I haven't run conduit in concrete before and I was wondering if anyone out there knew of any good sites to get info? Looking to run it in the slab and walls in new construction. Any resources would be appreciated. Thanks Guys!
In my experience, cement workers are nowhere near as brutal to the UG work as landscapers Smurf can be a pain to fish due to its tendency to run in almost any direction but "straight". For short runs smurf tube is ok, but use sched 40 pvc for the long stuff and try to make gentle bends and turns in straight lengths of pipe rather than 90 and 45 things to death. In an ideal world, you could have just two 90's.. at each end of the run. You will notice a big difference at pull time. This counts double for long runs, where a fish tape tends to want to bunch up in the straight mid section of the run rather than navigate bend after bend. If you are doing a really really long run and anticipate needing some strong pulling force, you might want to use metal 90's, as these are not suceptable to "burn through" from the heat caused by the friction of pullstrings or wires. I have seen this only in extremely long pulls (~100 feet and over), but it is something to consider... Hope that helps.
Re: Running Conduit in Slab#48063 02/02/0510:45 PM02/02/0510:45 PM
I am kind of "anal" about my work, and I will share one more thing, optional for all but the kooky neatnicks like me- you can use rebar "stakes" driven into the ground and tie wire to keep your conduits straight and level where they come up out of the slab. I have also seen 1/2" emt used to do the same.. In this case I have observed that concrete workers don't care (and really why should they?) where YOUR pipes come up.. if they come up inside the wall or, 3" outside it. It's just one way to ensure that your pipes stay where the plan intends them to be. I have never had a concrete guy not respect my intentions as far as UG pipe goes when I went to the trouble of bracing it so it stands up the right way and in the place it was intended to go.
Re: Running Conduit in Slab#48064 02/03/0506:07 AM02/03/0506:07 AM
Run schedule 40 pvc , use rigid 90 to turn up out of the pour, (I even go as far as putting 6" rigid nipples on the 90 to make sure they end up above the pour) I tried using pvc 90 but they break when some one trips on them or hits them , stake the pipe down - it will float if not plus concrete men will trip on it kick it etc etc use as few factory 90 in the pour as possible - just " bow " the pipe it will pull easier later on, tie the pipe down, make sure all stub ups are straight by staking the 90 with long peices of 1/2 emt the emt can be cut off /broken off later, oh yeah make sure you tie down the pipe. securing the conduit is importent -one thing I always do is to put my big yellow boots on and be right there when the concrete is poured. Have a box with fittings, glue , tie wire , tools etc etc with you , this way you will be ready if a pipe gets broken. But do not be afraid to " keep " the concrete men in line ! I have run thousands of feet of pvc in the slab. One more very important item - MAKE SURE NO STONES/ DEBRIS GET INTO THE PIPE.
Re: Running Conduit in Slab#48066 02/03/0507:25 PM02/03/0507:25 PM
Robbie you should always use PVC for underground work. The acid in the soil will not eat away at it as it would the metal conduits. I also use rebar to support my ppie coming up out of the slab. And I will ALWAYS let at least 2 1/2 - 3 foot of pipe stick above the slab. This will lessen your chances of getting cement into you pipe and the other contractors will see it and not have it as a tripping hazard. When the time comes to trim your pipe just cut the pipe and the rebar flush. I also use a vacuum to suck my pull string through rather then fight pushing a fish tape around the corners.
Good luck, hope these few tips will work for you.
Re: Running Conduit in Slab#48069 02/04/0502:38 PM02/04/0502:38 PM
I always used a full 10 foot stick of rigid metal conduit where I came out of the slab. Reason one: at least five feet of metal gives a lot of strength to the sweep. Reason 2: 3-5 feet of riser is noticed, and gives me a chance to straighten the pipe easily if it needs tweaking when it comes time to finish the run. As far as bonding the conduit, I would depend on the locknuts in the box for the bond.