Replies

1. 
   saschafer | Mar 19, 2008 04:11am | #1

   Cover the concrete with extruded styrofoam insulation (the blue or pink stuff). You can adhere it with construction adhesive. Seal the gaps around the edges and between panels with minimally-expanding spray foam. If you don't plan to use the wall for mounting anything, you can just cover the foam with inexpensive paneling.

   If you do want to use the wall for mounting stuff, then at the very least you need to cover the foam with 3/4" plywood. Make sure that there is a moisture resistant sill plate of some kind (e.g., 1X3 pressure treated) for the plywood to rest on. Even better, build out a shallow stud wall with 2x2s (use pressure-treated wood for the bottom plate), fill the spaces between the studs with the insulation panels, seal the gaps with the foam, and then cover with plywood or drywall. (Rather than buy 2x2s, which typically look like pretzels, I'd buy 2x6s or 2x8s and then rip them down to size.)

   -Steve

    

1. 
   jbtx | Mar 19, 2008 07:03pm | #4

   Hi Steve,

   Thanks for your advice!  I have thought about something like this but have a concern: if the concrete walls get wet again, either from actual water coming through or via water vapor through the not-impermeable concrete, there would be no space for the H2O to go and mold would develop in that enclosed space between concrete and the insulation.

   What are your thoughts?

   Thanks again!

   Vivian

1. 
   saschafer | Mar 19, 2008 07:08pm | #5

   Mold will not develop if (a) there is nothing for the mold to eat, or (b) the mold-edible stuff has a chance to dry out.

   The insulation board-only approach satisfies the first requirement--there's nothing for the mold to eat. (Concrete doesn't care about getting wet--it is mold-inedible.) The building-out-with-wood-studs approach allows the studs to dry out between wettings (because you're not covering the wood with an impermeable membrane). Obviously, if there is permanent moisture, then you need to keep any non-treated wood away from that in some way.

   -Steve

    

1. 
   jbtx | Mar 19, 2008 07:58pm | #7

   Hi Steve,

   Thank you for this clarification.  I have hope again!!

   If untreated lumber is pressed up against the concrete and it gets wet, how does it dry out?  The part that is not exposed to air would get wet.  It seems to me that the drying to the interior side (side facing the shop room) would be so slow that mold would grow on the concrete-side of the stud.

   What do you think?

   Thanks again, Vivian

1. 
   saschafer | Mar 19, 2008 08:39pm | #9

   Well, that's what I meant about permanent wetness. You do have to deal with that. One approach would be to isolate the concrete from your built-up wall with a relatively thin layer of foamboard (1/2", for example). Seal all of the joints in that with the minimally-expanding spray foam, then build up the stud wall in front of that.

   -Steve

    

2. 
   jbtx | Mar 19, 2008 08:59pm | #10

   You are giving me another idea.  Would it make sense to spray the concrete with tigerfoam.com - spray polyurethane?  Would this be irreversible?  Would it be a fire hazard, I wonder, despite what the manufacturer might say?

   Thanks, Steve!

   Vivian

3. 
   saschafer | Mar 19, 2008 09:28pm | #12

   Yes, spray foam is a good choice. It's just a little harder to get a flat, uniform layer. It's also a bit more expensive (but probably less labor to install).

   -Steve

    

4. 
   jbtx | Mar 20, 2008 12:08am | #14

   Thank you, thankyou, Steve and Bob!

   Pardon my inexperience but I must ask: is this what you mean by foamboard?

   (home depot product url)

   http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100320343&N=10000003+503272+10039001

   -Vivian

5. 
   BG | Mar 20, 2008 12:30am | #15

   jbtx,
   I'm familiar with the type of problem you're trying to address. Bob Villa did a project in Melrose, MA (I think)last fall on a basement. He as going a lot farther than your talking (new family room)however, he did use a special material for the walls made like yours with a moisture problem. I wish i could give you a link but its been too long. You might find something on his web page.

6. 
   jbtx | Mar 20, 2008 12:39am | #19

   Hi BG,

   Thanks for the tip.  I'll search his website and see if I find anything.

   -Vivian

7. 
   KiddervilleAcres | Mar 20, 2008 03:00pm | #21

   jb,

   There is a warning on the sheets, mine are Owens Corning, that states it should be covered as it's not fire retardent.  OC recommends ½" drywall for most applications.

   Regards,Bob @ Kidderville Acres

   A Woodworkers mind should be the sharpest tool in the shop!

8. 
   jbtx | Mar 20, 2008 03:29pm | #22

   Bob,

   Thank you very much for this alert.  I am new to the use of this product.  I am very concerned about such safety matters and will proceed accordingly.

   Thanks again,  Vivian

9. 
   PeterThomson | Mar 20, 2008 05:48pm | #23

   Just finished doing similar work to my basement.  Used XPS pinkboard with Tuck Tape on the seams.  As long as the wall is (kinda) dry and doesn't have loose material on it (peeling paint, etc.) you can use insulation caulking to bond it to the walls.  You don't need much.  Be careful that the caulk/adhesive is specc'd for polystyrene... Polyurethane construction adhesive, for example, can melt your insulation boards.  (Yes, I found this out the hard way.)  Good luck, it will make a world of difference.

   I found this product online but there wasn't a distributor near me, looks like a good product:  http://www.ovrx.com/.  The flooring version might not be good below heavy shop equipment, though.

   Cheers,

   Pete

   Edited 3/20/2008 10:49 am ET by PeterThomson

10. 
    zolton | Mar 21, 2008 01:19am | #24

    There used to be foam panels made that had vertical "dados" cut or molded in them for furring strips. You'd hold the panel up to the wall and then nail a furring strip in the channel (actually through the channel and into the concrete behind it). No glues needed. The furring strip and its fastener would hold the foam to the wall, and because of the indentation, the furring strip would wind up being flush with the surface of the foam, ready to be drywalled.

    I seem to recall the foam was 1.5 inches thick, and the channels were 3/4 inch deep - just right for a 1x2 or 1x3 furring strip. There was one channel in the middle of the panel and both long edges were indented as well. That left the furring strips on 2 foot centers.

    If you're not able to find this type of panel locally or aren't able to order it, you could do much the same thing by just laying furring strips on panels of solid foam and fastening them to the concrete. That would leave a little space behind the drywall, which you could run wiring in. It would also eliminate heat transferrence between the cold concrete and any framing materials.

    These days, instead of the Ramset I used to use for this type of fastening, I'd be more inclined to use Tapcon concrete screws.

    ZoltonIf you see a possum running around in here, kill it. It's not a pet. - Jackie Moon

11. 
    jbtx | Mar 21, 2008 03:13am | #26

    Hi Zolton,Thanks for your installation tips. Presuming I can't get the foamboard with the dado I'll be using furring strips or something similar. Looking forward to getting this done! It will take me alot of time but I think I will be much more comfortable in the shop. This weekend I'll be seeing alot of Home Depots, I'm sure.Thanks,
    Vivian

12. 
    jbtx | Mar 21, 2008 03:10am | #25

    Hi Pete,Thanks for the info! I checked out the OvrX product on line - looks like a neat and efficient way to achieve a nice insulated wall. I called the local dealer - they stopped carrying the product due to expense so it isn't available to me, either. Nice idea, though.Thanks,
    Vivian

13. 
    saschafer | Mar 20, 2008 12:33am | #16

    The link you posted doesn't work for me.

    What you want is called extruded polystyrene foam (XPS), as opposed to expanded polystyrene foam (EPS).

    Extruded polystyrene foam is a solid sheet, and is typically either pale blue or pink in color (it depends on the manufacturer).

    Expanded polystyrene foam is made up of lots of little white beads that are adhered together. Expanded foam boards have a thin plastic cover that's intended to keep the whole thing from falling apart (but doesn't really work that well).

    You can use expanded polystyrene foam (it's a little bit cheaper), but it's a pain to deal with all of the little bits that break off.

    (You may also encounter another type of foam, called polyisocyanurate foam, that has better insulating qualities but doesn't deal as well with water.)

    -Steve

     

14. 
    jbtx | Mar 20, 2008 12:37am | #18

    Thanks, Steve - sorry the link didn't work for you but I'll try to post a photo of the product. I do believe it is extruded polystyrene. 

    -Vivian

    
15. 
    saschafer | Mar 20, 2008 12:42am | #20

    Yep, that's the stuff. You can sometimes get it pre-scored so that you can just snap it into the appropriate width pieces to go in between studs. (I used the pre-scored stuff to insulate some concrete walls inside a crawlspace, not because I needed to fit between studs, but because I couldn't fit full-size sheets through the entryway.)

    -Steve

     

16. 
    KiddervilleAcres | Mar 19, 2008 08:59pm | #11

    Steve,

    Back in the day when I worked for a commercial flooring contractor whenever we installed wood flooring (engineered not solid wood) below grade on a slab we always placed 6 mill poly on the slab first, followed by 15 lb. felt then the flooring on top, glued together.

    Sometimes sleepers were employed when installing solid wood on slabs.  The sleepers were pressure treated 2x4's with rigid foam insulation in between over 6 mill poly and the 15 lb. felt went on top of the sleeper/foam subfloor.  This system is also documented in an older FWW.  Why wouldn't this work on the walls?

    Bob @ Kidderville Acres

    A Woodworkers mind should be the sharpest tool in the shop!

    Edited 3/19/2008 2:01 pm ET by KiddervilleAcres

    Edited 3/19/2008 2:02 pm ET by KiddervilleAcres

17. 
    saschafer | Mar 19, 2008 09:32pm | #13

    Polyetheylene sheet works well, but is easy to puncture inadvertently (and without realizing it), which is its major drawback. The foamboard system is a little more forgiving in that regard. But as long as you can be confident that it will remain intact, then polyethylene is perfectly fine.

    -Steve

     

2. 
   SteveSheriff | Mar 19, 2008 07:56am | #2

   Perhaps you already found the great information at http://www.buildingscience.com. If not, go to their documents/reports and look at the basement insulation document:

   RR-0202_Basement_Insulation.pdf

   They do an excellent job of reviewing the moisture/mold problem you are worried about and they present insulation strategies to deal with it.  They also analyze some older techniques that do not work.

   Think about the cost savings as well as the volume loss when you think about interior insulation. When I insulated the basement in my new house (built in 2000), I knocked 30% off of my natural gas use by giving up 5.5" around the perimeter.

1. 
   jbtx | Mar 19, 2008 07:53pm | #6

   Hi SteveSheriff,

   Thank you for your reply!  Yes, I studied documents about insulation at that website when I had a less-than-informed and less-than-honest contractor to deal with re: attic insulation.  Very valuable info!  I will review the basement insulation info again.  Thanks for the reminder about this excellent resource.

   Vivian

2. 
   jbtx | Mar 20, 2008 12:33am | #17

   SteveSheriif,

   I just finished reading RR-0202_Basement_Insulation.pdf at http://www.buildingscience.com

   Brilliant!  I'm all about Extruded Polystyrene now!

   I'll do a google search for instructions re: how to adhere XPS to concrete walls.  If I can't get info I may ask you for more advice re: that procedure.

   Thanks to all of you so much!  I just might be able to feel my fingers while using my handplane next winter!

   -Vivian

3. 
   boilerbay | Mar 19, 2008 05:35pm | #3

   Just a thought,

   I had a house of the same era, workshop in basement. Granite/mortar walls. Open joist ceiling. Never could warm it up until... Low and behold, found 3 open runs above the exterior wall floor plates that had no fire stops in them. The air went all the way to the attic. Maybe left that way on purpose for ventilation/humidity control...whatever. Cut some blue foam insulation and fitted it into the 2 x 16 "channels".

   Shop became toasty. No humidity increase.

   John

   PS my furnace air intake was from an outside source.

1. 
   jbtx | Mar 19, 2008 08:00pm | #8

   Hi John,

   Thanks for your response!  I will make a closer inspection of the exterior wall floor plate areas to see if there is fire stop material there.  I feel like a detective.

   Thanks again, Vivian

4. 
   wilburpan | Mar 22, 2008 07:06am | #27

   I can't claim to be an expert, but it seems to me that one of your main issues with your basement is that it's a bit damp. My basement was dry, but the walls always felt a bit damp as well. When I set up my small basement workshop, one of the things I did was to paint the walls with Dry-Lok. After that, the basement felt physically less damp, and felt warmer in the winter for that reason. On top of that, the fact that the walls were now white made the shop seem a lot brighter.

5. 
   gb93433 | Mar 24, 2008 04:03am | #28

   You might get some great responses from contractors if you post at Breaktime.