Hi,
Insulation:
#1.) The insulation is absolutely FINE the way it is.
Tho, it is best to have a 1-2" ventialtion air space between concrete and un-faced insulation, the present vapor barrier on the exterior side of your insulation makes it adequate.
Dependant on the actual R-Value of the insulation that is already there, you may or may not want to add more insulation when doing the framing. If you choose to add insulation because the existing insulation is not up to R-Value, Use UNFACED insulation and DO NOT add another vapor barrier. Installing another vapor barrier creates an 'envelope' for moisture to get trapped. 2 vapor barriers is actually against building codes.
Framing:
#2.) You could actually use 2x3's since the insulation is already there, but, as a 'newbie', I would advise using all 2x4's. You will want to use pressure treated 2’x4's for the bottom plates (PT on anything that you will attach to concrete). If you feel comfortable with such a tool: Use a 'powder actuated 22 caliber fastening gun'. Use coated 2 ½ “ nails or longer (ceramic ‘coated’ nails have a grey color to them. You need coated nails because the current pressure treated process used for wood contains heavy amounts of copper. This reacts with regular ’bright’ nails and causes rust) Get various levels of power for the firing caps. I suggest #3 & #4. return the boxes you don't use.
Use regular KD grade 2x4 Lumber for the top plates and the studs. Placed 16" OC (On Center). This means what is sounds like. The literal center of each stud (Half of the 1 1/2" will be exactly 16" away from eachother). Make sure that you pick out nice, straight pieces.
If you are unsure of using/renting a nail gun, you can use screws to attach your framing members. If you use screws, get at least 2 ½ “ or longer. I suggest using DECK screws (also for the areas where you attach studs to the bottom PT plate for the same reason as stated above) That length is sufficient, since you are not supporting anything structurally. You are just building ‘partitions’.
Design:
#3.) Do a layout of your basement on paper with the actual measurements of what you want to do with your basement area in relation to walls, closets, rooms, etc.
Materials:
#4.) Use this layout to determine the amount of lumber and other materials you will need.
Remember to get long straight lengths for you top and bottom plates (12’ - 16’)
Method:
#5.) How to build your walls is determined on the age of your home. You see, if you have an older home, then the heights between your concrete floor and your floor joists will be inconsistent. Additionally, there really are no poured-concrete basement floors that are truly level all the way through.
To pre build walls and stand them up and have them fit right, in addition to knowing where to install ‘corners’, corner nailers, etc….is really not in the newbie skill level.
So, I would suggest you just go by the ‘stick-framing’ method. What this is, can be found in #7.)
Note:
#6.) Assuming you have a home 20 years old or less, if you have to build any doorways, it is unnecessary to install actual ‘headers’ on top of the doors, since these are only partition walls. Your house is already built with all the headers and supports that are supposed to be in it. We see this waste of time and lumber a lot in DIY-er basements.
Stick Framing:
#7.) If you are going to put a Sheetrock ceiling in, then it is best to start at your ceiling first and install strapping every 16” OC. This will also give you something to attach any walls that you build, which may run parallel to your floor joists.
After you do that (even if you plan on installing a ‘dropped ceiling’) See the next step:
Walls:
#8) Layout your walls on your floors first by cutting and laying your PT 2x4’s on the floor. Mark where your studs will go FIRST based on your layout needs. Then fasten your bottom plate to the concrete floor. Fire-in your concrete fasteners between each stud. That way, if a nail does not go in all the way, it will not effect your stud placement (which you were smart enough to mark out before -You can also use concrete expandable fasteners for this, like “Red Heads“. Tho this takes A LOT more time)
Marking out the studs for the top plate:
#9) Take, a KD piece of lumber that you will use to make the top plate that will match that bottom plate and place it along side of the now installed PT bottom plate.
Transfer the marked stud lines onto the top plate using a speed square (triangle). Much quicker and accurate this way. It’s how we frame entire houses.
How to level the bottom and top of walls:
#10) Cut a STRAIGHT piece of 2x4 to just over the length of your floor to ceiling height. You will use this as a straight edge to place your level against to mark up where your top plate will be on the ceiling. Just hold the straight 2x4 against one side of the bottom plate. Place a 4’ level or longer level’ against it. (we prefer to use a 6’ level for this) Then line it up to the ceiling and make a mark on the joist or strapping for the matching edge of your top plate.
Do this at one end, of the length of the bottom plate. And then at the other end of the bottom plate. Laying out this way for each length of wall.
Studs:
#11) Take the measurement for each of your studs. Cut them exact, to a 16th of an inch to get the stud to fit tight, but not so tight that it bends or bows. If you shortcut a stud, you can shove a shim into the space to tighten it. (Side point- virtually every piece of lumber has what is called a ‘crown‘. A crown is a slight ‘hump‘. Try to make all the crowns of your studs face one way…usually towards the inside of a room. This way, your walls aren’t wavy)
On all doorways that will have either a door or some kind of casing: Make sure that you 'double' the studs going all around the opening. This gives you about 2 1/2" beyond the door jam to be able to nail your standard 2 1/2 " casing to.
Last: As you go along, you can check your walls and studs periodically for alignment using your levels, framing square, eyeball, tape measure and even a string stretched tight to make sure a wall is straight.
:thumbsup:
GOOD LUCK!