Is a bond beam required for block wall infill?

[rosyucf]

I've closed in my existing car port (there is an existing roof and support structure unaffected by the enclosure). A portion of the area I'm closing in is concrete block infill. I blocked in the area without a permit and the building dept is now telling me I must have a bond beam at the top of the block walls. One portion of the wall had existing 8x16" columns on each end and an existing 8x16" poured concrete beam across the top. I just blocked right up to the top beam and to the columns on the side resulting in approximately 10'w x 7'h of block infill. Pouring a bond beam would be very difficult and I don't think's it's necessary.
Is there a code reference that requires me to pour a bond beam in this circumstance or one that exepmpts me from pouring a bond beam across the top of the infill?
I live in South FL in a High Velocity Zone.

 

[concretemasonry]

You had a complying car port before you started.

The new codes, especially in the high wind areas of Florida are based on experience and past performance.

When you added walls to the car port, you added an area of increased wall exposure to the wind.

You now have a enclosure that has walls that will pick up additional wind and that must be designed according to the new standards.

An 8' high block wall in that area with no lateral support at the top is bad and dangerous and non-complying unless it is designed as catilever (which it probably was probably not designed for) since you did not have a permit. When you attach it to an existing structure (the car port) that was not designed for the new loads, you make the complying bracing structure out of compliance and probably inadequate.

I would suggest you work with the code authorities, especially since you tried to circumvent the code with the start of the project. After going through several hundred hurricane damaged/destroyed homes, I have seen many supposedly minor changes that resulted in major damage and personal injuries.

There is probably a easy, but troublesome, method to salvage the work you have done. Just work with the code people since they have a standard they are required to uphold. Just because it does not seem necessary to a mechanical person, someone with more structural experience has deemed it to be a problem for the future owners.

You are lucky it was not attached to your present home, since then you could possiblt fall under the projectile requirements also.

Dick

 

[jike]

I definitely agree with Dick's comments! The recent changes in the code are because of the many failures that happened.

How is the wall fastened to the the existing structure? Does the existing structure have enough capacity to resist the additional load transfered to it by the wall?

 

[UcfSE]

Is there a significance to the last 3 letters of your screen name, rosyucf?

 

[rosyucf]

Thanks for the comments.

My surface area of exposure to the wind for the existing structure has not increased due to the change in location of the exterior walls. I now have also decreased the surface area of the roof exposed to uplift. I believe I could calculate the only additional surface areas exposed to wind and show that it supports itself against the wind. The exising structure in not necessarily supporting more wind surface area.

The inspector is asking for the bond beam becuase he is used to seeing them in new construction. My neighborhood is full of similar homes that closed in their carports in many different ways, none of which seemed to utilize a bond beam. They seemed to have performed well over the years since they are still standing. Most of the homes are 50-60 years old with little or no recent changes (last 10 years). The new remodeling/renovating residential code does not require the bond beam. I do not doubt the benefit of the bond beam but I question if it is required in all circumstances; especially where there is not a feasible approach to installing the bond beam and a concrete beam exists atop the wall.

I'm looking for more experience where someone may have encountered a similar situation and determined the necessity of the bond beam and if their research has determined if the code requires the bond beam atop an infill block wall. I've seen occurances where in multistory construction they do not pour a bond beam for infill walls.

Go Knights!!! (We lost our "Golden".)