I am looking into purchasing my first home up in the fridged northern NH.  We experience 9000+ heating degree days.  This Home has 2400 sq ft of living space and is insulated through out to decrease drafts.  The previous owner burns through 15 cords of wood a year with an outide boiler and states that the heat loss is due to the basement siting on ledge and the over half of the basment floor is ledge (bedrock).  I would assume that normally, the square footage and age of this home would normally use up 6-8 cord depending on efficiency.  The home owner states that the ledge is like a heat sink and sucks out the warm air... which i understand.  There is no insulation on the foundation and there is water that runs down through an out the basement due to the hill Directly behind and up against the home. The H20 is not the problem with very adecuate drainage... i am certainly concerned about the heat loss.  how do i insulate the basement to lower the BTU load?... all of the plumbing runs through this basement so i do have to heat it, but i also need to ensure that the minimal h20 flow does not freeze for this can lead to problems. 

Can i insulate in between the floor joists to try to keep the heat up stairs on the main floor and the 2nd floor?

I have Considered using a jack hammer on a large piece of equipment, to dig down and around the home, my concern is that this would break apart the existing foundation...

Look forward to your responses... for this forum will lead me to either purchase this home or not...

M

If it was me I would probably put down 6 mil poly, and then spray foam the floor with 2.5 inches. If he has an outside wood stove you already have the hot water. I think you should consider putting radiant heat in the floor then concrete on top. If you heat the basement floor it will make a huge difference.


IMO

Garrett

i assuming that it is a granite field stone foundation? check for exterior wall insulation gaps the easiest would be a slow minmal expanding foam cavity fill or blown in cellulose and insulate the attic extremely well as hot air rises the roof will loose more heat

given its late in the year i would contact a spray foamer and make a appointment for spring after the melt off/ mud season and ask what prep work needs to be done cleaning putting up remesh or chicken wire .. what ever to keep it up in the joists .. what ever and tell them you will DIY and hope to save $ they only need to back in spray and drive out. force motror/sparging in the joints of the stone to try and keep moisture from comin in in the future as we want no problems later. have them foam the walls someeven a inch or 2 will keep er sealed and a thermal barrier attach a expanded metal and cover it in cement(i would use vermiculite/vocanic dust in place of sand keep it light and slight insulate)/shotcrete. dig arround the exterior sparge/mortor 4 foot from the top of the foundation and apply a 2-4 inch foaam board and put a french drain in while your there and seal the foam into keep water/cold away from the wall. total over kill but i do things forever.
shotctete and foam is or atleast sparge? force mortor in the stone seams and cover

or if you want to DIY and dont feel comfortable DIY spray foam attach 3 or 4 inches of ridgid foam between the joists . old home cold floors are terrible but it wakes you up quick

now that you sealed stuff up you need to worry about radon. welcome to old home ownership

I would think that the H2O IS the problem. If I understand it correctly it is running through the basement and taking all the heat with it. Either you need to stop the water at the outside and than insulate the floorslab or you need to construct something over the drainage that can be insulated. If you have the head room, you might be able to put in 3 or so inches of washed drainage stone, than place closed cell foam over it and pour a new slab with or with out hydronic heat. However if you do hydronic heat it is essential that it be separated from the drainage or it will still take a large chunk of the heat.

I have Considered using a jack hammer on a large piece of equipment, to dig down and around the home, my concern is that this would break apart the existing foundation...

Hi,
That was also my concern but i think this could be done right after this time..