block or poured foundation ?

[yeldogt]

I'm about to start my rebuild and I had a conversation with my builder and the foundation came up. The architect has a poured foundation on the pre construction plans. I mentioned it and my builder said he actually likes/ prefers block .. but they do poured also ... about the same price.

I'm an old house guy -- this is one of the few new builds that I have done .. so I have little experience with new foundations other than fixing or extending -- and have always used block


I just assumed that a poured foundation was preferred.

 

[mechanix311]

a proper stem wall poured is so much stronger than block. Surprised its the same price as a block stem wall. Plenty of houses with both but concrete is stronger and block looks better.

 

[kbs2244]

Are we talking about a basement?
In a no basement case the only stress in straight down since the foundation is back filled on both side.
With a basement there is the sideways force of the dirt on one side pushing in.

So, with no basement, block is fine and poured may be over kill.
With a basement, block may be problematic depending on local soil conditions.
(There are millions of just fine block walled basements under houses in the US.)
A reinforced poured concrete is much stronger in resisting the sidewise stress of being backfilled on only one side.

Your contractor prefers block because it in much less cost to install.
Basement or not, for the same money reinforced concrete is a hands down winner.
(Make sure they put steel reinforcing in the wall.)

 

[Architorture]

The block really should be a cheaper option. If he wants to so it with block ask him to show you the savings.

 

[yeldogt]

I'm knocking down a fire damaged addition and replacing it with a slightly larger and deeper one -- the old building is block. I guess you would call it a full height basement ... although it will be living space. The addition is built into a bit of a terraced hill.

The foundation is going to be covered in stone.

Only one story on top of the foundation ...

 

[holdover]

I would do poured especially if quoted the same price, In my section of VA poured basements didn't really start for residences till about 1975, commercial before that, after that I never did another block foundation, stronger, less prone to leaking etc etc. either one required a footer, easier to form up than to lay blocks.

 

[drivesitfar]

i'm guessing if its the same costs that the builder is planning on filling the block with cement, but that wasn't noted. i'd almost always go with a poured cement wall with plenty of rebar connecting the entire wall and floor together if possible.

Block might eventually weep or leak through the morter in the joints too which is something i wouldn't want to happen in my basement.

 

[volleyball]

Location and access to concrete guys factor in greatly on price. Since it is going to be living area, poured is much better. And go with 5000 psi for its water intrusion properties, better yet go with the foam blocks. Forms and insulation in one easy package.
Consider 10" block if you think there is any chance there might be a second story in the future or if there is an active load next to it.

 

[yeldogt]

The foundation came up during a discussion about a nearby retaining wall ...

I spoke to the Architect -- poured wall. Some of it is 12" thick where I have a bump out and other parts are 8".

He said because of the site we need some extra reinforcements and larger foundation on one side.