2 story.  Peeked in the miniscule attic once and found 3.5" of fiberglass.  No idea how they got it in there, nor if it was uniform.

   I did some heat loss calcs on the building and the only thing that made sense was to add insulation on the outside of the brick, replace the windows, and figure out something for overhead insulation.  Plaster ceilings. 

   We moved to the country instead.

   Mostly, you're getting a "bump" from me to maybe get someone else's attention who would have some advice.PAHS Designer/Builder- Bury it!

1. 
   cotterresto | Sep 10, 2007 01:28pm | #5

   Thanks for the follow up.  I have already done Anderson windows and doors and long term as sprayed foam evolves, I will probably spray a 1-2 inch layer on the outside.  Right now with the first floor rafters visible, I'm trying to make my best inside decisions.  Tim

2. 
   JohnT8 | Sep 10, 2007 08:42am | #4

   Hi Tim, welcome to BT.

   Lets see if I'm following the situation; you're dealing with basement insulation and attic insulation, but the walls are already done?  

    I'm leaning toward 1 inch of closed cell foam between the 2 X 12 floor joists under the T&G floor which is over a full size basement with a dirt floor and 3.5 inches of open cell foam between the 2X 12 ceiling rafters. 

   OK, I'm not sure I'm following you here.  Are you talking about both the basement and the attic?  You mention your basement has a dirt floor.  What are the walls?

   You're saying you're removing the tin ceiling to insulate & wire.   What is your motivation to insulate between the first & second floor?  Are you not going to renovate the top floor?

   I'm wondering if I should add fiberglass batts below the sprayed in foam to increase the insulation at a more affordable price.

   Fiberglass is better than no insulation at all, but cellulose is also an option.  It provides slightly more R per inch and can be blown into knooks & crannies.  But I'm not sure of your situation, so am not suggesting any of them yet.

   If you've got pictures, try resizing 'em to about a 100k file size and post them.  Often a picture can save a lot of back and forth. 

   jt8

   "I was gratified to be able to answer promptly.

   I said 'I don't know.'"

    -- Mark Twain

1. 
   cotterresto | Sep 10, 2007 01:48pm | #6

   Yes, I have two separate insulation areas.  The first is the basement area which has a dirt floor, the walls are 14 inch poured concrete from basement to roof of this two story structure.  Since the dirt floor provides moisture (otherwise a dry basement) the foam installer recommended 1 inch of closed cell foam because it is essentially impervious to moisture penetration and seals all air leaks between T & G foor planks and is mold resistant. R value about 7.  I am considering the addition of unfaced fiberglass batts to increase R value with lower cost.  In this area the foam would face the floor of the first story.

   The next area is the ceiling of the first floor.  I'm taking down the tin ceiling to have access to insulate and wire and add fans/lights.  The second floor is a separate project and another 3200 sq ft to lose heat into. I don't anticipate having the second floor rehabbed for several years and it will always be considered a completely separate area to heat/cool. The foam installer suggested 3.5-4 inches of open cell foam here.  That again seals all air leaks and stops dust from sifting through the T & G flooring of the second floor.  Again I thought of adding fiberglass batts below the foam but in this case the foam faces the planks of the second floor, not the warm side (the first floor ceiling).

   Last,  I would like opinions on spraying the ductwork with open cell foam to prevent condensation on  the ductwork and to increase efficiency and to stop any unsealed leaks in the ductwork.   I hope this has helped clarify.

   Sorry, I don't have pictures and am currently 300 miles from the building. 

1. 
   VaTom | Sep 10, 2007 03:40pm | #7

   Much clearer description.  Easy to say that more insulation is better, but without identifying your major heat loss(es) you may be putting it in the wrong place.

   For instance, heat loss calcs showed that I over-insulated my exposed walls (underground house) compared to my low e glazing loss.  The next similar house we reduced the wall insulation, no appreciable difference.  For us, the way to get better performance is better windows, with 3 panes.  Or to do similar with window treatment, shutters or panels.  More wall insulation was wasted money.

   When it gets cold this year I'll be measuring various building material temps, but I expect it to only confirm what I calculated.  The temp sensors are very inexpensive.

   Are you doing anything for ventilation, or relying on leaks?PAHS Designer/Builder- Bury it!

1. 
   cotterresto | Sep 10, 2007 07:42pm | #8

   I'm installing new 92% gas fired furnaces and had not really given much thought to ventilation.  This would be the best time to deal with that if it is going to happen. I never thought that I would get things that completely airtight.

2. 
   JohnT8 | Sep 10, 2007 08:33pm | #9

   The first is the basement area which has a dirt floor, the walls are 14 inch poured concrete from basement to roof of this two story structure.  Since the dirt floor provides moisture

   You're right, there is probably quite a bit of moisture coming out of that dirt.  And in my area, there would also be radon and some other soil gases.  What do you plan on doing with the basement?  Storage, workshop, nothing... ?

   You current plan seems to be treating the basement like a crawlspace.  You're putting it outside the environmentally-controlled envelope.  If you're not going to do anything with the space, then that is fine. 

   However, if I was planning on using the space, then I'd probably look at incorporating it into the envelope.  A likely expensive option: put some XPS foamboard (pink or blue) across the floor and then pour a slab on top of that (and I'd probably put plastic down too prior to the pour..under the foamboard).  You could then foamboard the walls (I'd probably use EPS for that --white foamboard..cheaper than pink/blue).  That would make for a fairly tight and insulated basement and you then wouldn't need any insulation underneath the first floor.  You could then fully utilize the basement while still allowing for easy access to run ductwork/cables under the first floor.

   But maybe you're not planning on utilizing the space, or just don't have the budget to go full-blown.  In that case, if I was going to treat the basement like an unconditioned crawlspace, then I would make sure I did it all the way.   You mentioned insulating the ductwork, which is one of the items.  I would go ahead and put polyethylene plastic sheeting down (about $60 for a 20x100' roll) across the dirt floor.  I would also want ventilation.  Possibly 2 different ventilations: one for radon (if radon test came back high) and one for air. 

   I don't have any experience with the contractor expanding foam (hereabouts it is dang expensive if you can find anyone to put it in), but I suppose he could be correct in saying that the foam would provide a vapor retarder, and fg batts would probably give you the most bang for the buck in that application.  But keep in mind that the mold will get into your fg and floor joists. 

   Personally, if at all possible I'd rather try to find a solution to bring the basement into the envelope.

   The next area is the ceiling of the first floor. 

   Did you have to remove plaster, or was the tin ceiling mounted directly onto the ceiling joists?  Did you say they were 2x12's?  Let me see if I can get the attention of one of the 'crusty old experts' on this one.  For instance, I seem to recall Mike Smith blowing cellulose into ceilings.  If you blew the cellulose in tight, you wouldn't need the foam and could fill the cavities (you can find some of Mike's projects in the Photo Gallery section).  And if your foam prices are anything like ours, blowing the whole cavities with cell would probably be cheaper than 3" of foam).

   6k sq ft?  Sounds like a fun project.  Make sure you keep us updated (and we will need pics).  Once you get started, you could start a Photo Gallery thread.  And by the by, while I'm just a part-time 'remuddler', there are many full-time professionals that frequent this site.  Invaluable resource!  So if you don't get a response on a posting, try rewording it and post again.  Sometimes it is just a matter of catching someone's eye.   Occasionally someone will 'bump' your thread.  They are just pushing it back up to the recent threads so that maybe someone will see it and respond.

   jt8

   "I was gratified to be able to answer promptly.

   I said 'I don't know.'"

    -- Mark Twain

   Edited 9/10/2007 1:35 pm by JohnT8

1. 
   MikeSmith | Sep 11, 2007 06:21am | #10

   tim.... i'd probably run a comparison between the foam & blowing dens-pak cells into the  ceiling areas

   one of the problems is.. it's all or nothing.. with  the foam you get your 3.5"

   with the dens-pak you have to fill the cavity  ( 11 1/2" )

   i don't like FG.. the fibers are all condensing surfaces. so any moist air the gets below the dew point turns back into liquid

   anyways .. welcome to the neighborhoodMike Smith Rhode Island : Design / Build / Repair / Restore

1. 
   cotterresto | Sep 12, 2007 02:56am | #12

   Mike,  I plead ignorance what is dens pak?  Is that sprayed wet cellulose?  How does it compare in cost-any idea?  Tim

2. 
   MikeSmith | Sep 12, 2007 03:53am | #13

   dens-pak is just cellulose blown at a density higher than 3 lb/cf

   it is not  wet blow  or damp blow.. as that requires special equipment and delay from drying timesMike Smith Rhode Island : Design / Build / Repair / Restore

3. 
   cotterresto | Sep 12, 2007 10:32am | #14

   Mike, I've not heard of it in my area but will investigate.  Do you know it's R value at 11 1/2 inches and it's cost in your area?  Thanks, Tim

4. 
   JohnT8 | Sep 14, 2007 12:20am | #15

   I plead ignorance what is dens pak?  Is that sprayed wet cellulose?

   dens pak is basically just dense packed cellulose.  Whereas the typical cellulose application is to blow a fluffy, off-white pile into an attic; dense pack is where you're maximizing the blowers capabilities to pack the cellulose in as tight (dense) as possible.

   An example of dense packing can be seen with Mike's "Mooney wall".  Here is a thread on it:

   http://forums.taunton.com/tp-breaktime/messages?msg=65624.1

   My local Lowes carries Regal cellulose and blowers that are more than capable of dense packing.  Off the top of my head, I can't remember cellulose's "R" per inch.  I know it is better than fiberglass but less than foam.  Mentally I register it as slightly better per inch than fg.  It seals nooks & crannies better than fg.  Dense packed, it stops air infiltration.  Pricewise, it runs about $6/bundle.  I would guess it to be comparable to fg, but maybe Mike or someone else can chime in on that. 

   You might also poke around the Photo Gallery section for some of Mike Smith's threads.  Often he uses either the Mooney or a variation.  I remember instances where he blew cellulose between ceiling/floor joists.  Either with foamboard or insulmesh/firring holding it in place.

   Cell is just another option.  If I had the budget, I'd probably foam every sq inch that I could.  But since I don't have the budget for foam, I try to maximize my return.  And in several applications, that means cellulose.

    jt8

   "I was gratified to be able to answer promptly.

   I said 'I don't know.'"

    -- Mark Twain

2. 
   cotterresto | Sep 12, 2007 02:35am | #11

   Thanks for the response.  I tried not to add excessive information that might confuse things.  The basement is divided into front and rear sections roughly at the halfway point.  There is a concrete floor on the rear half and I heat it with a propane wall heater and it is my shop area.  I'm not too concerned about insulation here but will probably use faced fg later to reduce shop noise etc.  The basement walls are 50% below ground and dry with no mold etc.  I also have a dehumidifier running to protect all my tools/toys from the moisture inherent in concrete.  At the halfway point there is a 2 X 4 wall partition with green board and fg batts.  

   The front half is dirt and quite rough and sheet plastic or foam board would be a big job just to prep.   Since the building is 1910 vintage, any mold that was going to happen would have is my guess.  No evidence of anything but dust and spider webs.   The foam contractor is experienced and gave me several references for all foam insulated total electric homes with utility bills of $200.00/mo at 6500 sq ft.  He has also done small jobs for me in the past and he is meticulous about prep and spray.  He is also a great guy to deal with.  In my area owens corning 3 1/2 inch R 13 kraft faced fg is about 50 cents per sq ft.  6 inch fg is about 1 dollar a sq. ft.  And I have to install them.   Open cell Foam, installed is $1.30 sq ft at 3 1/2 to 4 inches and is much more effective than the R values would suggest.  Closed cell foam is about $1.30 sq ft at roughly one inch thick and is about R 7.   The more I read about fg the more I understand how often it is installed poorly.  I have never seen it installed the way the experts suggest and air infiltration would be a given.   I am willing to do it right but since foam has dropped in price so much in the last 2-3 years, it is competitive especially when installation costs are considered.  I hope this helps.