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Default Adding a basement to an existing house?


"JLagg" wrote in message
ups.com...

BobK207 wrote:
JLagg wrote:

(snip)
Thanks for the input folks. I live in Michigan around Battle creek.
There are a few places around me that have basements even walkout
basements. A neighbor actually got under his house and pulled out the
dirt with a 5 gal bucket! took a while for that one. Also would it be
better to use the cinder blocks or actually using forms or is there
really a choice.

Hey, I thought I was the only Battle Creek person around here!

Before you expend any money on design work or start digging, check your
water table level. When I was shopping for houses here a couple years ago,
most of the basements had a musty smell, and the place I ended up buying has
a slightly damp basement, requiring me to run a dehumidifier much of the
year down there. This area is mainly a thin layer of dirt over old sand
dunes. (Look where TopKut meat place used to be, on Beadle Lake Road, for a
good example, or the dirt-selling place on Verona, just east of Raymond.) It
is also rather swampy, as may be expected with all the rivers and creeks and
lakes around here.

I dug out my topo maps, and went to the township office and got a copy of
the flood plain map. Near as I can figure, the water table is about 3 feet
under my basement slab. (And I'm in a raised ranch, on one of the higher
lots in the subdivision.) A house I looked at a couple hundred yards away
through the woods, in the next subdivision over, I think the basement floor
was right at the water table level. During that open house, realtor had all
the doors and windows open, and it still stunk like an old cabin. (Damn
shame, because it was otherwise a very cool house.)

I'd call whoever drilled your well, and ask them. Given the address, they
could probably tell you pretty closely what the water table is in the area.
There may be a reason your place was built over a crawl.

Assuming the water table allows it, the best way to do it depends on the lot
and how the house is built. I've seen several houses in BC with dug-out
basements, and it is usually hand dug, and smaller than the original
foundation, with a mudded-over shelf between the new walls and the original
foundation. Doesn't make for a real useful space. If there is good access, a
house mover could support the place on needle beams and external cribbing,
and jack it a foot or so, and they could carefully excavate from one end by
cutting a trench and using a mini-backhoe on a Bobcat, plus a lot of hand
work. If there is clear space on the lot to move the house out of the way,
that would make the digging much easier. Either option means moving out for
awhile- your stuff can stay, but insurance and utilities won't allow people
in a jacked-up house. But you definitely want to crunch the numbers to see
if it makes financial sense- don't figure on it adding more than 20 or 30 k
to the value of the place. And unless you are in a position to pay for it
out of pocket, the mortgage folks would want to see real good added-value
numbers and real engineering drawings. Almost all the modern basements I
have seen around here are poured concrete, but it could be whatever is
cheapest and easiest. Reinforced concrete probably stands up to hydrostatic
pressure better than block, unless you reinforced the heck out of it.
Attached garages and fireplace chimney stacks complicate things, as does
figuring out where to add a stairwell in the house. Basements with
outside-only entrances aren't a big perceived added value to most buyers.

With the number of houses on the market here locally, and the
still-relatively-low interest rate, moving may be cheaper, unless you simply
have to keep that house.

aem sends....