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Discussion Starter #1
what is the best way to run a raceway through floor trusess in residential construction? I have heard of guys using scrap pieces of osb and drilling a few 2 in. holes in them and nailing that to every floor truss and run all your romex in that, do you have to derate anything even though it is a open raceway and you will have all your conductors running through there or is there a better way to do this, any help would be great thanks
 

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Is this in a basement or crawl space? Is it exposed? If yes to these two questions see below.

For NM cables larger than #8 you can staple the cable directly to the bottom of the joist. No holes or running boards required. For NM cables smaller than #8, you must use bored holes or running boards.
If you have access to a code book or can find one online, check article 334.15(C).
Hope that makes sense?
 

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" Euro " electrician
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The other thing let me add to this with the floor trusses you have to becarefull with drilling the holes some are pretty picky where to drill it escpally if you have microlamited beams that part can screw up the plans if not done right.

Wooden I beams floor trusses are useally not too bad but check with the manufacter details for more info or ask them for RFI { request for infomation } details and they useally more than happy to give you the info.

However., with microlamited beams this is very circital you have to check with them very carefully I useally try to advoid drilling them much as I can unless I get RFI to verify it first.

Merci,Marc
 

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The other thing let me add to this with the floor trusses you have to becarefull with drilling the holes some are pretty picky where to drill it escpally if you have microlamited beams that part can screw up the plans if not done right.

Wooden I beams floor trusses are useally not too bad but check with the manufacter details for more info or ask them for RFI { request for infomation } details and they useally more than happy to give you the info.

However., with microlamited beams this is very circital you have to check with them very carefully I useally try to advoid drilling them much as I can unless I get RFI to verify it first.

Merci,Marc
Marc, Very good point. With these newer type I beams I would say running boards would be the only way to go. But I people are drilling them. Even the NEC 2008 does not take these new I beams into account or mention them. Definitely something to keep in mind.:thumbsup: Thanks.
 

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Sure no problem at all J.V.

That why I want to head up with the readers here to forewarn about it before they mess around with the floor joints that something they have to think about ahead of the time.

Unforetally the NEC never say the words in there mention about new I beams or microlams at all so it more like in IBC { international building code } that part it will show up for sure.

I know the electricians are famuair with the electrical codes but not 100% with IBC so it will be wise idea from time to time check it out sometime it will really save yourself alot of greif or headaches if something can really screw up the plan.

Merci,Marc
 

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Discussion Starter #6
thanks guys, these are actual trusses not I beam or joist so they have open webs in them already and I am running 12 and 14 gauge wire through them I am looking for a way to group them togeather to be nice and neat and also pass inspection.
 

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sorry I forgot to tell you this is in a basement and I think when j.v. says running boards we are must be talking about the same thing.
 

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thanks guys, these are actual trusses not I beam or joist so they have open webs in them already and I am running 12 and 14 gauge wire through them I am looking for a way to group them togeather to be nice and neat and also pass inspection.
Are these trusses/joists wood or metal? You say "open webs". What exactly do you mean by this? Most all residential floor joists are wood planks like 2x10's or 2x12's. Or pre-fabed joists like mentioned above? Joists hold up houses (floors). Trusses hold up roofs. So you have joists, not trusses in the basement. I'm no carpenter, but thats how we refer to them. Just to clarify.
Please explain or take a quick picture.

Running boards are just lengths of wood nailed or screwed to trusses or joists so you can then run your cables on them with staples. So you do not have to drill any holes. :thumbsup:
 

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Ahh now we are getting somewhere .,

Open web floor trusses here the pic what it look like





that useally have no issue with staple the cable up at all just do like what the normal twoby's but one golden rules with floor trusses is do not cut any frame members at all it is allready under compression and tension espceally with upper and lower chords.

I did see alot of home use the floor trusses especally with pretty long span and they do hold up a bit of weight.

Now to run the wires in floor trusses in open web format that is not a issue due they designed to accumated HVAC or plumming in there without much issue and yes you can nail them on the vertical chords.

Merci,Marc
 

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He did use the word trusses in his first post....:) Not to be confused with joist or I-beam...:jester: I missed that too...:thumbsup:
 
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