New to the forum and hoping for some advice. Looking to add a roughly 350 square foot addition to my 80 year old house and add a garage behind the addition. The current basement is block and stays dry but ceilings are pretty low. It has some waterproofing in place and a sump pump that would be about 15 feet from the addition.
My goal is to tie the current unfinished part into the new part with the new part being a few feet deeper so ceiling height can be high enough to have some finished space. The new finished space would then tie into the old house on one side and the garage slab would back up to it on the other. I considered trying a basement under the garage also for more room but everything I read was it was not cost effective on a lot with little to no grade.
I plan to do a lot of the above grade work myself but sub out the concrete work. Do ICF walls makes sense cost wise? Other better options? If I want the opening to the new section to be roughly 4 feet what type of header do I need for the old block (if any)? Other ideas or concerns that I should bring up to the concrete guys as I get started. Still early stages.
Thanks to anyone for their input!
Ward
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Replies
Header requirements depend on what is over the open space. (that is now resting on the basement block wall)
It also sounds like you are planning to excavate under the footer of an existing basement wall. (or right next to it) The footer needs to stay on undisturbed soil.
https://www.google.com/search?q=Underpinning+or+Benching
If your sump pump ever runs, there may be a perimeter drain outside the footer (or just over it) you will want to tie these drains into similar for your addition (and move the sump pump)
I've done a couple of ICF basements. I think they make sense financially if you do the labor yourself. That said, they aren't as simple as they look. You need solid construction experience to make them work out. And as Uncle Mike says, you need to be careful around the existing foundation.
FYI: https://www.finehomebuilding.com/2005/05/01/a-fast-foundation-for-an-addition