[longtee81]

I have hired a Contractor who is near completion with framing 900 Sq Feet of basement space.

1) I am very concerned with how close he framed to the concrete since we are not using XPS foam and the walls are in some cases touching or very close to touching the concrete. Should I be worried, or asking that this wall be reframed and moved?

2) He is using fiberglass insulation, which I am OK with, but I just notice this evening that the product that is onsite are Kraft-faced Batts, which I believe are not appropriate for a basement job. Are these an issue?

Any help or suggestions would be much appreciated. I'm not sure if the walls can be easily move (since they are already nailed and glued) or if it is necessary. Our goal is to have a mold-free basement and I don't think I'm off to a good start.


Please see attached pictures....

 

[longtee81]

Links to Pictures: Hopefully these work now....

https://drive.google.com/open?id=0B2PWKz2IozBzSTVmQjd2VHMyNzQ

https://drive.google.com/open?id=0B2PWKz2IozBzU2ZhNUVQZnN2NkU

https://drive.google.com/open?id=0B2PWKz2IozBzZXBGbzh4Z0psc28

https://drive.google.com/open?id=0B2PWKz2IozBzWGtOSUQ2Q21jRnc

 

[longtee81]

Thanks for the very detailed and thoughtful replies!

I left some important info lout...
Location: Mid-Michigan (2009 IECC - Climate Zone 5&6 Marine
Home: Just over 10 years old. Basement wall were painted with Behr basement concrete wall paint about 9 years ago. I have not had any moisture issues an the basement has ranged from 50-58% without a humidifier (we do have a whole home humidified to keep humidity at 38% upstairs, which likely increases basement humidity.
Contractor: We are not doing any of the work ourselves and permits were pulled, so there will be inspections, etc.. I will definitely take a lot of pictures, so thanks for the reminder . He builds a lot of $500K + homes, but I get the feeling he does not make any adjustments to the basement since according to him "concrete walls are not wet", which I know is not the issue based on my readin . (It's the concerns on cold walls, dew-point, moisture wicking, etc...)

I have read all of the recommendations and published work of GreenBuildingAdvisor and the Building Science, and really would have liked to do the XPS taped foam (cost was not an issue), but all 4 Contractors I took down in the basement and spoke to, looked at me like I was an Alien when I suggested that they needed to do this, and said it was not necessary.

I am not a builder, so I apologize if I don't use the right terms here. The other framed walls against the Concrete are about .30 to .75 inches off of the Concrete. They appear to be glued and nailed from below and above, but they still have one more day of framing, so I'm thinking he will be adding additional nails on Monday.

Since I can't do it with the approach recommended by the PhD's, what's the best thing I could do at this point. Here are some things I'm considering (possibly a combination of these)....

1) Leave it as is, and just have him add some poly (only behind the wood that is touching the concrete)
2) Have him move the wall over about .5-1 inch so the wood has some space behind it.
3) Use a different insulation product (Roxul, unfaced fiberglass, spray foam)
4) Add an additional coat of a sealer (drylock, bayer, etc...) so it increases the chances the Concrete will not wick.

I'm really trying to focus on what I should do now and not what I should have done

Thanks for any help. This site is very great, and thanks again for all of your insightful responses!

 

[longtee81]

Is this done by temperature alone or also humidity control? I have a good amount of heat runs to walls down there and intend to install a subfloor as well so it should be fairly warm. I also have a whole home dehumidifier that I will be running.

Thanks!

 

[longtee81]

If 4 of your builders think as they do, maybe they know conditions in your area. And the photo wall looks really good for 9 yrs paint - even if just top shots. Paint condition near the footing? If same, you must have fairly good foundation protection and/or soil conditions. Think "finding out" frame of mind" than "what did you do wrong" and talk to your builder. Foundation is also never plumb and your wall should be, that is why different sets of gap numbers. Few tight shots don't tell any story, but so far framing looks very good.
Fire stops - fill the gap with rockwool.
Insulation - use unfaced insulation. But paper faced is also treated with tar and I've rarely seen high levels of mold growing on them, even wet, damaged. Fiberglass is inorganic. Your poured foundation is also more dense than a block foundation, which should also count toward better protection.
Sorry to tell you but you can't do anything toward vapor barrier at this point. You can't slip anything behind the wall and expect a good barrier. Plastic or anything else has to be sealed to the foundation, all dimensions, and that can't be done with the wall in the way, in a way that your builder will accept. Spray foaming the wall at this point is a bit of over reaction.

You can always test a certain area. Take a stud bay or two, can foam the gaps, cover with plastic sheathing, seal the sheathing and leave it for 2-3 days and see if there is condensation. Being winter, this may not be the acid test you need, but better than not doing anything. You can continue the test as the work progresses. Again, talk to your builder and be firm that you expect the test to pass, if not, must be rebuilt.

Even with xps encased foundation, you may have musty bsmt smell in summer. This may be unavoidable when bsmt is used as living room. I had to run the dehumifier all hours in summer and may be that is the price for bsmt living.

I assume you have bacteria controls in your whole house humidifier. When I bought a house with hot air heating, I checked its humidifier and it was slimy. I didn't want bacteria-cide in air so I removed it and put individual humidifiers in rooms with silver controls.

I really do hope it's an over reaction on my part! It's just impossible to find any online references that do not say wood in contact with the concrete wall is not a problem, or that taped XPS should be used. I will mention my concerns with the proximity and let him decide what to do. I do wonder if it will pass inspection though based on everyones comments. The township I'm in is pretty strict, so I'm sure they will look over it closely.

The walls have been very dry and comfortable down there. The paint looks the same (pretty new) all the way from top to bottom. I should add that most of the walls are spaced much farther away from concrete, it was just about 1/4th of the total exterior walls that have this issue.

I had invested over $1K in Santa Fe Advance2 whole house dehumidifier that can be vented from the utility room, so I will definitely set that up to keep the moisture levels down and control the dew point (thanks for the links and info SeniorSitizen). I wasn't aware of the bacteria issues with the whole home dehumidifier, that's something I will need to check out for sure! I did have the original "filter" in for about the first 7 years, and it was pretty disgusting when I realized they were supposed be changed out.

Since the R-13 Kraft Fiberglass is 3.75 inches thick, and would likely extend a bit beyond that in some cases could this be a good candidate for Roxul Comfortbatt r15 since it is only 3.5 inches and would provide additional insulation while keeping it's distance from contacting the actual concrete wall?

I know this is will not have vapor barrier and I'm OK with that (I'm almost positive that's agains our code here), but this to me seems like the best way to improve the situation.

Thanks all for you help and suggestions!

 

[longtee81]

Thanks Gary, this was a great deal of information, I will definitely be looking into caulking the gap between concrete wall/slab if he doesn't end up doing this.

Excellent links!!!