# Forum Home Renovation Retaining Walls  limestone block mortar gaps

## straydog

I'm planning to build a retaining wall with 350x350x1000 reconstituted limestone blocks.  Can anyone experienced with using large blocks like these advise on how you get the mortar gap to be the perfect height?  I've done a fair bit of brick laying but with bricks you just tap the brick down with the trowel until its at the correct height.  Theres no way you can tap these 240kg blocks into place!  Someone said they use spacers of some sort but I can't find any info about this.

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## myla

hi, 
what size you be after? 10mm 
basically, dry mix and right amount on each bed, you will get some movement ie. taping them down 
it will be trial and error, see how much it sucks h2o out of the mortar 
make sure you have good lifting device
thanks

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## jago

I've done a couple of heavy block walls that required a even grout line and we used slivers of solid brick cuts (used a diamond saw) pushed in to motar beds to get the correct heights. Ensure your blocks are wet down and your mix is not too wet. If you are going to tamp use a rubber mallet same as laying pavers 
How are you planning to lift these in to place? :2thumbsup:

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## straydog

I'm planning to build a steel gantry to hold a chain block and use that to lift them into place.  I can't get access with a bobcat or dingo type machine.  We have just bought the house and the blocks were already here from the previous owner.  Otherwise I wouldn't attempt to use such heavy blocks.  I would be surprised if you can get any movement by tapping a block that size with a rubber hammer.  Even if the blocks are hosed down first I would imagine it will suck the moisture out of the mortar pretty quickly.  Do the professionals have any tricks when laying these big blocks?

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## jago

If you can get some sort of car engine winch they work well... I spent 4 years as a landscaper whilst at college I used to be the Yorkstone layer...  
I would wet down with water and use bondcrete on the base of each block just before you  lay on to your mud bed. Now with the rubber mallet don't use it like a tickle stick give it some welly it will make a difference, some use a choc and wooden mallet but not metal!  :2thumbsup:

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## cherub65

Use 10 mm plastic spacers to get your mortar joint uniformed.
Also look into specialised stone lifting equipment (like a clamp) will make job a lot easier

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## straydog

> Use 10 mm plastic spacers to get your mortar joint uniformed.
> Also look into specialised stone lifting equipment (like a clamp) will make job a lot easier

  Can you buy these spacers?

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## cherub65

we get them from local tool store, (dont pay this much for them)
here is a link https://www.multifixings.com.au/cate...atid=2&scid=18

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## paul62

Just finished a big retaining wall out the front 5 blocks high, using 500x350x260 reconstituted blocks. Found 20 mm joints  look the best. I used electrical conduit cut into 4 to 5 inch lengths. Gives a uniform gap and you can roll the block on them to adjust vertical joints. Made the job easy...

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## Brickie

> I've done a fair bit of brick laying but with bricks you just tap the brick down with the trowel until its at the correct height.

  Tap them down? What are you, a blacksmith?
No half decent bricklayer taps them down, ever.  :Doh:

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## myla

hi, 
you may be best to use like an epoxy grout to "stick" the blocks together with 10mm packers to give the height and then point with mortar mix 
just finished bluestone steps at Melb Uni in very tight location, attached beam onto quickstage scaff and block & tackle slid on this, bluestones were about the same size as your blocks
thanks

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