Basements, Attics and Crawl Spaces - Basement Finishing Advice...

After years of putting it off, I am ready to take the plunge. I have replaced old broken basement windows and sealed the 8" poured concrete walls with a concrete sealer. I have already cut and installed a 4x6 egress window so I am good to go there. The space I will be doing isn't huge, about 350 sq. ft, enough for a large bedroom I suppose. I will try and post some pics later tonight.

Here is what I have so far:

The wall for the stairway is already framed. I will be framing 3 walls total. 1 interior wall and 2 against the poured concrete. In an effort to conserve a bit of space and not have such a hard time with electrical later on, I am leaning towards 2x3's.

From what I have gathered thru research, I am planning on adhesing 1/2" foam to the poured concrete walls. (I have seen this stuff used on the exterior foundations in new construction, it's white, can't rememember the manufacturer). From there, I will place the 2x3's directly against the foam. This will help with insulation as well as a moisture barrier, even though the basement is very dry (I did the taped plastic test and got 0% moisture). Then I was planning on running electrical etc. and filling the 2x3's with 3/4 - 1" rigid insulation. Followed by the drywall, being screwed to the 2x3's.

Does this sound ok?

Also, the ceilings are only 7'-0 so I am trying to decide on what to use for the floor. Tile, Stained concrete? I have a large roll of non-stretchable carpet I could use also, I would just have to buy padding to go underneath.

This room will act mainly as a home entertainment type of area for movies etc. but could also be used as a bedroom in the future.

Any ideas and/or suggestions would be appreciated!

Thanks!

You said you will be framing 3 walls (2 against the concrete and one interior wall). What is the fourth wall or is it an odd shaoed room? Is the entire basement conditioned or do you have a semi-conditioned space for utilities? Are you planning to insulate between the semi-conditioned space and the finished space?

If you want a firm surface and insulation, use extruded foam (pink, blue, yellow) and not the cheap expanded foam (white bead-type foam used for coffee cups). Avoid fiberglass if possible.

You seem to be very concrened about the wall insulation and given little thought to the floor surface. The floor temperature is about the same temperature as the lower wall without any insulation.

How much insulation you do on the walls should bepend on the above grade exposure area of the walls and your climate. For a full basement, even in a real cold climate, you need much less insulation than you might think. There may be better places to spend your time and money. Remember - the temperature differential between the soil and the interior is much less than above grade construction and there is NO air infiltration. Every bit of insulation you add costs you any gain you could get during the cooling season. Keep in mind insulating suppliers sell based on steady stae conditions and homes go through a very different dynamic cycle.

You may get some "fluffy" very general advice and sites to look at from the heavy duty posters, but take time to look at the facts. It seems you have already done your research and may know more than generalists.

One common basement wall insulation method is attaching 2x2s to the wall and then use 3/4" rigid foam between the 2x2s. Cut out channels for any electrical and use shallow boxes. Then add a second layer of 3/4" foam. Use plates to protect the electrical runs and cover with sheetrock. Even though the wood does not insulate as well as foam it is adequate for this purpose and not as bad as something like a high heat loss steel stud.

The key to a successful basement finishing project is (1)dryness, (2) light and (3) comfort.

1. You think you have solved the wall leakage and hopefully have drain tile and no possible leakage at the wall/floor joint.

2. Adding a 4x6 window should give you plenty of light for a small space. The downside is the amount of heat loss inherent from a large window area.

3. Since most of your wall area is below grade, your wall insulation is minimized. You should address the 350 sf of uninsulated floor (55 - 60 degrees? in many/most climates). Provide enough air supply AND returns (never enough it seems) to maintain a good feel and maintain air uniformity throughout your home.

Just a few points from a different direction for your check lists.

Dick

2x3's may not give you enough space for electrical boxes, considering the volume requirements are based on size of wire and number of wires, plus other factors.

Here are some pics of the basement. The one wall that is already framed is the one covering the stairway as you can see in the photos. As you can see, we have a new furnace in one of the corner. I was planning on framing this out of the room. The egress window, I still have to finish sealing etc. Anyways, I am still in the beginning stages of prepping the basement before framing. We live in Boise, Idaho, so the winters get pretty cold here.

http://i56.photobucket.com/albums/g194/BoiseLifer/P9080457.jpg

http://i56.photobucket.com/albums/g194/BoiseLifer/P9080458.jpg

http://i56.photobucket.com/albums/g194/BoiseLifer/P9080459.jpg

http://i56.photobucket.com/albums/g194/BoiseLifer/P9080455.jpg

http://i56.photobucket.com/albums/g194/BoiseLifer/P9080456.jpg

Agreed about the electrical problems is a shallow/thin wall.

I used shallow metal boxes for my 2x2 wall (put barrier behind the box just for insurance). The inspector, who seemed quite thorough approved the intallation at the time (10 years ago).

You can't put much in a real shallow box, but if you are just running a string of #12 around a basement for outlets, mine was O.K. My more complicated wiring was in the interior walls and above.

Boiselifer - Don't worry about the Boise winters. We are in the 7,000-8,000 degree range here if I recall correctly. Mother Nature does a wonderful job of moderating the soil temperatures very well. You may be quite dry and not have a thick insulating snow cover. We get only 45 inches per year, but you can often find only a few inches of frozen ground under undistrubed snow. In northern Minnesota, it is common to find no frost under an undistubed heavy covering of early snow (usually off a snowmobile trail).

Dick

Boiselifer -

I just took a quck look at the photos. You certainly have number of heating and electrical items to content with.

On your sliding door -
Make sure you have a means to collect and get rid of any water in the area/well immediately outside the door.

You can easily install segmental retaining wall units to provide a small wall (stright or curved) to fit your landscaping and access requirements. No footing would be needed.

I saw one installation where the remodeler created a "greenhouse" ouside the sliding door by using these block. On top he built a frame and used window sliders of some sort on a slope to create an enclosed garden area that also served as an egress. - Just a thought, but the extra slider is not required unless you want a tropical garden.

You have a fun project ahead of you.

Dick

Thanks Dick, I appreciate your replies.

So, if I go with 2x2 fur strips, what is the best tool to attach them to the poured concrete? This concrete is extremely solid. When I installed the egress, I had to rent a power hammer to get the nails in. Maybe I will just go with 2x4's and batt insulation. Seems like it would make life easier and the loss of space really isn't that substantial as it is a pretty small room anyway.

As far as the floor, would a nice carpet pad below a non-stretchable berber carpet work ok? I would think that would give plenty of insulation.

Yes, I was thinking of making a concrete block, type retaining wall as you are suggesting, just outside the egress.

Any ideas on what to do with the old coal shoot? It is a 22 x 14 rough opening, I suppose I could just stick a custom sized window there. I have a milgard or Pella quoted at around $60 for the window itself. More light for a basement can never be a bad thing.