The correct material for repointing?

[MattB83]

Hi,
I was hoping to add repointing to my to-do list. I'd like to learn how to do this - starting with a small outhouse on the side of the house. I've been reading posts here and trying to work out what type of mortar I need to use.

Here are some photos - as you can see someone's done some very selective repointing at some point - literally only a few mm thick on top of the original in some places - to me this looks like a completely different material - if this is cement then this isn't great for the brickwork is it?

Appreciate any advice on what material to use:

PICS - https://photos.app.goo.gl/yncaJ1AMTmd57mgHA

If it's relevant - house was build approx in the 1950's our survey suggested.

 

[sxturbo]

Ok so you have lime mortar originally.

But some joker has attempted to do some repairs in the past and used cement.

You need to remove this and replace with hydraulic lime mortar.

Speak to a specialist lime mortar company for help and advice. There is a couple of online outlets that are very good

 

[^woody^]

Ok so you have lime mortar originally

In the 50's, and with commons?

 

[Notch7]

Wrong colour sand?

 

[MattB83]

In the 50's, and with commons?

Was lime mortar unlikely in the 50s?

 

[Deleted member 267285]

Could be fast set cement or wrong sand/cement ratio, or incorrect sand used, either way it looks harder than the brick, so would need removing imo.

 

[sxturbo]

Was lime mortar unlikely in the 50s?

No not really.

Between the 30's and 60's was the transition to cement mortar.

The 3rd pic you posted looks like lime mortar.

 

[^woody^]

The post war building boom was with predominantly cement mortar. Lime would be rare and tended to be for niche individual builds away from the new urban estates.

 

[MattB83]

Thanks all. In the absence of a clear answer, and I went ahead and pointed with lime mortar - and it wasn't lime originally, would this cause problems?

 

[johnny2007]

Just rake an inch into the joints, clean everything perfectly (hoover, then air compressor, then hoover again), spray a mist of wet water and then repoint with sand/cement/plasticizer.
Make sure it's not going to freeze, so keep an eye on the forecast.

 

[MattB83]

Just rake an inch into the joints, clean everything perfectly (hoover, then air compressor, then hoover again), spray a mist of wet water and then repoint with sand/cement/plasticizer.
Make sure it's not going to freeze, so keep an eye on the forecast.

Is an inch enough - if the mortar is in really poor condition? I think I could scrape an inch out with my finger in most places it's so crumbly.

 

[johnny2007]

Is an inch enough - if the mortar is in really poor condition? I think I could scrape an inch out with my finger in most places it's so crumbly.

Then you need a bulldozer and a few good bricklayers.
Then roofers, plumbers, electricians, etc.

 

[MattB83]

Then you need a bulldozer and a few good bricklayers.
Then roofers, plumbers, electricians, etc.

An inch it is!

 

[sxturbo]

Thanks all. In the absence of a clear answer, and I went ahead and pointed with lime mortar - and it wasn't lime originally, would this cause problems?

No it wouldn't, but if you don't the reverse it will.