Lime mortar pointing - yes or no?

project_c

We need to sort out the brickwork on our victorian terrace. I've been asking for quotes, and basically I'm getting 2 different opinions:

- Builder 1, cheap: "lime mortar pointing is a load of tosh, they're ripping you off, you just need to replace the broken bricks and point with cement, job done".
- Builder 2, expensive: "we use lime mortar and do everything by hand to avoid damage to bricks. Cement ruins bricks and causes water ingress".

I'm leaning towards trusting the lime mortar guys because the fact is our bricks are damaged, and the pointing is patchy, and it was done using cement, which is falling out in places.

Before I go ahead and go for the expensive option, I would appreciate some definitive advice on this - is lime the way to go, or is it 'tosh' like the first guy said?

FreeBear

I have a small area on one wall that was pointed with cement - It is cracked and falling out, unlike the rest of the wall that was originally done with lime. When I get round to it, the cement will be raked out and done with lime properly.

loyalstokie

There is the normal cement, white cement (sold as snowcrete), hydrated lime and hydraulic lime.



Hydraulic lime is what is most likely to have been used originally (and the most expensive at £20 a bag) so make sure the expensive price is for the right stuff and the white cement is simply ther for the colour.

https://www.lime-mortars.co.uk/articles/hydrated-lime-mortar


Any place where two different materials meet has the potential for cracking and parting.

Cement doesn't really cause water ingress, but it more resistant to water (but not waterproof without additives) so and moisture in the existing bricks and mortar has more difficulty leaving. If a crack forms, water will get in behind and can freeze causing it to come away, or stay in the wall and take and easier route to the inside (in an extreme case) or through the bricks.



Whatever mortar is used should be softer than the bricks.

Cement could be ok, but can also stand out because of the colour difference.

Apodemus

You should look on the pointing as a sacrificial element. If it is harder than the bricks, then the bricks will fail rather than the pointing. Lime pointing is very time-consuming, which is why it is expensive if you are paying someone else to do it. It is very therapeutic, so ideal for a slow, gradual, DIY approach.

Robby1988

Lime work is a bit of a craft & it takes time, which is why most builders aren’t interested. They want to get done & get paid as quickly as possible.

Cement is effective and cheaper but WILL cause long term damage to a traditional property. Ultimately it depends how long term your interests are in the place, use cement as it may well serve you but will cause a problem for future occupants of the house down the line.

project_c

Robby1988 wrote: »

Lime work is a bit of a craft & it takes time, which is why most builders aren’t interested. They want to get done & get paid as quickly as possible.

Cement is effective and cheaper but WILL cause long term damage to a traditional property. Ultimately it depends how long term your interests are in the place, use cement as it may well serve you but will cause a problem for future occupants of the house down the line.

Thank you for this reply, it's pretty much what I was thinking - we're there to stay so we'll go with the expensive option and get it done properly. Ultimately if bits keep falling out every year we will end up paying about the same eventually in small annual repairs, so we might as well get it done once and for good.

garrysibbald

There's a simple rule to follow. If a property is built using lime, use lime. If built in cement use cement.

We are a pointing specialist and in the past have been called upon to remove and repoint in lime a recently pointed property because the previous company had used a cement mortar and this had been picked up by a buildings surveyor.
Another area that affects price is the type of pointing finish. Flush and struck finishes will cost you more than a bucket handle finish because of the extra time and skill required. If it's not mentioned in writing you can bet you'll get the bucket handle finish even though the others are more likely to be more in keeping with the original style.

It's a job that you will only need to do once in a long while so you'd be mad not to get it done properly and then have it come back and bite you.

project_c

garrysibbald wrote: »

There's a simple rule to follow. If a property is built using lime, use lime. If built in cement use cement.

We are a pointing specialist and in the past have been called upon to remove and repoint in lime a recently pointed property because the previous company had used a cement mortar and this had been picked up by a buildings surveyor.
Another area that affects price is the type of pointing finish. Flush and struck finishes will cost you more than a bucket handle finish because of the extra time and skill required. If it's not mentioned in writing you can bet you'll get the bucket handle finish even though the others are more likely to be more in keeping with the original style.

It's a job that you will only need to do once in a long while so you'd be mad not to get it done properly and then have it come back and bite you.

Thanks - am following your advice on this one, we have 2 specialists giving us quotes now, we'll hopefully get the job booked in over the next few days.

stuart45

I'm doing a repointing job at the moment with lime (NHL 3.5/sand), on an hourly rate. The raking out and pointing does not really take any longer with lime than cement. It takes longer to mix up and is a bit more work covering it up and keeping it misted for a week or so.
The owner got Limelite NHL 3.5 for around £12 a bag from Jewsons, although you may pay a bit more in other places. Some types of NHL 3.5 go harder than others. The stuff from Portugal is not as good as the French for example.