2 x 2 versus 600 x 600

[charlie b]

An architect is concerned that the 2 foot by 2 foot (603 mm x 603mm) light fixtures that I showed on my plans are not going to fit with the 600 mm x 600 mm ceiling grid that he is showing on his plans. This is a suspended ceiling and the fixtures are recessed troffers. I don't know how these things are actually built, so I don't know if that extra 1.5 mm on each edge is going to be a real problem. Can anyone shed some light (sorry about that) on this issue for me?

 

[roger]

An architect is concerned that the 2 foot by 2 foot (603 mm x 603mm) light fixtures that I showed on my plans are not going to fit with the 600 mm x 600 mm ceiling grid that he is showing on his plans. This is a suspended ceiling and the fixtures are recessed troffers. I don't know how these things are actually built, so I don't know if that extra 1.5 mm on each edge is going to be a real problem. Can anyone shed some light (sorry about that) on this issue for me?

Charlie, we bid a Federal Building a few years ago and had to get prices on metric lay-ins, they are definitely different animals and I believe it carried over to the lamps.

BTW, I liked the pun.

Roger

 

[steve66]

It shouldn't be a problem. 2x2 recessed lights are made to fit in a 2x2 ceiling grid. The openings in the grid are less than 2'x2' - they are just spaced 2' on center (i.e. 2' from center of tbar to center of tbar).

Edit: I didn't see Rogers post before I posted. I'm assuming Charlie is using an English 2'x2' grid since 600 mm is almost exactly 2'.

 

[Smart $]

... I'm assuming Charlie is using an English 2'x2' grid since 600 mm is almost exactly 2'.

Almost don't get it in this regard. A 2' x 2' grid is closer to 610mm x 610mm.

 

[GoldDigger]

Almost don't get it in this regard. A 2' x 2' grid is closer to 610mm x 610mm.

And that is definitely not going to fit into a metric 600x600 grid unless the clearances are incredibly generous to start with.

 

[Smart $]

And that is definitely not going to fit into a metric 600x600 grid unless the clearances are incredibly generous to start with.

I quite certain you can scratch that last part off. :happyyes:

 

[JFletcher]

.

https://books.google.com/books?id=p...ge&q=metric vs standard ceiling tiles&f=false

I figured it was a difference in terminology being that 2x2 and 600x600 are only .8cm off dimensionally, and it would make zero sense to market two products virtually identical but pretty much incompatible, at least in ceiling grids.

 

[Fulthrotl]

An architect is concerned that the 2 foot by 2 foot (603 mm x 603mm) light fixtures that I showed on my plans are not going to fit with the 600 mm x 600 mm ceiling grid that he is showing on his plans. This is a suspended ceiling and the fixtures are recessed troffers. I don't know how these things are actually built, so I don't know if that extra 1.5 mm on each edge is going to be a real problem. Can anyone shed some light (sorry about that) on this issue for me?

m'kay.... who uses metric ceiling in the US?

1MM=.03945" so you are going to gain an eighth inch or so... if you
put two fixtures end to end, i suspect a problem with fit. putting fixtures
into the correct size grid is sometimes like packing a marshmallow into a
piggy bank.....

 

[charlie b]

The spec sheet puts the fixture at 603 x 603.

 

[roger]

m'kay.... who uses metric ceiling in the US?

The GSA

Roger

 

[jusme123]

The spec sheet puts the fixture at 603 x 603.

then the prints for ceiling layout should reflect the size fixture being installed.

 

[roger]

For anybody interested see page 31 of this document

Roger

 

[jumper]

For anybody interested see page 31 of this document

Roger

Nice link.:thumbsup:

 

[iwire]

The GSA

My only experience with the GSA has lead me to believe they are a worthless taxpayer expense.

It was like they picked a random unemployable guy, handed him a multi-meter and told him to supervise the electrical installation I was doing for code and specification compliance. I don't know what he was knowledgable in but I know it was not electrical work.

 

[roger]

My only experience with the GSA has lead me to believe they are a worthless taxpayer expense.

Well, I'm not going to argue that point.

Roger

 

[jumper]

It was like they picked a random unemployable guy, handed him a multi-meter and told him to supervise the electrical installation I was doing for code and specification compliance. I don't know what he was knowledgable in but I know it was not electrical work.

DoD projects ain't much different.

 

[GoldDigger]

For anybody interested see page 31 of this document

Roger

Relevant portion, starting on page 30 as I see it,:

When a round metric 600 by 600 or 600 by 1 200 ceiling grid is installed, round metric lay-in type fixture sizes must match.
Many fixture manufacturers currently produce or can produce both modular metric sizes and still utilize currently used standard bulb sizes.

 

[roger]

Relevant portion, starting on page 30 as I see it,:

I need to clarify that my reference to page 31 was the PDF page, which is page 25 of the actual document.

Roger

 

[Smart $]

I need to clarify that my reference to page 31 was the PDF page, which is page 25 of the actual document.

Roger

Near bottom of document page 30 (pdf page 36) is what GD quoted... and perhaps just as pertinent as it goes on to list known US manufacturers.

PS: I wish document regarding metric sizing would at least get the counterpart name(s) right. English is a dated term that has been replaced by Imperial (aka British Imperial) for about 200 years now. US units of measure can simply be referred to as US customary units.

 

[steve66]

So it really is a metric ceiling grid. That's crazy - that the GSA would spec that in the US?

I'm surprised its so close to our standard English (Imperial for Smart$) grid. I guess its probably because they use the same 2' and 4' nominal length lamps in other countries? Or do they use different lamps in other countries?