rebar in block to hearth

[mrpbjnance]

I am going to fill the core of my blocks tomorrow.

does anyone have any good tips?

Can the rebar stick up so that it will tie into my hearth or should I cut it off?


thanks
Mike

[dmun]

It's great if your rebar sticks up into the slab to tie it to the base: Just don't let it get near the surface. Rusty rebar can grow and cause cracks.

For the block holes you aren't filling: Just jam crumpled cement bags into the holes to block them up.

Good luck, thats LOTS of work.

[mrpbjnance]

Thanks DMUM

I am going to use concrete backer board and leave it there.. so that will cover thoe holes.. only kicker there is i will need to cut holes in thebacker board for the rebar.

I had help for the slab and have stacked the blocks .. I was hoping filling the cores would be easy... I think mixing the cement for the hearth willbe the most trouble but I do have a mixer.

Hope my back holds out.

Thx again

Mike

[christo]

filling cores

Glad you have a mixer. Make sure you have plenty of concrete materials.

Filling the cores, even every other one, took more concrete than I thought. I think I remember it was ~.25 cu ft to fill both cores of a standard block.

Finally a small break from the +90 degree weather we've been having. I'm going to play with my oven project today!!!

[KISS4me]

Filling cores over opening

The suggestion to use crumpled up cement bags to prevent the hearth pour from going down the empty holes is a good one. I was wondering how I was going to overcome this problem. My question is in regards to the layer of blocks over the stand opening resting on angle iron.

Should each of these holes be filled? What is the simplest way to stop the concrete from coming out the bottom between the angle iron?

Steve (still planning, sourcing materials, and finding the time to get started)

[maver]

over opening blocks

I did not fill these. I think the purpose of filling the cores in the stand is to create a rigid column. Since the blocks over the opening are single layer there is no added rigidity by filling them - just extra work. If you wanted to fill the voids (did you spend extra time coloring all your drawings in kindergarten ) then you could support a wood form under the opening during the pour. You would be depriving spiders of a nice home.

[CanuckJim]

Mortar coming out

No doubt, you'll have lots of brick and block pieces lying about. Drop a couple down the cores of the angle iron block where the gaps are. Sure, you'll get some water leakage, but not a lot. Works.

Jim

[redbricknick]

core.

When we poured our hearth slab, we came up with what we thought was a pretty cool innovation. We put rebar in all of the cores, and left it five and a half feet above the top of the cores before filling them. After it was cured, and our form was built, we bent the rebar over to create the rebar mesh for our hearth slab.

[dmun]

I found I couldn't bend re-bar at all. It was too tough to bend, and if i scored it at the bend point it broke off. Any hints on re-bar bending?

[redbricknick]

get bent

I found I couldn't bend re-bar at all. It was too tough to bend, and if i scored it at the bend point it broke off. Any hints on re-bar bending?

To bend our rebar, we first had it anchored, then slotted an eight foot metal pipe over it to bend it. A vice would suffice if the rebar wasn't anchored into cores like ours was.

[maver]

rebar bender

I used the grab handle in a man hole cover - we have some rectangular utility access panels in our street that have a handle that slides up enough to slide rebar under, the cover is bolted down so it does not move at all. Check your neighborhood. No good if it's already in your block stand though. There is a tool for this also - I've seen it at the rental places.

[CanuckJim]

Bent Already

Dmun and all,

I've used all kinds of methods to bend rebar, but I agree that a piece of pipe works really well. On job sites, we've used the bumper of an old Ford pickup. For sharp bends, try a bench vise, pipe and, last, a two pound hammer to get the final shape.

Jim

[james]

There is a tool you can use. It isn't complicated and is the most accurate. I don't know if the rental companies have those.

I bent and tied three courses of rebar for the perimeter foundation on our last house extension project -- never again! I couldn't use my hands for a week. That's a job for the foundation contractor next time.

But the rebar bending tool set the angle right where you needed it to stay in the center of the foundation form.

James

[KISS4me]

Filling opening blocks

Thanks for advice on filling these cores over the opening. Just confirming that you recommend throwing some rubble down these, then stuff some paper to impede hearth pour block rather than filling them with concrete. Agree?

The bending of reo rods .............. why not bend before placing in cores?
Steve

[dmun]

The bending of reo rods .............. why not bend before placing in cores?
Steve

Because they are brutally hard to bend. If you put them in a vise, they slip out. Standing on them and lifting doesn't work. Scoring them with the angle grinder makes them break. There is no doubt a tool for doing this, but the main problem is holding them. Burying one end in the concrete solves the workholding problem.