# Forum Home Renovation Landscaping, Gardening & Outdoors  Proper sand/cement mix for rock garden

## ecsk

All the cement in my garden,  flower bed edge, rock features, retaining wall, etc are falling apart badly, I attempted to repair some a year ago with off the shelf sand/cement mix but they came off after 2 months. 
After xmas I'm going to repair them again, but I need some advice on how to mix proper cement which can last long in outdoor, you know how strong our oz sun is  :Smilie:  
Any help will be appreciated.

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## GeoffW1

> All the cement in my garden, flower bed edge, rock features, retaining wall, etc are falling apart badly, I attempted to repair some a year ago with off the shelf sand/cement mix but they came off after 2 months. 
> After xmas I'm going to repair them again, but I need some advice on how to mix proper cement which can last long in outdoor, you know how strong our oz sun is  
> Any help will be appreciated.

  Hi, 
The conventional wisdom is to have a mix a little weaker than the background, so for sandstone bush rock you could use 1:1:6 of cement:lime:fine washed sand, or even 1:2:9.  
You might want to colour your mix, and I found between 1:30 and 1:50 of oxide:dry total mortar was good. 
I had great success with a large sealant sausage gun when mortaring, for squirting mortar mix into the joints in the bushrock structure, like this one (mine was $10 from Bunnings)  Acryloc - Render, Texture, Paint 
but you have to use the lime in the mortar, and also some Bycol or a dash of detergent, or it won't work. 
Edging strips are different, and for those you could use 1:4 cement:sand, or even concrete mix with a little more difficulty. I had success with burying a length of bricktor mesh in it, which gave it more strength in buckling. 
About your retaining wall I can't say, what is the structure of it? 
Cheers

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## Craigoss

> Hi, 
> I had great success with a large sealant sausage gun when mortaring, for squirting mortar mix into the joints in the bushrock structure, like this one (mine was $10 from Bunnings)

  Rather than use a sausage gun, there is another tool which does abit better i think. Check out the point master tool, i bought it from the Aus distributer for repointing purposes, but would be fine for landscaping jobs.  Point Master - The pointing and repointing tool for applying mortar and grout

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## GeoffW1

> Rather than use a sausage gun, there is another tool which does abit better i think. Check out the point master tool, i bought it from the Aus distributer for repointing purposes, but would be fine for landscaping jobs.  Point Master - The pointing and repointing tool for applying mortar and grout

  
Looks good. Let's have a shoot-out - mortar at 15 paces  :Clap2:

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## ecsk

> Hi, 
> The conventional wisdom is to have a mix a little weaker than the background, so for sandstone bush rock you could use 1:1:6 of cement:lime:fine washed sand, or even 1:2:9.  
> You might want to colour your mix, and I found between 1:30 and 1:50 of oxide:dry total mortar was good. 
> I had great success with a large sealant sausage gun when mortaring, for squirting mortar mix into the joints in the bushrock structure, like this one (mine was $10 from Bunnings)  Acryloc - Render, Texture, Paint 
> but you have to use the lime in the mortar, and also some Bycol or a dash of detergent, or it won't work. 
> Edging strips are different, and for those you could use 1:4 cement:sand, or even concrete mix with a little more difficulty. I had success with burying a length of bricktor mesh in it, which gave it more strength in buckling. 
> About your retaining wall I can't say, what is the structure of it? 
> Cheers

  Thanks for the info Geoff,  
I'll take some photo and show you my retaining wall. 
Cheers

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