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Advice On Repointing

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22 hours ago, JohnnyBoy said:

Just had ours done and they used 4:1 sand to cement mix. I was worried after as read should use part lime and cement only mixes can be stronger than the brick and cause them to spall. Also cement traps the moisture so walls don’t breath. Had a couple builders round to quote on another groundwork job and they commented the pointing looks good and not to worry about no lime.

It was built with a 4 to 1 sand and cement ratio lime has not been used on site work for 70 years  they used to have lime pits for plastering not bwk. Lime used to make the mortar mix  more pliable thats all then along came adatives in a bottle. Bricklayers used  a drop of fairy liquid adad to a bucket water magic 

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For what its worth today’s properties have sand and cement in 5:1 or weaker mixed with additives usually called air entrainers  that provide plasticity for the user and frost proofing for life. It sets hard and brittle but works. 

 

As for repointing then I was taught by the old boys that the mix should always be weaker than what is there or it will shell off which I have witnessed. My choice of mix is sand, lime and cement in the ratio of 6:1:1 with a air entrainer added, it sets hard enough if cured right. 

 

Nothing wrong with lime mortar on the old properties, sets hard enough for any weather but also remains pliable, avoiding the problems associated with modern hard renders. 

 

In 1988 I was working on a retired clerk of works house who was 80 years old who noted my modern 5:1 sand and cement mix with air entrainer added.  He went onto tell me about buildings still stood today dotted around the City built out of lime mortar and how todays mortar is fast and convenient but not the best in the long term.  He took me down to the bottom of his garden with my brick hammer and gave me a brick probably laid over 100 years ago and the frog was full of lime mortar. He challenged me to knock it out but I failed. All I could it put dents in it, it was well stuck but not hard. If it was the modern mortar I could have hit it once and that mortar would have come out in one piece. His point was hardness comes with brittleness, but lime sticks and remains pliable. 

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  • Old bricks didnt have frogs as such frogs were in London bricks the old sheff bricks had a slight indintation in them and were 3 inch thick not a brick as seen or made today not entrainer plasticiser is the adative put in a 4to 1 mix 
Edited by spider1

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Ok not a frog but an indention. 

 

What is your opinion of a plasticiser? Mine is Feb mix and other plastisizers which are air entrainers. Thousands of minute air bubbles that act like ball bearings or so that what is what the Feb rep taught us at Shirecliffe College.  

 

Negotiable whether you add it to lime or not. Some do some don’t. I do to reduce the water content, less chance of shrinkage crazing. 

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Was a bricklayer for 50 years built houses mainly  but extentions factories on a subcontractor basis

 Never used lime but plasteries did they had a lime pit. When feb mix came  out it was brillitant so were all the other plasticisers it made the mortar a lot better to work with  / Then came ready mix in tubs think we were te first gang to use it in sheffield at fist we hated it but after a couple weeks we got used to it brillaint no mixers going round was working for dennis north at at the time

The last job we worked on was the police station on attercliffe we built the decorative bwk on the front entrance for gleeson /  As said if i do a bit these days just put a drop of fairy liquid in a bucket makes mortar a lot better to work with. Hard times on scaffold at 8am er till 5pm but finished friday 

in to pub. Only joshing you about frogs mate you may be right       All the best the Spider

 

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12 hours ago, spider1 said:

Was a bricklayer for 50 years built houses mainly  but extentions factories on a subcontractor basis

 Never used lime but plasteries did they had a lime pit. When feb mix came  out it was brillitant so were all the other plasticisers it made the mortar a lot better to work with  / Then came ready mix in tubs think we were te first gang to use it in sheffield at fist we hated it but after a couple weeks we got used to it brillaint no mixers going round was working for dennis north at at the time

The last job we worked on was the police station on attercliffe we built the decorative bwk on the front entrance for gleeson /  As said if i do a bit these days just put a drop of fairy liquid in a bucket makes mortar a lot better to work with. Hard times on scaffold at 8am er till 5pm but finished friday 

in to pub. Only joshing you about frogs mate you may be right       All the best the Spider

 

I was mainly plastering years ago but then landscaping. Retired now.

 

Dennis North? I live in one of his built 1983. That was ready mixed mortar. LBC Cotwolds. 

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8 minutes ago, GerryBooth said:

I was mainly plastering years ago but then landscaping. Retired now.

 

Dennis North? I live in one of his built 1983. That was ready mixed mortar. LBC Cotwolds. 

Yes we prob built it stannington / Outibridge . London cotswolds great bricks faces dont shell off them think they have a  grey face'  I knew dennis very well had his lad working with us a bit when we worked at outibridge he used to have us working on the church

 

Edited by spider1

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21 hours ago, spider1 said:

Was a bricklayer for 50 years built houses mainly  but extentions factories on a subcontractor basis

 Never used lime but plasteries did they had a lime pit. When feb mix came  out it was brillitant so were all the other plasticisers it made the mortar a lot better to work with  / Then came ready mix in tubs think we were te first gang to use it in sheffield at fist we hated it but after a couple weeks we got used to it brillaint no mixers going round was working for dennis north at at the time

The last job we worked on was the police station on attercliffe we built the decorative bwk on the front entrance for gleeson /  As said if i do a bit these days just put a drop of fairy liquid in a bucket makes mortar a lot better to work with. Hard times on scaffold at 8am er till 5pm but finished friday 

in to pub. Only joshing you about frogs mate you may be right       All the best the Spider

 

You can add Plasticiser to your own mix to make it weather and damp proof.

 

 

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15 minutes ago, FinBak said:

You can add Plasticiser to your own mix to make it weather and damp proof.

 

 

Yes you can but if you aint got none use fairy 

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16 minutes ago, spider1 said:

Yes you can but if you aint got none use fairy 

Ain't got none of what?

 

Fairy is for washing up.... laddy.. :hihi:

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19 minutes ago, FinBak said:

Ain't got none of what?

 

Fairy is for washing up.... laddy.. :hihi:

Now i shouldnt be telling you trade secrets

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3:1sand cement  mix I always use for repointing ground out to 20mm, joints dampened  down before pointing 

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