What's this mark on tape measure

[Mike Harrison]

Friend just bought a new tape measure - apart from all the usual inches,cm,feet etc. there is a diamond shape marked at intervals of just over 49cm (~19")

Anyone know what this might be for....?

[Jim]

inches,cm,feet etc. there is a

[Dave Baker]

inches,cm,feet etc. there is a

It's an American thing for spacing out joists and studs. The standard length of flooring or partitioning board there is 8ft (96 inches). The higher the load bearing capacity you need the more closely spaced the joists have to be. Dividing 96" into the commonly used integer spacings gives 8 x 12", 6 x

16", 5 x 19.2" and 4 x 24". The only one of those that isn't a nice round number is 19.2" so if you're spacing out at 5 joists per floor panel you can follow the diamond marks.

[Andy Dingley]

Cubits. Handy for ark building.

[mrcheerful]

Trim joist spacing:

It is customary to place traditional joists at 16-inches on-center. However, since the TrimJoist has a 3.5-inch wide flange, many contractors choose a 19.2-inch spacing to maximize the price/performance ratio of the product. Most contractor-grade tape measures now have a marker every 19.2 inches for just this very purpose. This spacing will also work out correctly for your plywood subfloor. By using a 19.2-inch spacing, the flanges of the TrimJoist are still only 15.7-inches apart. This makes the plywood subfloor behave like traditional joists at 16-inch centers.

mrcheerful

[Mary Fisher]

You don't need at tape measure for that! Unless everyone on the gang is armless of course ...

Mary

>

[raden]

In message , Andy Dingley writes

Or the occasional pyramid

[Mary Fisher]

Nice one!

[Dave Plowman (News)]

Sounds useful for equipment racks - 19" bays. ;-)

[raden]

In message , "Dave Plowman (News)" writes

That's the first thing I thought of, but then thought "Nah"

[Lurch]

On Fri, 21 Jan 2005 23:45:21 +0000 (GMT), "Dave Plowman (News)" strung together this:

I thought about that, but couldn't work out how or why ~19" would be of much use.

[Stefek Zaba]

Same set of mental processes here. Now seven-quarters-of-an-inch marks - yes, that's rack-layout heaven!

[Tony Williams]

If you buy enough 19" racking from Schroff the rep gives you a tape measure that is scaled in U's and HP's.

[Andy Dingley]

I have some '99 dot-com schwag that's just such a custom ruler. It looks like some bright spark at a hosting company went and had them run off by a vinyl sign printer, with their logo on.

Of course it appeals more to the box wrangler who might use it than the marketroid who places the hosting contract.

[bof]

Didn't Canford used to do a U ruler/tapemeasure? Or is my memory playing tricks again?

[Frank Erskine]

Indeed they do. It's marked in mm and rack units. The whole tape is

67U long.

Part no 55-921.

[Alistair Riddell]

I have a tape measure which is marked in mm on one side and rack-U (1.75") units on t'other.... Can be quite handy.

[Mary Fisher]

Spouse says it's for centring joists.

He assumes :-)

Mary

[Howard Neil]

Was that joists or jousts?

[Mary Fisher]

I suppose you ARE a long way from an optician ...

I googled, it IS joists.

Mary