Repointing a brick wall do i use a gun?

Dom29

Hi all the back wall needed repointing and to cut a long story short i raked it out and i guy who i know repointed it.

Im also in the process of injecting the wall with dryzone so ive had to drill into the mortar course to find that the mortar is around 1-2 cm thick covering maybe 30% of the top of the brick on the front. im guessing this is completely wrong?

So im planning on raking it out and doing it again myself and building it back out using a gun for the depth to get places and then using a pointing tool to smooth the front off. are the guns decent ? or is what hes done enough ?

Thanks in advance.

Hoploz

The way I understand pointing is that it's only on the surface, and the purpose of doing it is to create a sealed outer surface to prevent weather or creepy crawlies or whatever coming in through the cracks between the brickwork.

Furts

I do not understand what you are saying. What depth did you rake out to? I assume not deeper than 25mm?

25mm rake out would be plenty, 20mm should be OK. Hence this is the depth that the bricklayer will re-point, and then tool up the surface.

Repointing is only to protect the existing mortar, and also the edges of the bricks from frost damage. It is a weak mix, and can hardly be called structural.

cyclonebri1

Furts wrote: »

I do not understand what you are saying. What depth did you rake out to? I assume not deeper than 25mm?

25mm rake out would be plenty, 20mm should be OK. Hence this is the depth that the bricklayer will re-point, and then tool up the surface.

Repointing is only to protect the existing mortar, and also the edges of the bricks from frost damage. It is a weak mix, and can hardly be called structural.

Listen to this guy, :T:T,you rake out, chisel, angle grinder rake to say max 25mm. this will last 25 years if done right.

The important bit is the pointing needs compressing or polishing, ie, you offer a weather resistant surface to the elements, it's not difficult chap,

teneighty

cyclonebri1 wrote: »

The important bit is the pointing needs compressing or polishing, ie, you offer a weather resistant surface to the elements, it's not difficult chap,

Please don't do this. If you "polish" or over tool the face of the pointing it can trap moisture which can only evaporate out through the face of the brick, ultimately causing the face of the brick to spall.

The common mistake is to make the mortar for re-pointing too strong/hard (too much cement). As Furts suggested it should be a fairly weak mix and for pointing quite dry, usually something like a 1:1:6.

I've tried a pointing gun and they do not work with a weak dry mix as the mortar will not "flow" so you end up using a mix that is far too strong and far too wet. With a bit of practice the traditional method is far better if rather more time consuming.

cyclonebri1

teneighty wrote: »

Please don't do this. If you "polish" or over tool the face of the pointing it can trap moisture which can only evaporate out through the face of the brick, ultimately causing the face of the brick to spall.

The common mistake is to make the mortar for re-pointing too strong/hard (too much cement). As Furts suggested it should be a fairly weak mix and for pointing quite dry, usually something like a 1:1:6.

I've tried a pointing gun and they do not work with a weak dry mix as the mortar will not "flow" so you end up using a mix that is far too strong and far too wet. With a bit of practice the traditional method is far better if rather more time consuming.

The issue with over strong mortar is that the mortar doesn't give, so the brick does, BUT, this is when laying bricks, not pointing.

Pointing is a surface treatment, not a build issue No one points with a 1 to 6 mix, fine
for weak concrete but for wear resistance, wet sand is similar.

Sorry, but you are incorrect, even polishing pointing renders it more susceptible to moisture than the poorest brick facing

teneighty

cyclonebri1 wrote: »

Pointing is a surface treatment, not a build issue No one points with a 1 to 6 mix, fine
for weak concrete but for wear resistance, wet sand is similar.

Sorry, but you are incorrect, even polishing pointing renders it more susceptible to moisture than the poorest brick facing

We will have to agree to disagree on that then. 1:1:6 and 1:1:5 is the class (iii) mortar designated for moderate exposure in the British Standards for as long as I can remember and the latest Eurocode, but what do they know.

Out of interest what is your recommended mortar mix for repointing? I could do with a laugh.

cyclonebri1

teneighty wrote: »

We will have to agree to disagree on that then. 1:1:6 and 1:1:5 is the class (iii) mortar designated for moderate exposure in the British Standards for as long as I can remember and the latest Eurocode, but what do they know.

Out of interest what is your recommended mortar mix for repointing? I could do with a laugh.

Well have a laugh on me but first, why 1:1:6??

Are you talking lime mix?, you only do that for aesthetic match or because you are in a cons area and the council tell you too, or because you have unstable walls that have to have more flex at the loss of longevity..

And before you throw the toys out of the pram, that is my mix for rendering in conjunction with stone or yellow brick walls.

Take a look at this, the first thing that came up on google,

http://www.norfolkperiodpointing.co.uk/materials/

Laugh that off, and in reply to your question, for standard brick pointing I'd go 4:1 simple red or yellow sand mix, if that makes you laugh you need to rethink
" as long as I can remember" because your problem lies there, it comes to us all.

Silver-Surfer_2

Standard mix is five to one if you google "pointing mix".

tony6403

I use 6:1 sand/cement with a small quantity of Sika plasticiser added to the water which produces really good mortar for pointing.
Don't ,as is sometimes suggested, use washing up liquid instead of plasticiser.

cyclonebri1

Silver-Surfer wrote: »

Standard mix is five to one if you google "pointing mix".

yes it does but states very clearly that in exposed conditions this should be increased to 3;1 sand cement.

ie, you have min cost effective answer or the slightlly more expensive option if you wish it to last.

let me put this another way, given a standard house would cost no more than 50 squids in materials, give or take +1 or -1 in the ratio chart, why would you pay 2k for the same job given equal labour costs, that will last 1/2 as long at 1:6, 1:5?///