Insulation, most bang for the buck.

[phil harold]

strip and do it right...

http://www.buildingscience.com/docum...e-perfect-wall

[Greg R Bradley]

No answers are possible without knowing your climate. That is critical to even guess about solutions.

Is the stucco directly on the cinder block? Is there a drainage plane behind the stucco? Is there a vapor barrier or a vapor retarder on the insulation board?

Temperature AND humidity will always try to equalize. Hot will always flow to cold (less hot). Wet will always flow to dry (less wet). If it gets cold outside you can count on a dew point somewhere in between inside and outside.

[Jim German]

Can you get foam in without pulling down the Sheetrock?.

Sure, they have a slow rise type of foam that you just have to drill some holes in the wall and then later patch.

[Jim Andrew]

There are questions that need answers. What is the " insulation board" product? If it is a closed cell styrofoam, it is a vapor barrier. And we need to know what area of the world this building exists in. If it is Canada, better strip the walls down and go with fiberglass wall insulation. And you need to ventilate the attic and add to at least R 38. Most areas need attic ventilation, it keeps the insulation dry so that it works. When moisture collects in insulation, the insulation value goes away, and can cause the lumber in the building to rot over time.

[Joe Hillmann]

There are questions that need answers. What is the " insulation board" product? If it is a closed cell styrofoam, it is a vapor barrier. And we need to know what area of the world this building exists in. If it is Canada, better strip the walls down and go with fiberglass wall insulation. And you need to ventilate the attic and add to at least R 38. Most areas need attic ventilation, it keeps the insulation dry so that it works. When moisture collects in insulation, the insulation value goes away, and can cause the lumber in the building to rot over time.

The insulation is a fiber board, I am in northern Wisconsin so am much more worried about keeping cold out than in. In the attic the brick wall continues about five feet above the ceiling, with the roof and soffit vents above that so I can push the insulation all the way to the walls without problem.

[Rob Fisher]

Phil, has it right, to strip down and do it right. Assuming you don't want to do that, it becomes harder. Building science knows there stuff, definitely read as much of as you can.

Assuming the eaves are above the ceiling level, you can (and should) insulate right up to the outside walls. You need an air barrier for the ceiling too. Either remove the blown in and put in the air barrier (then reinstall/add more blown in insulation), or look into air tight drywall (it's a method of install not a product).

The walls are signifigantly more challenging. The biggest problem is if you insulate on the inside of a structural masonry building (I'm assuming the block is the structure in your description) you leave the masonry cold, and probably wet, during the winter which leads to freeze thaw damage, which I am sure could be an issue in your northern location. Best to insulate masonry building on the outside in cold climates.

The other big problem with stucco over masonry is vapor drive from sun driven rain, exterior to interior.

Overall it would be best to engage someone with experience and knowledge on how to deal with your specific situation. Without actually seeing the building all of us are just speculating what might work.

[Mark Bolton]

These insulating issues usually devolve into chaos but my input (GC cold climates, 20+ years in the trade) is:

It sounds like you are like any of us and budget is of course a concern which would likely rule out gutting the entire space and starting over and, depending on local availability, will also likely squash spray foam. Spray foam can be installed in the existing cavities and even though its the best performing option and payback is high, its often times far more costly than most are willing to spend.

The vapor issues are definitely a concern for anyone in a cold climate. Its true you dont have showers, cooking, and so on in the space however assuming the building is a slab there is likely no vapor barrier under the slab as well which means you can have substantial moisture gain through the slab. For that reason, yes, you want to be a bit concerned with moisture however also as has been stated, a well sealed and painted interior can act as a substantial vapor retarder (prime and two coats of paint).

With regards to the fiber board insulation you already have I would consider it negligible. Im not sure I understand the foam board assessment. Usually pink or blue are extruded iso which are lower in R-value but mainly designed for exterior applications where the foam will be in direct contact with earth and have a higher compressive strength. Can absolutely be used on the interior but if the extruded is not needed higher R value products exist. ISO is the yellow with the foil which is the highest R value and of course has an applied foil vapor barrier but is less common at least in my area due to cost. It is the closest foam board you can get to spray foam. Polystyrene is the white pill stuff, same as a styrofoam cup, which is absolute junk, very low R value and a termite magnet. If you had ISO (yellow) you would have the highest R value at approximately R7-8/inch.

Personally, if it were me, and you are going to repair the drywall, air seal, prime/paint, and dont have full access to the entire wall cavity, I would simply blow in cellulose. Its of course no guarantee but given the use, and the fact that you are unlikely to get the building tight enough to have a major issue with trapped moisture in winter, you would likely be fine. You can always install a digital hygrometer and monitor your interior humidity.

Your biggest bang for the buck will likely be air sealing and adding as much insulation to the attic as possible.

Just my $0.02

[Mel Fulks]

Agree with Mark .Some stucco is pretty good stuff ,I've never heard of it having the problems we have seen on the news shows with drivit.

[Joe Hillmann]

I think at this point I am just going to seal up air leaks and add more insulation to the ceiling. There is no way I will be removing all the sheetrock just to insulate and maybe save $20 a month 5 months out of the year. Spray foam is also out due to the cost. When I planned to do dense pack blown in insulation I had planned to spend $500-$600 on insulation and machine rental and though that may be hard to justify in energy savings but now that I am also worried about it causing moisture problems I think I will
instead seal air leaks.