Concrete vs. Cinder block

[banjopkr]

Hi,
I am planning a barn and I am going to do a second level that is backed into a hillside. I want to build a retaining wall that will also be a foundation for that end of the barn. The wall will be 32'x 10' with a 5' footing. I have been considering a both concrete and cinder block filled with concrete.
In running the numbers on cost cinder block is the most economical. I am not sure about the strength of block compared to concrete.
Anybody have any experience with this or comments.

 

[dooleysm]

As far as I know, they are both similar enough to not matter. We poured all our walls/footers because we had access to forms and knew how to use them. We didn't know how to lay block.

So, for us it boiled down to us having more time than money, and going with the cheapest option.

I like the look of cinderblock alot better than poured walls.

If your building is going to be insulated, I'd recommend using ICF's, like Reward Wall or other name brands.

 

[drm]

The concrete will be significantly stronger than block. The compressive strength of standard batch plant concrete is in the area of 4,000 psi. Standard block can be as low as 1,250 psi. Cinder block is even lower. Special block with provisions for reinforcing may be as high as 2,500 psi.

More important is providing the proper reinforcing for the walls. This includes dowels and reinforcing in the footing. 10 feet is on heck of a retaining wall. Have it designed by a professional engineer.

...Derek

 

[flusher]

IRRC, around here any retaining wall higher than 4 feet has to be engineered in order to get the building permit.

For a retaining wall 10' high, I'm guessing that you'll have to have some type of horizontal or angled pilings driven into the hillside to help stabilize the soil and keep the wall from eventually bulging.

 

[Matt_W]

It was my understanding that cinder block is more pourous than concrete. I have poured concrete walls for my full basement and have had no water problems.

 

[Birdhunter1]

Cinder block baseemnt walls are very prone to leaking water, properly poured and seaed concrete is not near as prone.

Cinder block contruction doesn't use rebar or wire mesh or anything, the mortar is mied on site and layed on site.
Have you ever dropped a cinder block off the top of a wall or shot it with a high powered rifle? Busts apart every time.

Ever do the same with a chuck of poured concrete? It don't bust most of the time.

 

[Farwell]

I have both concrete and cinder block walls. My cinder block walls weep water where my concrete walls do not. Both walls are coated with sealer on the soil side. Concrete is more expensive, requires forms and more reinforcement but over time I think that concrete is the better investment.
IMO
Farwell

 

[SPIKER]

actual retaining walls need to be checked out and made using dead man back into the hillside, someone mentioned this and that they should / NEED to be gone over by a real enginer5s even if there are NO codes in you're araea still need to have em built RIGHT the first time.

there is a 3rd option, there are concrete retainging blocks MADE for this use, and can be dry stacked quite high with propre back filling afterwards and the proper retension webbing back into the hillside they are a great option cheaper than poured but higher than block but also 100 times better.
they have to ne crane set is biggest pribkem

mark m

 

[CurlyDave]

A concrete wall will be much stronger.

A 10' retaining wall needs to be designed by an engineer, as others have said.

You may need to key this wall.

In order to build the wall you are going to need to excavate behind its final location. The excavation should be "benched" or stepped so that when you are backfilling, the fill rests on a level surface, it should not be placed into a wedge-shaped space.

Proper drainage behind the wall is important, both to prevent water seepage, and for strength. If the wall is drained, it only has to resist the force of the drain rock fill behind it, if it is not drained it must resist the force of the fill plus the force of the water.

In general, water exerts a higher force than the fill.

 

[bugstruck]

Needs to be engineered and properly drained as others have stated. Several ways for the engineer to attack it though. Over that 32' span in a foundation environment, I prefer solutions that take advantage of the cross walls first by spreading the loads to the ends and perhaps a center gut/shear wall if you can. Now if you can't get there that way (I think an engineer could), your into a true retaining wall design. 10' really is allot of dirt.

That wall can be engineered with block, but your still going to have enough concrete in the way of grout, cap beams, pilasters, and the like that you'd be better with all concrete IMO. With block you need rebar and horizontal joint reinforcement too, so the steel component is going to occur regardless of the other material decisions.

If the backfill was more in the <8' range, an all reinforced block solution would be rather more attractive, but still not necessarily preferred.