Cinder block stem wall

[Peter]

I am about to build a cabin to replace one that burned down recently. The location is very remote; I can't get a concrete truck onsite, so I will be using a mixer. I'd like to use cinder blocks on a concrete footing. Any tips on how to go about this? I have the trenches dug out 12" deep, 16" wide. My current thought is to form the trench with a single 2x8 at grade on both sides to minimize concrete waste, then add two rows of blocks with mortar and of course, concrete in the holes.

[Rich]

That's a typical installation for CMU stemwalls - good job. Make sure and pour the vertical rebar into the footing. I've written an article on pouring footings located here (http://www.construction-resource.com/concrete_footing.php).

[Peter]

Thanks for the tip, and for the article. I found it very useful. My next question concerns the vertical rebar. How often do I need to use it to meet UBC code? How should I measure where to place it in the footing so that it will match the holes of the cinder block when I install them? The cinder block installation will likely be a couple weeks later.
thanks,
Peter

[Rich]

From the outside edge of the cmu (and this depends on the overall width of the stemwall) you will go 4" in from either side. This assumes a typical 8"x8"x16" cmu block. From the 4" mark you will go every 4' or multiples of 16". So at the footing edge you will measure 4" from both sides and that will be the corner of the cmu.

Probably the best way to figure it is before you pour the footings put in nails at the centerline of all the stemwalls and after you pour (before it cures) you can use the nails to snap lines in the center of the stemwall and this will be where you place the vertical rebar using the spacing stated above.
Hope that helps.