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Discussion Starter · #1 ·
Here is a question-
how would you put block on top of concrete poured foundation?

I am planning on a home project- the lot is sloped left to right and front to back

rancher with slab on grade floor

front right finish floor is 0’
rear right finish floor is 5’ above existing grade
front left is 4’-6” above existing grade
rear left is 11’ above existing grade

i plan on bringing the grade up on the outside of the foundation all around but I won’t be able to make it all up-
i am pricing block foundation walls and the house walls are architectural block - I am worried about backfilling the inside with 11’ of fill so I am now thinking a poured foundation with block on top for the walls of the house-

the foundation will be “covered” with decks so not fully in view so it would have been regular grey block transitioning to architectural anyway so concrete to block is the same thought

i am just wondering thoughts on strength for the back fill and connection details? Just flashing and vertical exposed rebar for the starter course?
 

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Hammered Thumb
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Pick one. Either poured or CMU, they both work to retain the surrounding grade. Your region will have a predominant one for the skills, labor, and costs present in that area. If you are 11' above grade, you build a basement, you don't fill. In the north with deep foundations, it's not even a decision to make, basement it is. In the south, you would build at minimum a partial basement and/or crawlspace to eliminate the fill, and if you don't want a basement with an interior stair, you have outside access storage.

The architectural block for the house is a very unique choice, again, stick to what is common in your area. If your area has block houses, they are probably smooth CMU with stucco finish.
 

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Discussion Starter · #3 ·
The house will be slab on grade- no basement and no crawl space. Several factors here but mainly cost, I don’t want to pay for 2 floors (basement concrete and upper wood framed) and there are large rocks that can not be removed

architectural block is a unique decision.

the original thought was regular cmu grey block up to finish floor then architectural block for the home- the end wall (gable) will be 12’ wall plus gable so roughly 22’ of wall plus the gable(masonry). I thought poured foundation would be faster and possibly stronger then cmu?
in Our area (maryland) most foundations are poured because of time but I also have a skilled mason who could do block
 

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Hammered Thumb
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You can only design a house for it's specific site. It sounds like you have a house plan and are trying to fit it on a site with characteristics that do not match your house plan. If your first floor is going to be 11' above grade, you do not do slab on grade. If cost is a factor (as well as long-term success) you do not want to fill 11'. In Maryland, you need a deeper foundation anyway. Dig a crawlspace at the 0' elevation, as long as that spoils is clayey you can use some of that to fill in the 11' for a uniform 7 block high crawl. If rocks/ledge are present, you design around them or incorporate them.
 

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Discussion Starter · #5 ·
I understand houses being designed per site limits

compacted fill is cheaper then cut/fill, compacted fill, concrete, and wood flooring above- especially with current pricing

I am pricing/ considering all at this point

so is concrete or cmu foundation preferred for 11’ of fill?

it isn’t 11’ total. The site slopes left right and front back with the garage on the end at 0
 

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retired framer
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I understand houses being designed per site limits

compacted fill is cheaper then cut/fill, compacted fill, concrete, and wood flooring above- especially with current pricing

I am pricing/ considering all at this point

so is concrete or cmu foundation preferred for 11’ of fill?

it isn’t 11’ total. The site slopes left right and front back with the garage on the end at 0
11ft high plus what ever you need for frost protection, compacted fill insides, sounds like you need a designed retaining wall as a foundation.
 

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Actually when you look at the cost of things the additional space you gain in a basement is very cheap for square foot especially if you don't finish it. In your case you would almost be free and putting slab on grade above that much fill would definitely be asking for problems!
 
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