Can you show us a picture?

8 and 10 inch what??? ... diameter??? ... not feet right ... your talking width not height is the ?????

the issue is how much root damage you will do.. and how will it impact the tree ...

a tree is 2 to 3 time larger underground.. than you see above ... in a flat pancake shape.. usually most in the first foot or two of soil ...

so any soil grading ... footing/foundation work .... and/or heavy equipment can impact the roots.. and if you harm the roots.. you harm the tree ..

soooo.. the further you can be.. the better off it is ..

pix will really help .. and do you have acreage and alternatives ... and what will the floor be.. etc .. all you mention is footings ... where are you.. big city name... and what does footings mean where you are ... are we talking the 32 inch footing in a ground freeze area ... and what will the actual floor be ... etc ... give us some more facts ...

tree time is counted in decades .. even if you do damage to the roots.. it could be 5 or 10 years or longer.. before you see the result ... if i were limited to location.. i might include a couple new babe oaks in the build budget ... and plant them and get them going.. so if in a decade or so.. the old ones have to go ... you will have replacements.. cant ever have enough trees on the property ...

ken

Sorry, Ken, 8 and 10 inch diameter. And yes, I'm worrying about root damage.

Location: Northern NY (Eastern Adirondacks/Champlain Valley). Very hilly, forested land. I'll try to get a better photo, but I'm not there right now. The tree in question is at the right edge of the first picture.

North side of house showing location of garage.

View looking East of the rock wall which will be removed, from the upper deck seen in the first picture.

Here is a drawing of my idea: a 24 x 24 foot deck supported on the East (top of drawing) by the existing driveway surface and on the west by a N-S beam (not shown) which, in turn, is supported by new supporting column and the foundation of the house (on the right. Retaining walls with foundations will be added as needed.

Where are you planning to put the garage?

Where the 24x24 deck is.

Where the two story deck now stands?

The two story deck is not shown In the third image (drawing), The garage deck (the gray square) would be immediately to the left of the building. This is just west of the entrance deck. Both decks are shown in the first photo. The issue is the closeness of the trees which are to the left of that deck and where to put the foundation.

So are you saying that embankment may need to be pushed out closer to the tree?

tj

No, the rocks would be removed and a concrete retaining wall put in behind where the rocks are now. My concern is that the footing for that retaining wall might kill the tree.

Well, I've decided to not put the garage there, but go back to Plan B, which is to put a long, narrow garage between two groves of trees. (Plan A was to excavate a place in the side of the hill, but it was vetoed by DW because it would entail cutting down too many trees.) The link below is my thread about Plan A.

https://www.houzz.com/discussions/6140826/new-garage-in-the-woods

Question to Houzz: is this the best way to link to another discussion - that is, to post the URL of that post?

that is a very common way to link posts ....and i have nothing to do with houzz