metric dimension units question

[Anonymous]

I work mainly using Imperial Units and have a few questions about Metric.
For those of you who do metric drawings, can you please answer the following questions:

Do you set dimension prefs to meter, centimeter, or milllimeter?

Do you use different settings for different kinds of drawings, i.e., floorplans in millimeter and details in centimeter,etc.

How do you indicate roof slopes? (In the US we use "x" number of feet in 12 feet)

thanks,
Dan K

[Jere]

roof slopes are simplest ratios. For example, a 4/12 pitch would be expressed as 1/3. A 6/12 would be 1/2 and a 7/12 would be, well, 7/12.

In Canada, and i'm assuming the USA as well, there are standards that dictate what units to use. Generally it'll be millimeters for everything except meters can be used for site plans.

Canada is in the same boat as the US in the sense that we're officially metric, but most people think in imperial, especially tradesmen.

I also think the unit standards are ridiculous. It seems ludicrous to dimension a building as 12 350mm long. 12.4 m would be better. Also, i think detailing would be much better in cm rather than millimeters. two decimal places would be appropriate for plans with one being appropriate for detail. But, like i said, that's not the standard.

I believe cm's are the standard in europe.

[Anonymous]

Plans are usually dimensioned in cm. Steel structures have to be in mm. For details it depends on the scale and the detail itself.

Roof slopes are shown in decimal degrees, fractions (1:3) or percentage (1:3=33%). Builders prefer them in percentage, so I usually show slope in persentage too.

[KeesW]

In Australia we dimension plans in millimeters, although we can use meters. We don't need to label the dimensions as 'mm' or 'm' because it is usually obvious (because they differ by 1000x). We don't normally use fractions for mm. I understand that where countries use 'cm', they actually use decimals, eg 12.3cm, and they label their dimensions because it is not so obvious what is being used.