Replies

1. 
   MojoMan | Nov 15, 2003 12:07am | #1

   What kind of insulation are you using? Fiberglass? Does it have a vapor barrier? I live in a house with half-finished projects all the time and it doesn't bother me nearly as much as it does my wife. If you are concerned about fibers, you could put 4-mil poly over all the insulation to seal things up. This will also serve as your vapor barrier later.

   Al Mollitor, Sharon MA

1. 
   davekaplan | Nov 15, 2003 02:30am | #5

   Thanks for the reply.

   Its an old 2x4 wood frame, I've got about 4". I have not purchased the insulation yet, I saw the 3.5", 15 x 96 fiberglass batts. There were a couple different R-values for the 3.5" thick material. They all had a paper face.

   "If you are concerned about fibers, you could put 4-mil poly over all the insulation to seal things up"

   I think that is a good idea.

   Thanks again.

2. 
   Mooney | Nov 15, 2003 12:34am | #2

   I thought I was responding to a drywall issue , but since you mention and ask it ;

   I bought insulation from Lowes on a new house I built that was completley plastic wrapped!!!! The only issue I can think of is rubbing against it which makes me think of the skinny dipping days after putting it in. Seems the old rules still apply around here is to "break in ", the new or young help with this job. Reminds me of" haising". Seems it was part of growing up on the job.

   On another subject , if you are married , you better hurry with those windows and drywall my man !!!!!!

   Tim Mooney

1. 
   xMikeSmith | Nov 15, 2003 02:06am | #3

   hey, tim... how ya doing ?  nice to see your smiling face around

   and you could get some spun fiber mesh and glue it to the studs and blow dens-pak cellulose into your stud bays.. here's what it looks likeMike Smith   Rhode Island : Design / Build / Repair / Restore

1. 
   greggo | Nov 15, 2003 02:22am | #4

   Hey Mike how hard is that to do!You got me thinking,that maybe I will do my own house.Did you use a special blower?or can you use a rental type?Where do you get the mesh and glue?Does the mesh hold tight so there is no bulging? Big Fire In RI today,be carefull                               Thanks Greg

1. 
   xMikeSmith | Nov 15, 2003 04:45am | #9

   i was comming back from Coventry and could see the smoke in Pawtucket from Rt 2..

   we use a hurricane blower and and old US Fiber machine..

    a good rental machine should do the trick..

    the new fiber mesh is a LOT cleaner than the 1/4" mesh..

    I buy the fiber mesh from Regal Industries in Indiana.. and the latex glue from the same place.. you staple the mesh and then roll the glue on like paint next day you blow the wall...

   we get all our cellulose from Insul-Mart..

    here's roy running the blower .. and the insul mesh stapled up... and the glue being appliedMike Smith   Rhode Island : Design / Build / Repair / Restore

   
1. 
   donpapenburg | Nov 15, 2003 06:03am | #10

   I had seen that stuff but could not buy it any where around here . So on a small job I had to do I stapled up fiberglass screen and packed the cells in till it looked pregnant , and I looked like the guy in one of your 1/4 mesh pics. Then I installed  the drywall for a real denspack.

2. 
   greggo | Nov 16, 2003 03:28am | #11

   Thanks for the pics.The mesh almost looks like filter fabric(or mirafi paper)?Is there any special way to do the switch and outlet boxes?Can you do both sides of an interior wall?I imagine you start at the bottom and work up?I don't mean to take away from the original posters question,but this technique is Hot!

3. 
   xMikeSmith | Nov 16, 2003 07:37am | #12

   outlet boxes  we just cut  in careful and sometimes glue some reinforcement around them..

    you  can also use a temporary furring in locations that may want to bulge...

    the insul-mesh / glue was pretty much foolproof..

   here's 2 pics:

    the darker one shows some silver material nailed to the ceiling to form a box under the 2d floor kneewall area.. then we went up on the 2d floor and blew it thru holes drilled in the sub-floor... same technique around the band joist on the first floor

   the 2d pic shows the blow pattern ( thru holes made with a utility knife ).... and also a typical switch box...

   and yes , you can blow double sided walls.. see the next post

   Mike Smith   Rhode Island : Design / Build / Repair / Restore

   Edited 11/15/2003 11:37:38 PM ET by Mike Smith

   
4. 
   xMikeSmith | Nov 16, 2003 07:42am | #13

   gregg.. here's a double sided wall... this exterior wall became an interior wall, and we wanted insulation in the old window opening for sound control between the two bedrooms..this was with the old 1/4" mesh... the insul-mesh works even betterMike Smith   Rhode Island : Design / Build / Repair / Restore

   
5. 
   greggo | Nov 18, 2003 03:12am | #14

   Mike I noticed that you were using some strapping on the ceiling in one of your pics. I'm doing it in my house so the joist don't twist and for a better target for the drywall,but anyone else that see's it keep's telling me that I don't need it

   Also do you ever insulate between a 1st and 2nd floor (1 for warmth, 2 for sound deadening

   whoops : one more-are there any precautions dense packing around a fireplace and chimney

   Thanks Greg

6. 
   fortdh | Nov 18, 2003 04:57am | #15

   Greg, Mike,I would certainly insulate the rim joists between 1st and 2nd floor.

   I prefer closed cell polyurethane sprayed foam at 2# density, which yields R-7 per inch. A couple of inches backed up with fg batt is a very cost effective way to get good sealing and high R-value at the perimeter.

   As for the rest of the space between floors,a friend with cash to burn, had all his interior walls and space between floors fully packed with fg about 25 years ago. The house is very quiet inside! It would help retard air flow into partition walls above through wiring/pipe openings, which then reach the attic.If nothing else, I would can/foam the openings.

   I recommend bathroom walls, especially a powder room off kitchen or den etc. have at least some R-11 for sound deadening.

   Have you noticed that vapor barriers are well discussed for walls up to the ceiling, but rarely, if ever mentioned for the rim joist exposure between floors?

   How many houses have you seen with a vapor barrier in the first floor ceiling to keep moist air from condensing on the rim joists?

   Re chimneys, there are specific codes on what visual exposure has to remain open. I have seen rock wool stuffed in, but I would ask local inspector for his input. PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home

7. 
   greggo | Nov 21, 2003 06:10am | #17

   Paul: I definitely will do the rim joist.I was also seriously considering the whole area between the 1st and second floor in cellulose.I was thinking of ripping a 15" slice into the sub floor (3/4" t/g plywood ) perpendicular to the 1st floor ceiling joist after the ceilings were rocked. I would then shove the blower hose left and right of the cavity till it filled up.I have a lot of recessed cans ,but they are all I/C

   As far as foam goes,  #1 in my are a CT its wicked expensive($17,000) for my house #2 I don't think they would come out just for the rim or band joist.

   You are right about the vapor barrier.

   Thank you  for your input

8. 
   fortdh | Nov 21, 2003 07:45am | #19

   Greg, I couldn't blame a foamer for not wanting a bigger job than

   one band around the house, but geeze, $17,000 for the house! Did you tell them they could have the truck back, you only wanted the foam... How many sq. ft. at what thickness? I know CT is expensive; I have a semi/client in Riverside, and every little repair is gold plated. Around here, 1" of polyurethane closed cell is about $1.90 sq ft. So, a 40 x 50 house with 8' ceilings would have 180' perimeter times, 8 = 1440 sq ft, x 1.90 = $2736.(and that disregards windows and doors)

   I take it you really want the sound deadening enough to rip some floor and attempt a blow-in of cellulose. Other than the rim, if you seal all holes heading north, I don't think you will get pay back in energy savings from the insulation, but doing it yourself probably won't be a big cost, and sometimes we do things just because we want to.

   Could I suggest that you consider pushing poly wrapped fg in the joist space from any potential cellulose blocker( cans, x bracing, plumbing lines)to the rim joist. Then you will not wonder if the cells got past the IC cans in that particular bay and you can blow-fill to that point with cell. Or, could you staple a reinforced kraft to the ceiling, and work across the ceiling in 8-10' sections, then sheet rock?

   I had a client who wanted a garage /den wall foamed with one inch before the rock was up to spray against. (schedule conflict) So we stapled a barrier of reinforced kraft/string mesh/foil barrier to the studs, and the foamer was able to spray against it. The same should support cellulose loose blown in.

   Good luck to you, and have a good Thanksgiving. I get to spend a week with the best results of my best project, my grand children.

   PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home

9. 
   greggo | Nov 22, 2003 02:33am | #27

   Paul: the sq footage of the house is 3100, the wall thickness in the quote was 3 1/2"

   (How many sq. ft. at what thickness? )

   Also I'm not a big fiberglass fan so I wont be putting any in the house.

   I'm still a little miffed that I have it for the a/c flex ducts(concerned) about it getting into the airstream.

   I figure that I won't get much of a payback if I do the 1st floor ceiling,but the sound deadening should be pretty good,especially if I put in some strapping perpendicular to the joist (Breaking the thermal bridging).Also it should quite the pipes a bit.I noticed that the i/c cans do have some slots in the I was wondering if the cellulose would leak thru them?

   Oh yeah  have a Happy Thanksgiving too!

   Edited 11/21/2003 7:51:12 PM ET by GREGGO10/2 10/3

10. 
    fortdh | Nov 24, 2003 06:58pm | #33

    Greg, sorry to just now replying, been on the road for a few days, at sisters in Alabama for a few. Got to see Auburn beat Alabama.

    Your flex ducts probably have an inner liner, so no air in contact with glass, however, if you have duct board trunk lines, you do have air/glass contact.

    Do you seem slots in the outer shell of the IC cans, or just bezel connecting slots inside the cans? Cellulose gets into some pretty small openings. I wouldnt want it inside the outer can.

    Not knowing your cost area, but I would assume sprayed cellulose for walls to be less expensive than sprayed closed cell poly, with some loss in R-value and stiffening. I noted in the latest FHB issue, that the "better wall" had 2" of foam boad on the exterior of sheathing, in addition to cell walls. We need to do some cost/R-value/air sealing analysis of various configurations, and come up with the best package for the $ in a variety of climates.

    I certainly agree with other posters who point out that R-xxx with sprayed foam is a lot better than R-xxxxxx of fg. Now, where is the best balance point of value.

    You are going to have a pretty quiet ceiling. Paul

    Energy Consultant and author of Practical Energy Cost Reduction for the Home

11. 
    xMikeSmith | Nov 18, 2003 05:43am | #16

    greg.. in reverse order...

    most codes that i'm aware of require a 2" space against the chimney   OR  an approved  non-combustible material

    we block out for the band joist and create cavities that will surround the  perimeter joist bays..

    and as to strapping.. no , you don't need it.. but it sure is nice to have.. it's a regional thing... New England mostly.. i have never built a house or addition without strapping the ceilings..

     that 3/4" space lets you do a lot of things.. especially in tricky ceiling details.. want to hang a ceiling fan ?.. nail up a piece of 3/4 ply.. easy if your ceiling is furred

    so, those that say you don't need it are absolutely correct.. just tell them " oh stupid me, next house i won't waste the money"   

    someday , real soon, i'm going to make a list of all the reasons to strap a ceiling.. they are legionMike Smith   Rhode Island : Design / Build / Repair / Restore

12. 
    greggo | Nov 21, 2003 07:05am | #18

    Mike : if I wanted to ,would there be any reason not to do the whole ceiling area between the first and second floor?I over kill everything LOL

    Also I have a ton of recessed cans rated I/C can the cellulose just blow right over them?

    And can I some how be adopted into your family I'm a good  cook LOL

    Thanks Greg

13. 
    xMikeSmith | Nov 21, 2003 03:31pm | #20

    greg.. we've done that.. but as paul says.. it's difficult.

     the last time we did that was a bedroom & bath over an unheated garage..

    we drilled holes in the band joist and blew it from both side3s with 8' extensios on the hose..

    as to sound deadening.. a foam gun  and absolute sealing of ALL penetrations will do almost the same thing...most of the sound transmission is thru the framing..

    if i was paid to do what you are talking about , id probably cut slots in the ceiling ( or the floor) probe each bay , push the hose to the end and back it out... you can see the flow and hear the change in the blower so yu know when you're getting the density you want...

    then pack teh last slot area by blowing thru a piece of plywood pressed against the ceilingMike Smith   Rhode Island : Design / Build / Repair / Restore

14. 
    greggo | Nov 22, 2003 04:04am | #30

    Mike : if I do the slot thing ,which I probably will,do I have to consider any weight problems on the sheetrock with the extra weight of the cellulose(the joist are 2x10)

    And can I blow right over the I/C cans?

15. 
    xMikeSmith | Nov 22, 2003 06:33am | #32

    at dens-pak.. i think we figure 3.5 - 3.7 lb. cf... we've never had a problem blowing blueboard off the ceilingMike Smith   Rhode Island : Design / Build / Repair / Restore

16. 
    xMikeSmith | Nov 21, 2003 03:32pm | #21

    as to the adoption... do you remember "Maggie's Farm".... bob dylan ?Mike Smith   Rhode Island : Design / Build / Repair / Restore

17. 
    Paularado | Nov 22, 2003 12:35am | #23

    Mike,

    Maybe you mentioned it somewhere, but do you put a vapor barrier over the insulweb? We had dense pack cellulose put into our cathedral ceiling and they used this stuff.

    Anyone know if the insulweb is flammable? I guess I could just tear off a little corner and find out....

    I think reading your enthusiasm for cellulose over the years probably influenced our decision to use cellulose. We absolutely could not be happier. It makes fiberglass look like an antique. Thanks!

18. 
    xMikeSmith | Nov 22, 2003 12:59am | #24

    no, paula, i stopped using vapor barriers when i stopped using fiberglass..

    i don't know about the flamability of the insulweb... but it's a good question.. i don't think the insulweb could support a flame with the cellulose in contact with itMike Smith   Rhode Island : Design / Build / Repair / Restore

19. 
    Paularado | Nov 22, 2003 01:11am | #25

    Thanks for your quick reply!

    Maybe I'll cut off a little piece and see if it will light.

20. 
    greggo | Nov 22, 2003 01:41am | #26

    Paula : I don't think there is that much of an air space if any from behind the sheetrock to the studs and cellulose bays.I think the insulweb might melt more than anything.I'm not a contractor but I'm a firefighter and all burn questions are a concern for me.

    I have tried to set  a hand full of cellulose on fire with a torch , it smoldered lightly and went out.I then tried a piece of icecene foam and it to also melted BUT! the SMOKE it produced and I do mean SMOKE had to be toxic.

    Let us know how your test goes.

     Greg

21. 
    greggo | Nov 22, 2003 04:07am | #31

    Its been driving me nuts all day ,I know the song but not the words.LOL

    And Thank You!!!

    Edited 11/21/2003 8:16:19 PM ET by GREGGO10/2 10/3

22. 
    fortdh | Nov 21, 2003 07:46pm | #22

    Greg, OK, now that I know you take my often overkill approach, between Mike and I, we will help you spend some bucks and get this project gold plated. Fill the holes first, as that stops the air flow and some sound trasnsmission. The light cans also allow sound to penetrate. I know they are rated IC, but I feel better with a thin wrap of fg around them prior

    to cellulose. The greatest sound transmission is from the rock/joist sounding board it creats.

    You could strap the ceiling with 1x4, using some silicone caulk as a thin cushion at each contact point, and then the rock.Or, you could (have never tried this,but think about it) staple something like tyvek on the joists, and fill sections as you go with insulation. Strap as you go as well, thus supporting the tyvek/insulation every 2 ft.

    Mike is approaching the fill from above, I'm approaching it from below to avoid the holes. If it was my task, I would push poly wraped perforated fg rolls into place, and probably strap the ceiling. Have always liked the support strapping gives the joists, and the wide target for the rock.

    Have we about filled you turkey day free time? Have a good one. PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home

2. 
   MojoMan | Nov 15, 2003 02:56am | #7

   Mike: Have you had any experience with two-part spray-on foam insulation? A friend of mine just had it done in Jamestown RI and is pretty happy with it. He says it fills all the nooks and crannies and also serves as a vapor barrier. Only downside so far is that now he needs an air-to-air heat exchanger because the house is so tight.

   Al Mollitor, Sharon MA

1. 
   xMikeSmith | Nov 15, 2003 04:35am | #8

   al, sounds like you're talking about icynene foam.. some people swear by it... big  $$$.. wud u believe i've lived in Jamestown for 50 years ?

   me.. my favorite is cellulose..... but icynene is a good choice

   here'z a couple pics of the old style... this is  a 1/4" nylon mesh, stapled & glued with PL200..

    then you blow thru a hole in the mesh.. the mesh clogs & dens-paks behind the clogsMike Smith   Rhode Island : Design / Build / Repair / Restore

   
2. 
   davekaplan | Nov 15, 2003 02:35am | #6

   if you are married , you better hurry with those windows and drywall my man !!!!!!

   You know it!! I can't believe she is letting me do this to the house.

3. 
   reinvent | Nov 22, 2003 02:56am | #28

   This just in.

   The new issue of fine homebuilding has a good article on the pros and cons of all the differnt types of insulation discused.

1. 
   greggo | Nov 22, 2003 03:48am | #29

   Damn mailman is always late!

4. 
   csnow | Nov 24, 2003 10:32pm | #34

   Kaplan,

   The main thing is getting the top ceiling plugged up.  If the ceiling was made airtight, you could probably get by with open stud bays (depending upon just how 'open' they are).  Perhaps some minor air plugging up on the walls would be adequate.

   Cold air will not tend come in if it has no place to go.

   Consider putting up a layer of foam board on the underside of the joists.  Seal the joints between the panels with spray foam and/or a good tape.  When it comes time to to install the rock, you can put it right over the foam.  Bonus insulation, no wasted work, no dust...