Can I use ready gauged morter for haunching?

[Restoration man]

I am away to tidy up the haunching on a 4 pot chimney on my house. It's not terrible but there's a couple of cracked bits so I was going to cut them out with a diamond blade and redo a good 1" thickness over the whole thing.

Can I use a decent brand ready gauged morter mix for this or should I be adding some small balast to make a fine concrete?

Once mixed how long would a typical ready mix morter be usable for?

Thanks

 

[^woody^]

Mortar is too soft even if you add ballast.

Use a sharp screed sand.

Mortar for the bricks 3:1.

You'll get an hour or two usability at this time of year

 

[rick68]

Grano to dust may be ok for a bit of structure if you can get your hands on a small bag full,, As for the useable length of time for the mortar read the instructions and knock about 10 mins off for getting it up there and getting sorted out

 

[Restoration man]

Woody what do you mean mortar for the bricks?

I am only doing the very top bit round the chimney pots. The top of the chimney is a big precast slab. Then has three pieces on top of this also precast concrete.

All I'm redoing is the rounded smooth bit that helps the rain run off round the base of the pots but on top of the highest point on the chimney.

 

[rick68]

3 sand to 1 cement mix he means ,, usual mix

 

[^woody^]

Woody what do you mean mortar for the bricks?

Sorry, I misread your OP and thought you said you were also cutting out some cracked bricks, not cracked bits.

No mortar then, just a strong screed sand mix.

Also, 1" thick is not a great deal, so if you can, increase it a little. Damp the existing down, and brush on a cement slurry as a primer.

 

[Restoration man]

I get your comments on the thickness I can sort that.

So the mix should be 3 sharp sand 1 cement.

The prebagged I was going to use is Lafarge mortar mix 1 cement 1 lime and 4 sand.

Will I be able to get the 3:1 mix your saying prebagged under any name? For example screed mix?

Thanks