Just received a call from a potential customer wishing to have a 24x32 detached garage foundation laid up with 6 inch block. Will 6 inch be suitable/structurally sound? I have never seen plans using 6's and typically use 8's. Any help would be greatly appreciated. :thumbsup:
fortstowe
Only difference is you need more reinforceing with 6" . Dura-wall evry other course, and instead of re-bar pined to footing evry 4' like the 8" are id pin it every 32" and grout,, even if its only 3 courses ( 2' ), if any taller why not throw a bom ( bond ) beam in there ,, cant hurt:thumbsup:
Dik -
That is a little much for reinforcement. Bad engineer, bad code or bad inspection. Almost any code will allow unreinforced block for garage foundation/stem wall. A bond beam makes sense since it gives you a chance to hold down the flimsy wood frame garage. From a practical standpoint reinforce and fill the cores where you have an anchor bolt.
A comparison with some good construction - They may have 32" or 48" reinforcement spacing for the lower one or two floors on a 20 story building. After that, it is less. Why go crazy on a garage?
Poor engineering is one of the reasons for the lack of masonry. Throw in an uneducated inspector in and you have a mess and less masonry.
That is a little much for reinforcement. Bad engineer, bad code or bad inspection. Almost any code will allow unreinforced block for garage foundation/stem wall. A bond beam makes sense since it gives you a chance to hold down the flimsy wood frame garage. From a practical standpoint reinforce and fill the cores where you have an anchor bolt.
A comparison with some good construction - They may have 32" or 48" reinforcement spacing for the lower one or two floors on a 20 story building. After that, it is less. Why go crazy on a garage?
Poor engineering is one of the reasons for the lack of masonry. Throw in an uneducated inspector in and you have a mess and less masonry.
Exactly, Concretemasonry. Combined with a total lack of knowledge of the difference between mortar and concrete, engineers tend to overbuild masonry structures, thus robbing them of their chief advantage: simplicity.
My point was that bad engineers and uneducated inspectors can lead to rediculous details and high costs, which decrease the amount of masonry used. I was not talking about liability since masonry codes have such an excessively high factor of safety and are proven to be much more reliable and adaptable to conditions than other building materials.
If California, they have some unique conditions and loads. I designed there. The engineers are quite good, but often have a high opinion of their abilities. Some feel the rest of the world should be built the same as the way they design for the worst conditions found in California. The fiasco with the blending of the UBC into the IBC is an example.
California does some great things in masonry in spite of trying to design for the world. I worked with local engineers when I was in Northridge after that quake and years later saw the great mason training they were doing at a high school near Fontana. - Cheerleaders at the masonry competition!!!
Some of the best masonry engineering I have seen was in South America. Often, the engineers work for the GC or developer and are a part of the job from beginning to end. This includes creating good, clear workable drawings and almost daily vists to the job (it may be 5 to 20 apartments 15 to 20 stories high).
These engineers are deeply involved and know their business. I asked one about what code they used and is answer was "WE USE YOUR CODE, BUT WE DO IT BETTER". Much of their knowledge goes back to the reinforced concretemasonry in San Diego in the late 1960's to 80's. They just took the modern engineering requirements, applied them to their conditions and made them workable and buildable. There would be more masonry in the U.S. if our engineers were more involved and knew more about masonry.
Dick
If California, they have some unique conditions and loads. I designed there. The engineers are quite good, but often have a high opinion of their abilities. Some feel the rest of the world should be built the same as the way they design for the worst conditions found in California. The fiasco with the blending of the UBC into the IBC is an example.
California does some great things in masonry in spite of trying to design for the world. I worked with local engineers when I was in Northridge after that quake and years later saw the great mason training they were doing at a high school near Fontana. - Cheerleaders at the masonry competition!!!
Some of the best masonry engineering I have seen was in South America. Often, the engineers work for the GC or developer and are a part of the job from beginning to end. This includes creating good, clear workable drawings and almost daily vists to the job (it may be 5 to 20 apartments 15 to 20 stories high).
These engineers are deeply involved and know their business. I asked one about what code they used and is answer was "WE USE YOUR CODE, BUT WE DO IT BETTER". Much of their knowledge goes back to the reinforced concretemasonry in San Diego in the late 1960's to 80's. They just took the modern engineering requirements, applied them to their conditions and made them workable and buildable. There would be more masonry in the U.S. if our engineers were more involved and knew more about masonry.
Dick
Let me give you an example of a job I was involved in that went to litigation. The engineer specified field testing of the mortar to a proportion specification, type S, and insisted that the mortar break at 1800PSI. To achieve this, the mason had to use such a stiff mix that the mortar cracked all over and leaked like a sieve.
Who was wrong? The mason did as specified, the engineer thought he was doing the right thing, per his normal concrete procedures and practices, and the owner got a crap building. Everyone involved lost money, just because the engineer did not understand mortar.
Who was wrong? The mason did as specified, the engineer thought he was doing the right thing, per his normal concrete procedures and practices, and the owner got a crap building. Everyone involved lost money, just because the engineer did not understand mortar.
The ASTM mortar spec (which I vote on) is one old inherited spec that engineers and architects do not read or understand.
You can specify what properties you want or you can specify what proportions you want used.
Both are good approaches, but a specifier cannot specify both.
To simplify - If you specify the performance (strength) you cannot control the proportions. If you specify the proportions, you have to accept the the strength you get.
Strength is not the criteria for mortar acceptabilty. Workability is the most important. The appendix to the specifications say that the specifier should specify the LOWEST mortar strength possible to carry the loads. Stronger is not always better. - You can make a 4500 psi block prism with 1900 psi mortar.
Dick
You can specify what properties you want or you can specify what proportions you want used.
Both are good approaches, but a specifier cannot specify both.
To simplify - If you specify the performance (strength) you cannot control the proportions. If you specify the proportions, you have to accept the the strength you get.
Strength is not the criteria for mortar acceptabilty. Workability is the most important. The appendix to the specifications say that the specifier should specify the LOWEST mortar strength possible to carry the loads. Stronger is not always better. - You can make a 4500 psi block prism with 1900 psi mortar.
Dick
Thanks to everyone that post an answer to my question. Here in Ohio, the price difference between 6's and 8's in about 10 cents. 96 for 6's and 108 for the 8's, so price is not a real big issue on such a small job. Concretemasonry you sure seem to know your stuff and really appreciate the information.
Masonry > 6 Inch Block Garage Foundation?????
Masonking02 -
Better yet, use 6" or 8" all the way and give the man a bigger garage.
Then there will be more work for masons everywhere.
12", 14" and 16" thick block walls are OK in their place, but they should not be used as an excuse for poor design or construction. - A waste of time and money.
Masonking02 -
Better yet, use 6" or 8" all the way and give the man a bigger garage.
Then there will be more work for masons everywhere.
12", 14" and 16" thick block walls are OK in their place, but they should not be used as an excuse for poor design or construction. - A waste of time and money.
In many places they make 12", 14" and 16" thick block for walls. There is a place for them if you have high lateral loads.
In places where they use a lot of 6" block for high rise buildings, they have no need for 12" block so they use 2-6" block on the first floor of a 20 story building. The need for 12" block is so low, the are only available on special order.
The 14" and 16" are for insecure engneers in the U.S. or for specal situations like a high garage wall in an apartment building or a foundaton wall under a 4" brick, 2" cavity and 8" back-up wall.
In places where they use a lot of 6" block for high rise buildings, they have no need for 12" block so they use 2-6" block on the first floor of a 20 story building. The need for 12" block is so low, the are only available on special order.
The 14" and 16" are for insecure engneers in the U.S. or for specal situations like a high garage wall in an apartment building or a foundaton wall under a 4" brick, 2" cavity and 8" back-up wall.
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