Metric vs Imperial

[sbrown]

I need a quick lesson in Metric, tomorrow I will start a project in Metric with revit. I've never used the metric system so just some rules of thumb, ie a 3' door = what, stair rise over run 7/11 = what, 12" conc. wall = what. That kind of info. What is standard rounding?

Thanks in advance.

[Roger Evans]

Best to start in all millimetres ie rounded off 10ft= 3000mm = 3m

1"=25mm
2"=50mm
3"=75mm
4"= 100mm etc

1ft = 300mm
2ft = 600mm
3ft = 900mm etc

8x4 ply = 2.4x1.2 (still sold imperial)

OK?? Need More??

Mine's a 1/2 Litre thanks

Roger

PS Can you convert to & Use the metric template ?

[blads]

all you have to remember is that there is approx 300mm = 1 foot
(actuall conversion is 25.4mm = 1 inch)


ie a 3' door = what,

900mm approx


stair rise over run 7/11 = what

I assume thats 7" riser: 11" going which is 1 : 1.57


12" conc. wall = what

300mm approx.

hope this assists

[sbrown]

Thats perfect, thank you.

[Scott D Davis]

Kooky Hairy Dogs Bite Decent Citizen's Mothers

That's my Jr. High science teacher's saying for remembering the Metric Units:

Kilo Hecto Deka Base(units) Deci Centi Milli

Base is equal to 1 unit, everything to the right drops a decimal place, everything left gains a decimal place.

1000=100=10=1M=.1=.01=.001

I never forgot it, and now you wont either!

[beegee]

What is standard rounding?


Round (bankers) to the nearest millimeter.

Also, the default module ( at least in these parts ) is 300 mm. ( 300, 600, 900, 1200, 1500, 1800, 2100, 2400 etc )

Enjoy it !

[Dimitri Harvalias]

Scott,
A few suggestions from someone who had his early schooling in imperial, trained in metric, has worked using both and lives in a country that sells 4'x8' sheets of plywood in 13mm, 15mm and 19mm thicknesses!
- Don't fuss with decimal places. Use the mm as your standard unit for everything.
- In general there is no need to use hard conversions (eg calling up a 1" real world dimension as 25.4mm). I have never seen a framing contractor accurate enough to do rough carpentry down to 1/64th of an inch, although some of the recent threads regarding 'craftsmen' in MA might lead us to think otherwise.
- For gridlines, major partition locations, ceiling heights etc. try to keep the numbers ending in 0's and 5' (is someone really going to notice a 1/4" difference in their bedroom?)
- Once you have worked in metric you will never want to add up another dimension string in imperial (can you say fractions and common denominator?)
- Always take comfort in the fact that if you get lost in the metric world all you have to do is go to the Settings menu and flip back to imperial to get your bearings. Revit is great that way and I use this feature a great deal. Still dealing with clients who are comfortable with imperial units and a building code/municipal authority which only thinks metric.

Good luck and welcome to the 'rest of the world'

[Steve_Stafford]

Nice thread guys...thanks for the info!

[gregcashen]

Second that! Almost makes me want to go Metric...

[MartyC]

Metric Rocks!

In this part of the world everthing is metric in the graphic language but very often still Imperial in the spoken language, like, 'but how wide is that carpet at 3.6m', 'it's 12', just like it always was'. Down under a 2x4 is a 4x2, and 4'x8' sheet is 8'x4', sorta like driving on the correct side of the road. :shock:

Generally though timber, steel, masonry, if detailed properly, is actual size rounded to 1mm.

It really is eesy peesy! 8)

Cheers M

[beegee]

But a block of land is still 24 perches :!:

[rhys]

what about rods poles and chains :)
The important thing about going to metric is knowing the local metric conventions they vary. UK always uses mm not so in Germany where its cm,dm,m. So it depends where your metric building is. Local metric, window door standards also apply you can still get imperial or metric doors here metric are 626,726,826 x1981ht leaf sizes. giving Opening modules 700,800,900, Component Sizes i.e doorsets Actual 690,790,890 to fit structural openings 710,810,910. But if you were using imperial doors then a straight conversion would have to apply. My favourite is the standard metric brick 102.5x65xx215 yes 102.5mm!! We used to have metric modular bricks 200,300 x 75,100 whatever happended to them?

[PeterJ]

One other tip, Scott, is that anything that you have in Imperial which is comfortable and right is still going to be much the same in metric because the human scale remains the same, so our default ceramic tile is 150 x 150 mm to your 6 x 6" (though actually it may be 152 x 152 to suit grouting styles and so on). You should be able to think pretty much in the same materials and material relationships that you already do.

Codes will vary so if you are building somewhere other than your home state and that is what is forcing you metric then tht is likely to be the tougher issue for you. You will find assumptions about means of escape in case of fire vary widely around the world (maybe dependent on the value of life locally) and likewise general construction choices can differ. There is little or no tilt up concrete walling in the UK for example.

[rhys]

And we're seperated by a common language not much "stick" and "drywall" mitred or otherwise :) here, but quite a bit of "plasterboard and stud"

[Dimitri Harvalias]

One thing I forgot to mention Scott. Not sure about the rest of the world but in the Great White North metric convention is that there are no 'nominal' sizes. An imperial 2x4 is 1-1/2" x 3-1/2" a 3x10 is 2-1/2" x 9-1/4". In metric a 2x4 is an actual 38x89 (direct conversion of the actual dimension).
As Rhys metnioned you might wnat to check local conventions and availabilty of metric products. You may find yourself needing to lay out your t-bar ceiling at 1220x610 (a hard conversion of 2'x4') if metric fixtures (1200x600) aren't available in your area or the contractor/client needs to pay a premium for them.

[Paul P.]

I've only been donig this job for coming upto three years now so I am still learning all the time. (I work as an A.T.) My biggest gripe is that using the Metric system is fine, when people use. What I mean is not all buildings are designed to brick dims, and that standard off the peg windows are not to standard brick dim openings which means the need to cut bricks to make it work. This to me doesnt make sense.

[rhys]

I agree and I've been around for XXXXXyears. and I still don't understand the reason for the dimensioning of Uk windows off the peg. On very small jobs most brick layers can stretch the bond, or cut to make either standard metric or old standard imperial windows. For anything other than small jobs I always use purpose made brick dimmed windows.

[bclarch]

But a block of land is still 24 perches :!:

I'll bid 3 cod and 5 halibut for one block! :)

[Paul P.]

bclarch. Look at it, that's worth ten if it's worth a shekel.

[gregcashen]

uhh...Bob's yer uncle?

[David Sammons]

Scott,

I suggest you take a look at ASTM E-621 "Standard Practice for Use of Metric (SI) Units in Building Design and Construction" for additional information. This ASTM standard outlines a selection of SI units for general use in building design and construction.

Also, you may want to download the program named Convert from the following web link:

http://www.joshmadison.com/software/convert/

I use this program routinely for converting all sorts of units from imperial to metric and vice versa.

Dave S.