Rough in for tilt up wall construction

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I am currently starting a project that consists of tilt up panel construction. I have never done a job like this and was hoping for some help. I need to rough in the walls for devices both inside and outside of the building. How do you guys do this. Do you run pvc in the walls and just support everything frlm the rebar?
If so what do you use to support boxes etc. Also if i am instaling boxes for receptacles on the inside of the building how do you support those boxes and assure that they will be flush with the inside of the wall. Do you just stub pvc up or down the wall?
I knlw this is a long post but I am just looking for some pointers. Any help would be appreciated. Pictures would also help.
Thanks a lot
 

Cow

Senior Member
Location
Eastern Oregon
Occupation
Electrician
I've never done anything but surface mount on tilt ups. Embedding boxes and conduit in the wall sounds like it'd be a challenge for the reasons you mentioned. I'll be interested to hear what the others have to say about it. I'd assume you tie wire/zip tie conduit to the rebar and stub a 90 out at either the top of bottom of the wall, but I can't think of a good way to keep the boxes flush or in the right position...
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
Each panel is a form. The one's facing in just need to be flush with the pour pad and then run a string across the form for the outside ones and make your box flush with the string. It's also important to know which end goes up. Usually the end by the slab edge is the down side.
 
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Ponchik

Senior Member
Location
CA
Occupation
Electronologist
To me the word "tilt up" means a pre made concrete wall that is brought to the site and erected.

How are you going to install conduit and boxes "INSIDE" that wall? As mentioned by COW your conduit work has to be surface mounted. Unless the wall has pre-built boxes in it with a conduit sticking up the top plate.
 
The panels are formed and poured on site and then lifted to form the building. I will have an opportunity to install boxes and conduit in the wall before it is poured.
 

480sparky

Senior Member
Location
Iowegia
I've taken two routes:

Sit down with the blueprints and create a layout for the casting company to follow, along with a generous supply of material.......... and they will set the boxes and raceways in the pour for me. I merely note which side of the wall the box is to go, what type/size of box, how far off the floor (AFF) it goes, and which side of the wall the stub-out is to go.

Or; I spend time at the factory that makes the walls and place the boxes & raceways myself.
 
The type of forms I have seen are usually a wood type material braced by metal brackets. The way I do it is with a long nail or screw thru the back of the mason box and out the front into the wooden form. It will hold the box firmly against the form. When the form is pulled off I just snap the screw off. As for the PVC, I just tie wire it to the rebar.
 

kingpb

Senior Member
Location
SE USA as far as you can go
Occupation
Engineer, Registered
Been a while, but from what I remember, we used concrete/masonry boxes; check Steel City products website.

Put a 3/4 in female PVC fitting in the box; the fitting is going to face downward. Then Using long pieces of tie-wire, doubled up, (no time to be cheap) run through the back holes in the box, (top and bottom) then use duct tape and tape the whole box to cover up any holes that concrete could possibly get in. (Again, no time to be cheap)

Then once the wall has been formed with steel, you go in with your boxes and place them at the elevations and direction you want.
We used to spray Thompson's water sealer on the front of duct tape of box, just to help concrete not stick to it.

Only one conduit per box, and the conduit should always go down towards the floor; that is, what will be the floor after the panel is lifted. You use tie wire to attach box and pvc pipe in wall to the framing steel rebar. A 90 deg stub should be poking out at the bottom of wall in the direction that will be in a free space after the wall goes up. Coordinate direction with wall guys and plans. Play nice with the steel/form guys cause they can really jack you up if you mess with their stuff.

On the edge of a tilt up perimeter, there is an apron that's a couple feet wide that will get filled in later after walls are up, this is where you hope all your 90's are showing up. Mark everything on your drawings to scale or you'll never find them later.

The best plans and coordination will result in most showing up. We used a little single jack to fine tune location of boxes after walls are up, since a thin film of concrete will be over front opening of box, but pretty easy to find them, for the most part. Just cut out duct tape after located.

Guaranteed you will not find them all, and will end up having to hammer drill some holes; plan accordingly.
 

iwire

Moderator
Staff member
Location
Massachusetts
Only one conduit per box, and the conduit should always go down towards the floor; that is, what will be the floor after the panel is lifted.

With one pipe to each box what are you doing to feed these boxes?

Individual home runs back to a panel?
 

kingpb

Senior Member
Location
SE USA as far as you can go
Occupation
Engineer, Registered
With one pipe to each box what are you doing to feed these boxes?

Individual home runs back to a panel?

Once the box stubs are available than you can go to j-boxes (surface mounted), panels, whatever you need to, using the open area next to the walls to route conduit. Once they finished the floor, it's all overhead and exposed.

Usually not a lot of stuff being imbedded; maybe for some wall packs, fire riser j-box, some recepts, signage; warehouse stuff.
 

Cheyenps

Member
Location
Yorba Linda, CA
That's pretty much how we do it too, but we run two stubs in the bottom of boxes that will be in the middle of circuit runs. We tilt the stub outs to about 45 degrees to make pulling in and out of those boxes easier. Wall packs get only one conduit stub and are routed to surface boxes fed via PVC in the pour strip after the walls are up.

The key to finding your boxes is meticulous record keeping - preferably on a copy of the concrete panel drawings. Better is to have someone there on pour day to look after the boxes.

Even then you'll likely lose a few.
 
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