If doing a backyard block walls (some retaining) that will be finished with stucco, would doing them with ICF be a cost effective option vs. CMU? This would be during an ICF home wall build so the forms and concrete pumpers are already there. CMU would require different trades and additional hauling of the blocks.

In Mid-Atlantic states, vanilla CMU is about $4 - $5 per sqft

If you are going to stucco it, then perhaps just use SCIPs.

Or sand cast stone+concrete tilt-up (very nice looking).
www.thecastleproject.net/tilt-up_stone/page/3/

In my local area, 8"x8"x16" CMU blocks are ~$1.50 delivered price. Cement and sand is extra, but I'll throw out $0.50 per block which will more than cover the cost of mortar. Average laying costs here are ~$1.25 per block (I was quoted anywhere from $0.90 to $1.35 per block). I paid roughly $1.00 per block for my garage foundation blocks. A retaining wall should be relatively easy and fast job for most block layers.

That's $1.50 + $0.50 + $1.25 or $3.25 per block installed. A block covers 8"x16"/144 or 0.89 sq ft. $3.25/0.89 sq ft = $3.65 per sq. ft. ICF will cost at least 3 to 4 times that much. Depending on the height of the retaining wall and amount and type of backfill, you may need to fill the cores with concrete and throw in some rebar. Even doing that the cost of ICF will likely be twice the cost of CMU. Also, with CMU is relatively easy to apply a cement parge coating or cement based stucco.

Another option is to just dry stack CMU blocks and apply surface bonding cement to bond them together and provide the finished surface. The surface bonding cement can be colored as desired. Search google or youtube for [surface bonding cement] to get some ideas. Any mason should be able to do this job relatively inexpensively.

Posted By arkie6 on 28 Sep 2013 12:00 PM
In my local area, 8"x8"x16" CMU blocks are ~$1.50 delivered price. Cement and sand is extra, but I'll throw out $0.50 per block which will more than cover the cost of mortar. Average laying costs here are ~$1.25 per block (I was quoted anywhere from $0.90 to $1.35 per block). I paid roughly $1.00 per block for my garage foundation blocks. A retaining wall should be relatively easy and fast job for most block layers.

That's $1.50 + $0.50 + $1.25 or $3.25 per block installed. A block covers 8"x16"/144 or 0.89 sq ft. $3.25/0.89 sq ft = $3.65 per sq. ft. ICF will cost at least 3 to 4 times that much. Depending on the height of the retaining wall and amount and type of backfill, you may need to fill the cores with concrete and throw in some rebar. Even doing that the cost of ICF will likely be twice the cost of CMU. Also, with CMU is relatively easy to apply a cement parge coating or cement based stucco.

Out here in the desert SW the CMU walls are popular but they pose certain problems that people in non-desert areas don't realize. They are a HAVEN for scorpions. Since CMU block walls are hollow inside and the mortar joints don't completely seal the wall in all areas, scorpions LOVE living inside CMU walls. At night hundreds of them come out from the CMU fence walls.

I don't want to create a haven for scorpions so I would want to completely fill the CMU wall with concrete, this would drive up the costs. I am also NOT a fan of hollow block walls for strength reasons. I've seen CMU fence walls topple over from high winds. You can push on a CMU fence wall and watch it move. A CMU wall is no match for a car, many times out in Phx a car going just 10-15 MPH hits a CMU fence wall and the entire wall collapses.

So to achieve my goals of NOT leaving a hollow masonry cavity for scorpions and centipedes to reside in and for strength reasons I would have to fill the CMU walls with concrete, which would drive up the costs.

With that being said, would it still be cheaper with CMU if I had to fill them all with concrete, top to bottom?

Posted By jonr on 28 Sep 2013 09:49 AM
If you are going to stucco it, then perhaps just use SCIPs. Or sand cast stone+concrete tilt-up (very nice looking). www.thecastleproject.net/tilt-up_stone/page/3/

No shotcrete available out in that area. Very expensive to bring in the supplies, equipment and the know-how crew to do it.

Also the wall has to be a very smooth stucco finish, like the home wall. The walls other purpose is to act as a "snake wall" which is something they do out in the SW desert sometimes. CMU walls that are unfinished don't qualify because the mortar joints on the CMU acts as a gripping area for vipers. Hence the reason for smooth stucco.

No shotcrete available out in that area.

Shotcrete is just concrete (with small aggregate) and it can be applied with a small hand mortar sprayer.

Online concrete calculators show approximately 0.012 cubic yards of concrete per square foot of wall to fill 8" blocks. At ~$100/cubic yard for standard concrete, the material cost to completely fill the blocks would be ~$1.20 per sq. ft. That would be a fairly easy pour if you already had the people and equipment onsite to pour the ICF walls. This would be an ideal application for the dry stacked blocks with surface bonding cement applied to give the smooth finish of stucco.

I was told the cost of a CMU wall is around $11 per sqft of wall space; parts and labor.

This is 2013 costs. CMU COST CALCULATOR

Who told you it costs $11/sq ft? A local contractor or that online calculator? Sometimes, you have to get off the computer and actually talk to people. I don't know why I reply to your posts. It is always an endless circle jerk. If you already have the answer, why did you ask the question?

Posted By arkie6 on 29 Sep 2013 12:20 PM
Who told you it costs $11/sq ft? A local contractor or that online calculator?

I talked to a few contractors and nobody came in at $5 per sqft. I was quoted $11 - $15 per wall sqft.

Nobody I talked to came in at $5 per sqft. They laughed when I told them $5 per sqft. They said that one couldn't even get the parts & supplies for that amount.

As far as online calculators go. Besides the one I linked, all the other ones said the same thing. Around $11-$13 per wall sqft for a CMU wall.

BuildingJournal Masonry Block Wall

My original question was legit but I questioned your post where you quoted an amount of $5 sqft. When I called around and talked to contractors, nobody even came close to that amount. I wanted to verify your numbers and if that offends you, I am sorry.

Posted By Lbear on 29 Sep 2013 12:22 AM
I was told the cost of a CMU wall is around $11 per sqft of wall space; parts and labor.

This is 2013 costs. CMU COST CALCULATOR

Where is that in the country? In LA or NE, their costs would probably be 3-4x as much as the rest of the country.

Posted By robinnc on 29 Sep 2013 06:53 PM

Where is that in the country? In LA or NE, their costs would probably be 3-4x as much as the rest of the country.

The $11 per wall sqft area is in Phoenix, Arizona. CMU block walls are everywhere out here.