# Forum Home Renovation Brickwork  Bond Beam??

## dub3media

What is it, Inspector wants to see it before the grouting of the concrete blocks! 
I have a block foundation wall 2 blocks high going around the perimter of the building, and will have a 100mm concrete slab poured up to the top of the header block! 
Does it lie in the header block and poured in with the grout of the blocks, or is it poured when the slab is poured.??? 
thanks, have an inspection on tuesday so stressing a little!

----------


## myla

hello, 
bond beam is a combination of steel and concrete placed in your block work 
vertical bars and horizontal bars laid in the bed typically,  
you should have a specification in engineering documents  
thanks
myla

----------


## Blocklayer

Can you post a pic of what you have so far? 
:

----------


## journeyman Mick

Depends on how the builder/concreter/whomever is doing it. I'm guessing that they'll lay the steel in the blocks and pour the fill in the blocks at the same time as they are pouring the slab. In this case inspection would be just prior to the placement of the concrete. Basically the inspector will want to see that all the steel is in place and of the correct size before it's covered. 
Mick

----------


## autogenous

> you should have a specification in engineering documents

  No engineers detail? 
A picture?

----------


## dub3media

sorry couldnt get into forum, server said it was busy??? 
I have a pic but not on this computer. 
Basically I have a strip footing which is 400 wide by 500 deep, with d12 starters @600 crs coming up through the footing, these same starters will go through my block work ( 190 x390 blocks 2 courses high only) the same starters will then bend over into my concrete slab which will get poured after the blocks have been grouted. 
My question is the inspector is coming on tuesday for a grouting inspection, to see if blocks have vertical starters in them. 
I laid the blocks a couple of days ago the bottom course block is the standard block and the top block is a half bond knockout block. 
The inspector last time mentioned a "bond Beam" as in the d12 running horizontally at the top of the block, does the bond beam steel get poured in with the block grout or does it sit in after the grout has been poured and then get poured in with the 100mm concrete slab??? 
Will see if i can find a similar pic on the net to explain!.  
Thanks for all your replys

----------


## dub3media

I found a pic, the only thing different about my situation is I am only 2 blocks high, and I have vertical starters @600crs to tie into the floor slab. 
Makes it a little clearer when looking at the pic, so the blocks are grouted then the horizontal d12 (is this the "bond beam") is placed on top ready for the final slab pour.??

----------


## myla

hello, 
the horizontal D12 should be tied to the starter bars, the horizontal is for the blockwall to strengthen/reinforce to take "whatever" is going to be done 
the vertical starter bars are for "connection" to main floor/slab 
surely the blockwork would be filled prior to main floor/slab construction  
thanks
myla

----------


## journeyman Mick

I'd be pouring the lot in one go, unless the specs for the corefill is vastly different to the slab. Even then, you could core fill the blocks from one truck and schedule the rest of the concrete to come straight after and just keep placing. Best bet is to discuss it with your builder or concretor.  
Mick

----------


## dub3media

Hi Mick, yeah I was wanting to pour the whole lot in one go, but dont the blocks have to be filled so they have some strength when pouring the main floor slab, will the mortar hold the blocks when pouring up to them?

----------


## dub3media

both specs for core and slab are 25mpa, seaspray zone!

----------


## journeyman Mick

I'm assuming the slab is just 100 - 150mm thick with maybe some edge thickening (or possibly not, the bondbeam may be taking care of that), if so, the blocks should be fine to act as formwork.  
Mick

----------


## dub3media

yeah just 100mm slab no thickening, just 100mm concrete, 50mm polystyrene, just thought the blocks might move if I tried to pour all in one go!, you think the inspector would pass it to do one pour! have you done this before Mick?

----------


## myla

hello, 
we normally do prior to next stage works, 
for estimation purposes on concrete for core-filling, i think it is 1 cubic-metre to 50 blocks (19.01 series, 190mm blocs) 
thanks
myla

----------


## journeyman Mick

> yeah just 100mm slab no thickening, just 100mm concrete, 50mm polystyrene, just thought the blocks might move if I tried to pour all in one go!, you think the inspector would pass it to do one pour!* have you done this before Mick?*

  Not personally  :Rolleyes:  I hate working with concrete. Ran a few jobs that were similar, but generally the concreter was contracted to take care of it all. 
Mick

----------


## Blocklayer

We use a knockout on the top course, with the inside broken off, so the concrete flows right to the edge (almost) and down the block cores. So the top of the 2 course base is the top of the slab. The top outside edge of the block is visible on top of the slab, but if theres a wall on top/tiles etc it covers it. 
Here, for 2 or 3 courses we poor the slab and core fill in 1 go. For higher bases you may break/move the wall when filling/compacting the base. 
I haven't seen anyone use horizontal reo around the knockout, but it would be easy to do. The mesh goes almost to the edge and right angle bent reo can go out of the block cores into the slab and tied to the mesh. We break the inside off the top knockout course after the blocks are laid, but it can be tricky. You must give the mortar time to dry and use a decent mix, or you'll loosen/break the whole thing. Depending on the blocks, it can be easier to break them before they're laid

----------

