One important ingredient was left out of your original post, Alexander:

Why would you (or most anyone else) want a six-foot wide by fifty-foot long
basement, whether cost effective vs crawl space or not? That is really the
basis of your problem.

Off hand, I'd say, it might be good for coal storage (if you ever have a use
for that much, if any, coal) or a very narrow, indoor lap pool (for lapping
underwater) or maybe a cistern or root cellar . . . but now I'm getting too
practical to be plain silly. Off hand, I'd go with a crawl space, just
because the basement isn't likely to be cost effective regardless of the
likely usefulness.

Jim

"Alexander Galkin" wrote in message
...
I am planning an addition to my 2 story colonial. The addition is actually
extending first floor along the side facing backyard. The addition will be
50 ft long by 6 ft wide. I want to do as much as I can myself leaving to
pro
only that part of the job that I absolutely cannot do or make no sense to
do
myself. I have moderate experience in framing, plumbing, electrical,
insulation, drywalling and have all necessary power tools to do the job. I
do not have any experience in building foundation or putting joist-beam
floor system. I am weighing two options for the addition foundation: crawl
space and full basement. Here I have several questions:

1. While I realize that every project has it many specifics what the
approximate cost would be to excavate hole for the 50 ft x 6X ft addition
foundation, build the foundation walls and slab, backfill and put the
floor
with no subfloor? I line in Central NJ.

2. What's the approximate cost difference of building full basement vs.
crawl space? Frost line in my area is 3 ft so trenches for the footings
must
be dug 3 ft at least.

3. What's the approximate cost and benefits difference of concrete
monolithic vs.cinder blocks foundation? My house (55 years old) foundation
is built using cinder block with I believe no rebar reinforcement.

4. Is it feasible both economically and from time perspective trying to do
some of foundation work myself? Could you advise me if any of the
following
foundation tasks I can do myself or I should forget about them and leave
them to pro:

- building footing forms and put rebar in them

- renting gas powered concrete mixer or get ready mixed concrete and build
footings myself

- building foundation walls using cinder blocks

Is above what I can really do myself or it is not worth it? I have limited
experience with concrete (redoing parts of basement slab after installing
underslab plumbing)


I believe having foundation built and floor put I can take over enlisting
my
Dad's and friend's help to put frame, siding, roof, plumbing, electrical
and
internal finish.

Any comments and advise would be greatly appreciated.