repointing 1978 house

[ajrobb]

I have just taken back possession of a 1978 end terrace. In the last 10 years, despite letting agent's annual inspections, the mortar has badly eroded (with holes I'd need to probe to tell how deep they are). I can scrape away the surface of the mortar with my fingers. Pretty much the whole house is affected so I'll just do the whole lot. I've owned the house since it was 2 years old and the original finish was hollow key.

Given the position on the south coast downland is fairly exposed, could I just use Wickes brick laying mortar or should I go for something a bit stronger?

 

[andyb30]

wicks bricklaying mortar is 1 to 6 i think and would not be strong enough.
you need to use 1 to 3 or 1 to 4.

 

[ajrobb]

I don't trust my trowel work not to leave a mess on the bricks. I might use a Screwfix mortar gun and go for a 3:1 mix of sand and cement. I'll start at the bottom and do what I can from a platform. Only after I get up to speed will I get scaffolding up (£££).

What sand should I use? Others have mentioned soft sand with a mortar gun. Is there much advantage in using washed and dried sand? I know it's supposed to have less salt to leach out and doesn't change weight, so the mix stays constant and doesn't change colour as the work progresses.

For a 3:1 mix, how much sand and cement will I need for 70sqm brickwork with 10mm mortar raked out to 25mm?

 

[andyb30]

i use a pointmaster gun,big yellow piston type,they hold more mortar and you dont get hand ache from the constant pumping of a caulking type gun.
to get a good flowing run and to make sure it fills to void properly it needs to be made quite wet,a bit like readybrek,so do it on a fairly dry day.with it been 1 to 3 youll need to do half a sm then point it up with your tool and so on,i say this because if you do too much it gets hard to point and after a while it kills your hands.

in my opinion id only use building sand but i can honostly say i dont really know what results would be from using another type,ive never done it or seen it done.

weve just finished a 90sm house and used 4 bags cement and 12 bags of building sand all got from wicks.

 

[alittlerespect]

Hi

Check out 'www.easipoint.co.uk'

Doesn't get any simpler and does what is say's - only hard bit is getting to and removing the existing mortar!

Regards

 

[amwc]

I think the easipoint mortars have chemicals in them to make it pump through the gun easier i.e. not seperate and in my opinion if you do not have a steady hand and get overspill onto the bricks you have a real job getting it off once it goes off, its like grout. Its good stuff once its set if you know how to use it and the pre mixed bags are excellent just add water.

 

[alittlerespect]

Well!

I would just like to state the fact that I have used the system to great effect! And you would not believe how simple it is to use - knocks spots off trying to hand point with sand and cement mortar which possibly justify's spending the extra money - just read the instructions on how to mix the material twice and you are ready to rock n roll! And yes the material comes out a lovely creamy consistency, starts setting in no time and can be pointed-in as works proceed, and there is no mess!! Not that I ever encountered!

Travis Perkins used to sell the gun and mortar mix, but I cannot say for certain that they still do, and you would have to do a search for stockists.

Only issue worth considering is buying bags of the mortar mix from the same batch number, otherwise you may find slightly different tones developing in the finished job!

Regards

 

[amwc]

All I was saying is its as easy to make a mess as it is a nice job, and a mess with easipoint mortar can be harder to shift than ordinary mortar. Just a warning from someone who uses it a lot. I really like the stuff but once its in there its staying in there. and a dust mask when mixing is a really good idea.

 

[ajrobb]

The original 1978 mortar used by Wimpey seems very weak. I am concerned that repointing with 3:1 will be too strong and crack the bricks by differential expansion and/or cause spalling by inhibiting evaporation. The bricks are none too strong by the look of it. Now, for older houses with lime mortar, a stronger lime mortar is used for pointing.

What happens if lime mortar is used to repoint cement mortar brickwork?

 

[stuart45]

I would use a 6/1/1 or 5/1/1 mix to repoint. Hod carriers often got the mix wrong or old cement was used. Anaylsis of cement mortars on site has shown it to be as weak as 20/1 in some cases.
Generally with repointing you are looking to match what the original mix was as long as it lasted for 50 years or more.
Every one you talk to will probably tell you a different mix for pointing. When I was at Tech we were taught to use 3/1 but now this is reckoned to be too strong for many jobs.
The problem is that it can take 20 years to discover that a mix was unsuitable and in that time a few generations of apprentices have been taught something which they will continue to use and teach others.