I would like to use the surface bonded block technique described by Paul Hanke in Foundations & Concrete Work book and article published by Taunton. The building inspector is very hesitant to approve anything that isn’t specifically described in the 2006 IRC, and he can’t find specific reference. References in IRC R606.8 Stack Bond, page 181 and other R606 hollow masonry don’t seem to satisfy him in regard to surface bonding technique. If anyone has any reference to specific lateral and tensile strenghths, approved permits, engineering information, or where I can reference the USDA Information booklet No. 374 I would really appreciate hearing from you.
My application is for a 1 1/2 story log home, using a 8″ thick x 24″ wide footing below frostline (24″) then 4 courses of block turned 90* to provide a 16″ wide bearing surface with a 4″ slab on grade (radiant heat) tied into and poured over the block. Rebar will be used throughout according to code. I plan to insulate the slab and block as described in above referenced book, “A Slab-On-Grade Foundation for Cold Climates”. Would it be structurally unsound to place the insulation board directly over the block (filled or hollow, with wire grid & block filler mesh for support) and insulate the top 6″ or so of the outside to accomplish insulating only the pad? I plan to install a perimeter drain. I’d like to use block to reduce costs and simplify construction, rather than poured grade beam or monolithic slab.
Originally I researched the rubble trench techinque; but upon classifying the soils (silt loam, ML-CL or similar) at 1500 psf or less, and without having the site soil strengths calculated by an engineer, plus negative input from the building inspector I decided to not pursue that route. After conferring with a geotechinical engineer he implied that a rubble trench probably would work but the costs of the engineering and extra material would probably supercede the costs of block.
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http://www.google.com/search?hl=en&safe=offclient=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&hs=UHvq=surface+bonded+masonry&btnG=Search
I started your search for you. I know that makers of stack N bond products have tests and documents showing that they are able to meet tensile and load standards under certain conditions. so you want to find install specs and material data sheets to study. That may satisfy the inspctator
BUT
every surface bonded wall I have seen was in a sorry state and needing replacement - possible a part of the reason why I saw them - they needed somebody to do the work.
But as I understand your description, you would stack these with a 90° rotation to the normal layout, something I have never seen but that would give more lateral strength.
To get full strength on a surface bnded system, you need to apply to both sides of the wall. IMO,too many walls get the treatment on the outside only, with owner DIY thinking they will get around the inside later, but one side only is less than half as strong - it gives a wall with only about 30% as much tensile strength or less.
Clean surfaces, and proper curing are highly important as well. I find the material a good way to add strength and water resistance to a normally laid up wall and it can be a way to add the stucco look instead of ugly block but I find it as easy to lay with mortar typically as to do this kind of system.
If you are infilling under a slab, and not keeping an open crawlspace inside these walls, the inspector should have no problems, as the lateral force is offset by the resistence of the material insiode the foundation.
not sure if I understand the insulation Q. Maybe I'm just too tired tonight.
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http://www.drystacked.com/standards.html
This and the links in it may have what you need for him.
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!