Sorry, but a series of questions to follow. I am getting ready to start finishing my basement. (need to do myself as a short in funds)
1. I wish to move the main supply duct from the direct center of the room to the outside wall, which will shorten the extensions. Good or bad idea? (basically I want more head room in the center and I can build a soffit for the supply duct above what will be the sofa).
2. 9 inch poured concrete walls...do I really need to dry lock. I have heard many different answers.
3. Should I butt the 2x4 stud walls up against the concrete walls? I have 2 heard to ways. a) that a 1/2 inch gap should be between the concrete and the studs for air circulation....b) I should butt the walls together so there is no circulation.
4. Lastly, I have been told 2 things by different contractors. 1st I was told to put the vapor barrier between the concrete and the studs (so it would be concrete, vapor barrier, insulation, drywall) and then I was told I should not do that and to put the vapor barrier between the insulation and the drywall.
you will only get conflicting ideas on this subject. Things to consider. Basement walls are wet and will get wet at some point in their life. Build to the wall to allow everything to dry. Air space is necessary. Coat walls with two coats of water based dryloc. This blocks water transfer and is still permeable. Foam on the concrete will prevent capillary moisture transfer. Pressure treated sill to prevent rotting from direct contact with cement or metal stud track over foundation sill to prevent condensation is required. Moving the duct will not be a problem. No vapor barrier is to be used. But others will disagree. Mostly older contractors with experience but not up with new scientific studies. If you decide to use a vapor barrier it goes on the warm side of the studs behind the sheetrock. The foam board at the concrete will also help since it will prevent condensation at the concrete wall from warmer air hitting the colder concrete wall. Batt insulation can be used in this wall. However I recommend not using any materials prone to wet condition damage. Spray insulation is the best to use. You could also make your own SIP panels by gluing denshield and foam insulation to make a perfectly flat strong and water resistant wall that will have no problems in the future.