Found a hole in the corner of window sill/ground (soil)/Foundation....what do I seal it with - soil? Cement? Silicone caulk, cement caulk...?

 

Your description is sketchy at best. Is it the window sill, foundation, base of the wall? Maybe you could post a couple of pictures and post on a site such as photobucket.com and give us the urls

 

Sorry if I wasn't clear.
This is a basement window and the bottom of the window is level with the soil. The hole is in the corner of the window and it is where the window corner, soil and foundation meet.
I'll take a picture tomorrow and will post it.

 

OK, here it is.
http://waltham.smugmug.com/photos/191520073-L.jpg

Also, can I take this opportunity and ask how to fix these window sills (similar windows)? If I take those sills out, what's underneath them, is it wood or stone/concrete? If concrete, how does the sill connected to it? Is there something that I can cover these sill with, like vinyl?

http://waltham.smugmug.com/photos/191520214-L.jpg

http://waltham.smugmug.com/photos/191520366-L.jpg

Thanks!!

 

Looks to me like the wood has rotted. Quick fix would be to stuff it with a chunk of wood that will fill most of the hole then caulk the gaps. Permanent fix would be to remove the rotted frames and replace with pressure treated wood then wrap them with aluminium. The framing may be bolted into the concrete or may just be a friction fit. You will see when you attempt to remove them. Someone who wraps windows for a living would be able to do it. Say a siding company. As long as they are this close to the dirt they will continue to draw moisture and rot. They make a vinyl the same thickness as wood now. It is a tad bit expensive but would solve both the rotting wood and would not need wrapped. Check with your local lumberyard for solid vinyl lumber availability and cost. Also might be good idea to check the price of a vinyl window large enough to fill the hole up to the concrete. then that would do the job in one shot without 2 steps. Price will probably dictate your choice.

 

Thanks!!

Pardon my ignorance, but do lumber yards also sell vinyl, or shall I look for a vinyl sill somewhere else?

 

Most better lumber yards and millworks will sell a retrofit sill made of an impervious wood/glue compound or extruded plastic(my preference). They have the exact profile of the one you will take out and won't rot in time. Likewise brick mold comes in extruded plastic at the home centers.

 

...and for goodness sakes, keep the dirt away from the window. Hopefully you will eventually dig out that window well and put in some gravel or something, keeping it a few inches below the sill so that the wood can dry out after a rain.

 

Hmmm....I never thought about that. Thanks for the idea.
The only problem of course is that here in Boston no matter what I do, this window will be burried under snow for many months :-)