Vertical rebar in footings

[Sparticle]

It's odd that there is no home building sub forum. Anyway...

Has anyone used 1/2" PVC sleeves set into the footers to later accept the full length vertical rebar; (used along with shorter L shaped rebar anchors to tie the footer to the wall)? Seems like it'd be easier than inserting shorter vertical length rebar and then having to hand tie the extensions to extend up the wall. I know you aren't supposed to jab the long lengths into the ground.

I saw the idea in "living homes" and my husband and I were wondering if anyone has done this.

[Curtis B]

The point of leaving the rebar sticking up is to bond to the footer to the wall. If you had the PVC pipe in the footer you wouldn't have a good bond. If you wanted to avoid the rebar sticking up you could drill, and epxoy the rebar in, but the epoxy is VERRRRRRY expensive.

[Windy in Kansas]

If you do it right buildings don't get tired and lay down.
http://foxyurl.com/OL1

That Chinese building had an underground parking garage being built and as dirt was removed from one side of the building it was placed on the opposite side. The soil pressure along with wet conditions simply caused the building to shift sideways and as it did it snapped the pilings as they contained no rebar. I can't get the other photos easily but it shows close ups of the snapped pilings. They were also of hollow design.

At least the building showed strength in that it remained fairly well intact during impact.

[Bearfootfarm]

I know you aren't supposed to jab the long lengths into the ground.

I've always seen them driven in with a sledge hammer ( the shorter pieces)
I've also seen them used to support horizontal pieces in the footing

I think if you used pipe you'd run into problems of them being out of line or blocked with concrete

[Sparticle]

Thanks Curtis and Bear. Exactly the kind of feedback I needed. Gotta love this place!

[rambler]

I think you wouldn't have any rebar holding anything, just the plastic pipe doing the 're-enforcing'?

The point of the rebar is to be embedded in the concrete, tying everything together. You don't want it in a loose sleeve.

--->Paul

[o&itw]

When I poured my footings, I had a stake driven at each corner up by the batter bars. It was set with a nail in the top where I wanted the rebar. After pouring the footing and leveling it, I pulled a string and simply stuck the rebar down in the footing. A couple of jiggles and the concrete settled right in around it. We had to carry some of the inside forms to a place where the bars didn't stick up to get them through, but the good tie in was well worth it to us. When the footings dried, we bent the ones that weren't perfectly plumb to 90 degrees, set our outside forms first, then tied the horizontal rebar to the verticals, and some of the form pins.

Don't know if it was the "right" way, but it worked well for us.

[GoldenCityMuse]

Actually, What I think, is that they use the PVC sleeve to contain the full length rebar as you pound it in the ground. It keeps the rebar from bending, as it is not very rigid at 8' long.

After the rebar is a foot or so into the ground, you then pull up the PVC pipe and go to the next spot and do again.

Make sense?

[CamM]

The way I understand it, the L shaped rebar is set in before the concrete is poured, probably to the two rebars running horizontally along the footing. A keyway is another way to tie a footing to a wall. Just place a 2x4 in the center along the length of the footing, and when the concrete is cured pull the wood out. Wood may be cheaper than setting L shapes 6' apart. Vertical rebar in a wall may not even be necessary, since its purpose is to help with tensile strength. I think sometimes two bars running parallel to the footing are added in a wall, and yes, other times vertical dowels.

[Toads tool]

Originally Posted by GoldenCityMuse

Actually, What I think, is that they use the PVC sleeve to contain the full length rebar as you pound it in the ground. It keeps the rebar from bending, as it is not very rigid at 8' long.

After the rebar is a foot or so into the ground, you then pull up the PVC pipe and go to the next spot and do again.

Make sense?

Ding Ding Ding we got a winner.

[Windy in Kansas]

Worked some construction as a second job for a few months in 1968. We wired rebar into place and to each other, then welded it all together thus eliminating the weakness of the wired joint. Should the concrete fail the wire could have given way but with a welded joint very unlikely, and yes it would be unlikely the concrete would give way enough for a wire joint to fail.

[65284]

If you use 2"x4" keyway you better chamfer the 2" edges and lay the 4" side with the chamfer down. Unless of course you enjoy digging, hacking, prying and pulling to get it out of the footing.

Welding severely weakens rebar and would not be allowed on any job I ever worked. That includes large sports arenas, hospitals, power plants, big college dorms, etc,

[Windy in Kansas]

Originally Posted by 65284

Welding severely weakens rebar and would not be allowed on any job I ever worked. That includes large sports arenas, hospitals, power plants, big college dorms, etc,

The bosses probably didn't even know that back in 1969.

[Sparticle]

Originally Posted by GoldenCityMuse

Actually, What I think, is that they use the PVC sleeve to contain the full length rebar as you pound it in the ground. It keeps the rebar from bending, as it is not very rigid at 8' long.

After the rebar is a foot or so into the ground, you then pull up the PVC pipe and go to the next spot and do again.

Make sense?

Nope the PVC was left in, well that's what the book says. But you guys have me convinced not to do that.

[Sparticle]

Originally Posted by 65284

If you use 2"x4" keyway you better chamfer the 2" edges and lay the 4" side with the chamfer down. Unless of course you enjoy digging, hacking, prying and pulling to get it out of the footing.

Welding severely weakens rebar and would not be allowed on any job I ever worked. That includes large sports arenas, hospitals, power plants, big college dorms, etc,

We read about keyway and I can't remember why but husband doesn't want to do it that way. good to know that about welding. I've learned so much about construction these last 2 years!

[lilray]

You could bend the rod so that the part you want to tie in later is on then surface let it get good and hard. Then bend it straight. I put a piece of pipe about 6 ft. on it than bend.

[stanb999]

Originally Posted by Sparticle

We read about keyway and I can't remember why but husband doesn't want to do it that way. good to know that about welding. I've learned so much about construction these last 2 years!

I would definitely reconsider using the key way. In doesn't have to be large but it will "help" waterproof the wall.

What you do is take a 2X4 and cut 1" of the corners off leaving it beveled. Then you put tank sealing rope in the key way before you cast the wall.(they use it for sealing tanks or for manholes to seal between the joints.) This will make a waterproof joint. The weight of the wet concrete compresses the seal it works well and is inexpensive.

[Jalopy]

When we poured our 9 foot basement walls we did both, short L shaped rebar in the footings and also used the 2 X 4 for the keyway. We did not bevel the 2 x4 as we took it out after 3-4 hours after the cement set but before everything was totally dry. Since I am frugal/ cheap that way we could reuse the 2 X4 for other parts of the construction project.

[Farmerwilly2]

I guess I still don't get the pvc thing. Rebar is meant to be surrounded by the concrete. The steel isn't meant to be driven into the ground or surounded by plastic. You try to avoid letting water have contact with the steel to keep it from corroding. It's critical enough that in the most important jobs (think nuke plant) they'll use teflon coated rebar to keep the bar from corroding. Expensive as all get out, but makes some of the best mater stakes around.