Framing A Finished Basement

Adding to the living space of a home by finishing the basement is a favorite DIY project. Framing the walls can be a major stumbling block because basement floors are not usually level although they may appear to be from the naked eye. If you build the frame on the floor and attempt to stand it up you may find it will not fit between the floor and the floor joist. Or it may fit in some places and be too tight in others. Do not despair, anyone that has framed a finished basement has experience this dilemma. There is an easy solution.

Building the stud walls for framing a finished basement can be approached in two ways. Each stud wall can be built short (only from the floor to lowest ceiling joist) and use shims between the top plate of the 2x4 wall and the joist after you stand the walls up. Another approach is to build the basement wall in place, meaning that once the floor sill and upper plate is in place, install the studs one at a time, cutting them to the distance between the floor sole plate (the bottom 2x4) and the sealing plate that is attached to the floor joist. This techniques works well and insure that you have a rigged wall. The trick here is to insure that you have the sole plate and the ceiling plate are exactly aligned, one over the other. This can be done by using a plumb bob or a 2 x 4 with a level attached to it and placed against the sill and ceiling plate.     

The sole plate should be CCA treated lumber. That way, it won’t be affected by any moisture that could leech up through the concrete floor. The rest of the wall (the upright 2X4’s and the top plate) are standard kiln dried dimension lumber. Rather than using 2X4s to construct the stud wall 2 X 3s are often used for basement walls as basement walls are not usually structural walls (walls that carry a load on top). The structural walls or support beams are already in place. A 2x3 stud wall is cheaper to construct by about 20%.

The top plate is usually nailed to the joists above. This is no problem where the wall is perpendicular to the joists, but if the wall is parallel to the joists cut a 2X4 block to fit between the joists above the wall location. Nail the blocks between the joists every 24 inches. The top plate is nailed to the blocks. Be sure to plumb the walls before nailing.

Fasten the sole plate to the concrete floor with construction adhesive on the bottom before you stand the wall. Once the wall is plumb, you can drive nails into the concrete with a Ramset. You can rent one from your local rental yard for a few dollars a day. Drive a nail at every other stud space and as close as possible to every door stud.

The basement ceiling can be attached directly to the floor joist or you can install strapping to the joist to attach the ceiling sheetrock. I prefer the strapping because it gives a solid base for attaching the ceiling sheetrock and will be more resistant to movement.

Finishing a basement is a straight forward task that is within the capability of most DIY homeowners. A finished basement can add a great deal of living space to any home. Now that you have the stud walls up it’s time for the electric, plumbing (if any) and insulation.

Insulating Finished Basements

Building a Floor On Top of Concrete

Painting Basement Concrete Walls