Empirical design & permits...
is Empirical Design
This is very good news if you want to design in dry-stacked block construction. As long as your building complies with these minimal requirements, then expensive engineering studies may not be required for building permit approval.
Some of the terms you will be looking for are continuous bond beam span openings, bond beams combined with lintels, vertical wall reinforcement, shear walls, and roof framing connection to bond-beam or bolted top plate.
You will have to find out what the minimal requirements are in your region, but the Florida requirements for 100-mph winds are discussed below as a representative example. Even if you are in Florida, you must still contact your permit office to see what building code is in current use, since the code changes from time to time.
One and two family home construction in areas with a basic wind speed of 100-mph or less, shall comply with the following:
Exterior walls shall be not less than 8" thick for a multi-floor
structure, nor less than 6" thick for a
A reinforced bond-beam shall be placed around the perimeter at the
top and bottom of each multi-
Wall area cannot exceed 240-sq. ft. without approved vertical and
horizontal support. If your walls
d. #5 rebar reinforced wall cell grouted with concrete at each corner.
a. #5 rebar reinforced grouted wall cell on each side of all doors and windows.
b. Two #5 rebar in the bond-beam (to meet combined lintel/bond-beam requirements).
c. Two #5 rebar in all foundation footers
d. Header rebar requirements are specified in header tables within the code.
Once again, check your local code for exact requirements. For example, you may not need 2 each #5 rebars in the entire bond-beam, but I did it anyway for added strength. My window and door headers were much taller than required (about 24") but that solved many forming issues and window/door framing issues by making the headers higher than required. The code is only the minimums. You can build beyond the code requirements when you feel the need to do so.
There are also general rules relating to a ratio called the Maximum Span to Width Ratio of Floor and Roof Diaphragms. This simply means the length to width ratio of the floor plan and roof plan. For a wood stick structure this ratio is limited to 2:1, but a block structure can be 5:1. This means that if your floor plan is 40-feet deep, then it could be up to 200-feet wide (5:1 ratio). Of course, you still have the 240-sq. ft. rule to contend with, so a wall this long would need outcroppings or lateral reinforcement to break it into smaller sections for stronger home construction.
As you can see, complying with Empirical design rules is relatively easy with most home designs. Just keep these issues in mind as you plan your home design. This pretty much sums up your requirements to build under the Empirical design rules. As stated earlier, check with your permit office to confirm their current requirements.
If you take with you the "ASTM C-946-91 (change 91 to current version) Standard Practice for Construction of Dry-Stacked, Surface-Bonded Walls" which can be purchased on the Internet, by searching for the title name; you will impress the inspector and establish a better relationship with that office. It also wouldn't hurt to include the Quikrete product data sheet for QuikWall, or any other surface-bonding product you intend to use. These can also be downloaded from the Internet or mailed from the manufacturer. Once again, you will demonstrate to the inspector that you intend to do a competent job, and you will also provide facts, which should help dismiss any early inspector doubts about the process. After all, the inspector is an engineering type, and specifications are what appeal to him/her.
Don't try to cover every detail at this first meeting. It would be helpful to mention that you are seeking reference standards which describe concrete block construction rebar requirements for wall cells, door and window poured headers, and bond-beams.
That's it, bail out of the meeting with these small tasks accomplished. Now you must review the appropriate standards and the application package you received, and then determine any questions you may have about your proposed plans and the code. I'm not suggesting that you have to learn the building code in detail. I am just suggesting that you read through the building code chapters, which apply to your home construction details.
Your next meetings will be informal and hopefully conducted during the morning questions availability time. Most offices make the inspectors available for building permit questions during the first hour of office operations. This gives all builders a time when they can call or visit an inspector for technical questions about their project. For the remainder of the day; the inspectors will be out of the office, unavailable, and conducting inspections. Once again, only ask a few questions during each call. Space your calls a couple of days apart so you don't appear to be a burden to the inspector. Try to limit your questions to topics you can't find in the building code, or to topics you have found, but you still require further clarification. The inspectors will be much more helpful when they realize that you are reading the code.
Electrical & Plumbing
Inspections are typically scheduled when you call an answering machine and request a particular inspection. In my region, if you call before 8AM, Monday through Friday, then the inspection will be conducted on that same day. I usually call the evening before to avoid busy signals. While working on a specific task, when in doubt always make that phone call to the inspector for clarification. It is much better than doing it wrong, failing an inspection, and then having to do it right. I have never failed an inspection to date, but I do my research and ask questions when in doubt.
The State of Florida considers a building permit abandoned if six
months passes without
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