Repointing - Mortar question

[Temmy]

Hey folks,

New person here. Hope you're all keeping safe and well during these unusual times.

I thought I'd have a go learning & practicing repointing the brickwork in my garage as a little ongoing project. The joke is the guy who built it (old owner of the house) only had a 6 inch level when he put it up... I'm unsure though what sort of mortar mix I should be going for though. My understanding is the mix should match the exisiting mortar type, is that correct?

Any chance someone can help guide me to identify what would be best?

Here's the existing brickwork (external)

And inside;

Thanks,
P

 

[CBW]

Hello,

When I'm patching up I use a 3:1 or 4:1 mix, however for re-pointing and a project it's probably better 4:1. You need to remove some of the old mix I believe.

Check out this website which I've found useful, should link to pointing brickwork and there's a YouTube video.

https://www.fixmyroof.co.uk/mix-cement-mortar/

 

[^woody^]

That is a sharp sand mortar mix with grit in it. It should be rock hard.

Normally mortar is soft building sand, so you wont match it unless you get some similar sharp gritted sand - in which case you will have great difficulty pointing with it as it will just slide off your trowel onto the floor.

 

[Temmy]

That is a sharp sand mortar mix with grit in it. It should be rock hard.

Normally mortar is soft building sand, so you wont match it unless you get some similar sharp gritted sand - in which case you will have great difficulty pointing with it as it will just slide off your trowel onto the floor.

Just the sort of observation I was looking for. Thanks woody, and yes, I think you're spot on - had a Openreach engineer around last year installing some new cable and he was complaining how impossible it was hammering cable pins into the mortar.

I'd still like to give repointing ago - just to learn and practice really. So I won't worry about matching and go for something more general.

Ta!

 

[^woody^]

Look for a yellow sand then, or red building sand with a buff dye, or a mix of red building and plastering sand. Otherwise it will stand out quite a bit.

An once pointed and its started to dry, rub over it with a block of wood or lightly with a rolled up paper bad or cloth, and this will roughen the surface up. Then brush it.

 

[Temmy]

@^woody^ Actually, I was planning to paint over it afterwards so I guess that makes things even easier!

 

[stuart45]

If you are going to paint it you may as well just bag rub it.

 

[John D v2.0]

we raked out and repointed with sharp sand and hydralic lime which wasn't too bad to apply, this was on a decorative section of wall under the bay window with ridiculously soft bricks. It produced a very light colour mortar though, but we painted after anyway.

 

[noseall]

If you are going to paint it you may as well just bag rub it.

Bag rubbed..

Corbel1

• noseall
• 21 Feb 2019

 

[stuart45]

Nice looking piece of bag rubbed brickwork. Are they Tumbled bricks?
I've noticed that churches always seem to use a flush joint.

 

[noseall]

Are they Tumbled bricks?

'Oast Russets'.

They have a distinctive shape where one arris sticks out further than t'uther, as if the brick mould allowed it to bell out at the bottom slightly - hence the bag rub.

 

[23vc]

Given you’re painting it, and it only looks like a few small gaps that need filling, I doubt the “matching existing mortar type” matters.

 

[Temmy]

Hey folks,

Got the raking point on the grinder sorted. Works great. Nearly all set to do some repointing, just one last thing to sort out, the mortar!

For a first timer, is it worth using a pre-mix mortar like this, or, is it better to make from scratch?

 

[23vc]

Make from scratch

 

[Temmy]

Make from scratch

Yeah, I think you're right. There'll be a whole lot of useful learning doing that!