# Split face block foundation design question



## DRHomeDesign (Nov 16, 2021)

I'm looking for input on how best to build a foundation wall with split face stretcher block with L block for a slab on grade application. I've attached a sketch of what I need, but here's a little more description.

Frame wall will set on edge of L block with Zipboard and steel R panel.

My question is how to cover the smooth L block face (8") and attach the bottom of the R panel? Is there a 1/2”x1" spacer that could be secured to the foundation block and allow for screwing the bottom of the R panel?

Any input would be appreciated!


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## Fourthgeneration (Jul 25, 2021)

Your detail doesn't meet current Nationwide energy specs.......

Two wythes (layers) of masonry with 2-3 inch of blue board type insulation in cavity.... 4 rock face CMUs veneered over air cavity (1") foam, damp-proofing, 6" Cmus? grouted with ties on 16' centers Vertical & horizontal.....

2" x 6" or 8" treated sole plate over veneer and cavity, metal tornado strap anchors in grout, nail off to studs. most poured in inside block wythe.

Most areas, a full high rock face block with a half high 4" CMU for SOG bearing, would be cheaper/ faster then an L block, back


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## cdkyle (Jul 12, 2009)

Looks OK to me, as long as the split face are 8" block that have vertical rebar out of the footing, then dowell/tie into the slab. 
8" Block should be filled with concrete and set up before sand fill. Then anchor bolts for the framing bottom plate.


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## cdkyle (Jul 12, 2009)

16" Minimum spacing on the vertical reinforcing. Fill all blocks with concrete.


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## wallmaxx (Jun 18, 2007)

I haven't seen a block foundation since Clarksville, TN in 2005. I tried to reproduce your sketch to see if I could better understand how it's done in your area. If I got something wrong, let me know.


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## Fourthgeneration (Jul 25, 2021)

Most Zones 4" wall won't meet R values required by national E-Code with out insulated sheathing, or special sawn studs.

You need a vapour barrier under the sill plate and anywhere concrete touches wood products.

I'd damp-proof all below grade masonry on perimeter, 10 mil+ vapour barrier under SOG taped around penetrations.

I'd eliminate the L shape unit, and pour the edge of the slab 8" thick for add floor and structural integrity.... at a tiny cost of concrete, and cheaper block wall assembly
.

In general I'd build with 2X 6" wall studs at 24" vertical centers and 5/8' rock as far warmer and cooler & stronger, then your 4" wide detail, move the sheathing line on the plan OUTWARD 2" to avoid any inside rooms being Too small.....

Upgrading the sheathing to a thicker version improves the flatness and nailholding of the exterior siding for a few dollar a foot of perimeter.
Most 7/16" OSB will fail an air test.......


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