Every building material has a theoretical limit which it can't be used beyond: at some point, the weight of material above is enough to crush what's below. Now, a team of engineers has worked out that limit for Legoâ€”and it's surprisingly high.

A team of researchers from the Open University in the UK decided to settle speculationâ€”including burning debates on Redditâ€”by tackling the question scientifically . As the BBC reports, here's how they did it.

### Under pressure

To work out how high a tower can be before it crushes itself, you need to know two things: the mass of material, and its yield strength. The yield strength describes how much loading a material can take before it begins to deform.

To work that out, you need a fancy device called a hydraulic testing machine. So, the engineers took their test specimenâ€”a 2x2 Lego brickâ€”and placed it into device. Then they ratcheted it up until things started getting interesting. They sailed past 770 pounds and wondered if they were doing something wrong. Eventually, the load reached 950 pounds and the brick began to slowly deformâ€”which is known as plastic failure.

It's not loud, it's not dramatic, but it was definitely the end of the lego brick, as you can see in the picture: it's squashed completely flat. Repeat experiments confirmed that the average 2x2 brick, each of which is made of ABS plastic in Lego's factories, can take 950 pounds.

### Do the math

Once you know how much load a brick can take, then working out how tall you can build a tower is fairly easy. A normal 2x2 Lego brick weighs just 1.152g. From that, you can work out how many you need to create the whopping 950 pounds that the brick at the bottom of a tower could take.