bricks vs boards

[Tryak]

We watched 5 students from our academy grade for their 1st and 2nd degree black belts today and I was wondering if anyone could compare the difficulty level of breaking 1 brick to an equivalent number of boards just so I have an idea. Thanks.

 

[Twin Fist]

bricks are hard to break since they do not "flex" the way a board will. This is due to the fact that the brick is a much denser substance than wood

 

[level7]

sort of a hijack but, why do they have to break boards? Other then making kindling and demonstrating power? Why? I never got into this or understood this.

 

[Xue Sheng]

Boards don't hit back

 

[exile]

(i) I had to break a brick for my shodan test. It's at least as difficult as breaking three one inch boards stacked on top of each other, without spacers, plus another half inch board for good measure. That's the biggest board break I've ever done, and the brick break was easily as tough.

(ii) A board in effect measures a unit of focused impact delivery. Boards don't hit back, just as barbells don't lift back—but that doesn't have anything to do with why you lift. You lift because increasing your weights in a bench press both measures your increase in strength over the last lifting session and contributes to the increase in strength you'll gain from the current session. Similarly, increasing the depth of your breaking stack measures the technical quality of your current force delivery, and contributes to the increase the correctness of your technique. A board is simply an objective measure of the combination of impact force with target accuracy. That's really all there is to it.

 

[Tryak]

level7,

Breaking was used a symbol to show the student breaking through obstacles in their own life as they obtain their next ranking. It is also used to show spectators the power the student has achieved in his or her techniques and to allow instructors to more easily assess (for faster techniques) that the student is properly generating power versus techniques which are thrown in the air.

 

[Twin Fist]

plus, when breaking, if your technique is bad,you WILL not complete the break,a nd will most likely get injured.

it's a great test/motivation

 

[StuartA]

I dont think you can effectively compare bricks and boards... what type of wood, what type of break etc.

I often read so and so broke 5 to 8 boards, which, from the boards I use seems impossible (the 8), but when I have seen a video of these boards, they are often much thiner than what we can get in the UK.

After a discussion about this with a friend of mine who lives in the US, he posted me what he called "US Boards".. one was much thiner and the other approx the same size as we use, but was much lighter! Not sure if it was the same wood, but the density seemed different, or it had been purposely dried out or something!

For breaks we use standard house bricks in the UK, but again a brick that maybe wetter inside is harder to break than a brick thats been oven dried.

On average however, in reply to the OP, Id say a brick is the equivilant to 2 decent quality, hard, pine boards. Though in the mind its equal to 3 as brick breaking is more of a mental challenge than wood.

Stuart

 

[dancingalone]

It really depends on the brick you are talking about. I use concrete slabs about an inch thick; it's equivalent to 3 boards without spacers. I've also seen some cheap terra cotta bricks purchased from Home Depot used in breaking demonstrations. Those are more like 2 wooden boards.

There are lots of tricks used for extra showmenship in public demos. You can bake bricks in a kiln at high temperature to weaken it and make it easier to smash.

 

[exile]

It really depends on the brick you are talking about. I use concrete slabs about an inch thick; it's equivalent to 3 boards without spacers.

That's exactly the kind I had to break in my BB test, except that it's closer to 1.75 inches for me. Grey, rough, mean–looking, eh? :uhohh:

I've also seen some cheap terra cotta bricks purchased from Home Depot used in breaking demonstrations. Those are more like 2 wooden boards.

I know that type—roofing tile kind of stuff. The extreme brittleness of terra cotta makes it a much easier break than concrete. A shock wave goes through terra cotta probably at close to what happens to glass under impact; with concrete, it's very different—concrete seems to damp down the shock wave, and you can feel the impact dying under your hammerfist or knifehand unless you absolutely nail that break. TF was alluding to this in connection with the lack of 'rebound' in concrete, I think. Technically, much more difficult than wood, for that very reason.

There are lots of tricks used for extra showmenship in public demos. You can bake bricks in a kiln at high temperature to weaken it and make it easier to smash.

Yes, and I have the feeling that the regulars on the breaking competitions at karate and TKD tournaments know all of them...

 

[IcemanSK]

I agree with those who talk about the variables, even in the same type of wood. We break 1" x 12" x 12" pine at my dojang. Sometimes, I get boards at the lumber yard & they break easily. Sometimes, they have so much sap in them that they don't break easily at all. The master from my sister school took one of my "impossible boards" back to his students that complain about boards that are either too easy or too hard.

I have 10 2" x 16" x 6" fence cap blocks of concrete in my back yard. They've been in the same place since March. It was 110 degrees for a few weeks this summer, but it rained last week. The difficulty in breaking them today would be a bit more than had I tried in July.

 

[Kacey]

We break the same kind of boards IcemanSK does - 1" x 12" x 12", purchased at the local lumber yard. There's a great deal of variation in boards - they can be wet (as in full of sap) or dry, the grain can be close and tight or loose and wide, grain can also be straight across in one direction or curled, there may or may not be knots in the wood, the wood could be freshly cut or it could have been sitting around for months, the weather could be humid or dry - all of these affect how easily a board breaks. Wetter wood is harder to break than drier wood, straighter grain breaks more easily than crooked grain, knots don't break at all, although I saw someone knock the knot out of the center of a piece of wood once - that was fun to watch; it took a lot of precision.

As has been said, wood will flex, while cement will not. When we break bricks, we usually break roofing tiles - not the terra cotta ones mentioned previously, but 1" x 12" by 18" tiles used on building roofs, purchased at materials yards. Tiles (bricks) will not flex at all - but they are more brittle than wood, and there is no grain to worry about (cement is a very homogeneous substance) so breaking tiles is purely based on power - hitting them hard enough to make them break. It is a different application than breaking wood.

 

[Tryak]

Wetter wood is harder to break than drier wood, straighter grain breaks more easily than crooked grain, knots don't break at all, although I saw someone knock the knot out of the center of a piece of wood once - that was fun to watch; it took a lot of precision.

That brings back memories. My very first board that I broke actually had a knot in it and everyone was fascinated how the board broke around the knot and then continued straight. http://img.photobucket.com/albums/v466/Mysterious437/SDC10174.jpg?t=1228088248

dancingalone, that sounds like the kind of bricks I saw being broken.

 

[Deaf Smith]

This depends on what the boards are made of.

Long time ago we found #3 white pine was the best, or I should say, easiest, board to break. Especially very dry ones. You could almost sneeze at them and they would break.

#1 white pine, especailly it it's wet or moist, is a much tougher. Almost no grain!

The bricks we use are 1 inch think haydike (I guess that's how you spell it.) You can get the at Lowe's.

So the thing is, it all depends on what your boards are made of.

Get a sample of both boards and bricks, and 5 lb bumb bell, and drop them from certian heights and see how much force is needed to break them. Then you will have a standard to judge by.

Deaf

 

[terryl965]

There is too many variables, like brick if you nake them for 12 hours you can just cough and the thing will break. Wood if you buy them from Century are treated and cooke dthey will break so easy my big toe could breal it by itself.

 

[Tryak]

This really wasnt an absolute technical discussions I just wanted a ballpark I do appreciate the responses though.

 

[exile]

This really wasnt an absolute technical discussions I just wanted a ballpark I do appreciate the responses though.

T., you need to bear in mind that when you ask a question on MartialTalk, you get serious answers!

 

[bluekey88]

As another side note...dimensioned lumber pruchased from the big box stores will be label in nominal dimensions. Actual dimensions of said lumber will be less. So a s4s 1x4 piece of wood (shaped 4 sides) will actually be 3/4"x3 1/2". They list it at the dimension the wood was before it was planed and sawed to finished dimensions.

So, typically, when we break 1" wood...we're actaully breakingt 3/4" wood.

Peace,
Erik

 

[BrandonLucas]

As another side note...dimensioned lumber pruchased from the big box stores will be label in nominal dimensions. Actual dimensions of said lumber will be less. So a s4s 1x4 piece of wood (shaped 4 sides) will actually be 3/4"x3 1/2". They list it at the dimension the wood was before it was planed and sawed to finished dimensions.

So, typically, when we break 1" wood...we're actaully breakingt 3/4" wood.

Peace,
Erik

I used to work in Home Depot in the lumber department....that's giving me unnecessary flashbacks.

 

[bluekey88]

I now gte all my lumber from an actaul lumber yard and dimension it myself....with the exception of my wood for breaking...Home depot cheap stuff all the way