Brick discolouration

[trevorbayliss]

I enclose a photo of some brickwork i have done on my extension.

I did them last autumn using a sand and lime mix 3:1.

The bricks look a different colour when dry, but they are not a nice colour.

Is this effervescence ?

I have just done a garden wall with these bricks and they look much better (laid in very dry conditions).

I am about to start on opposite side to this brick work and i am hoping i get a better result.

Any ideas on why this hasn't worked out so well ?

 

[^woody^]

What's the question? The patch of damp or the wall generally?

Btw, don't you think that you should have pointed the wall up when you built it? All the rain is soaking into that wall when it rains.

 

[trevorbayliss]

I did point it. I have full filled and then rubbed the pointing with a cloth. The grains in the sand come out well.

The damp patch is me spraying the wall with a hose to show the bricks are a nice colour when wet, but not as nice when dry.

I have been reading about it and i think i have lime staining.

It was damp when i laid these bricks and i think the bricks were pretty wet.

The main section of bricks need to be done this month and i have realised the bricks need to be much drier.

Can i improve these bricks appearance ?

 

[^woody^]

I did point it. I have full filled and then rubbed the pointing with a cloth. The grains in the sand come out well.

That's not pointing! Pointing is tooling the joint to give it a weathering face to keep the water out.

You have either rubbed lime all over the place with that cloth rubbing, or rain is soaking in to the wall and leeching lime or salts.

 

[trevorbayliss]

I think I have rubbed lime over the brick.

My house pointing is slightly recessed, not quite flush like this pointing. I am sure this pointing is ok though.

Normally you get the same effect when you beat lime mortar with with a stiff brush.

My wall is open at the top and has been all winter. Are you sure it is the pointing which is faulty?

I need to get some further advise before I grind out all this work then.

I will look at some new pointing tools to see if the next lot of brick work can go better.

 

[stuart45]

It's better to use a churn brush for flush pointing on lime work. You need to keep the rain off for longer than with cement work. That wall looks like it was left exposed too early and the rain has brought out some lime onto the facework where it has cured.

 

[trevorbayliss]

Yes i don't think i kept the rain off correctly. I was thinking it was ok after a few days.

I think i just need to do an acid wash later this year after i get everything built.

 

[^woody^]

Why have you even used lime on a single skin of a cavity wall and with blocks and cement mortar internally?

 

[trevorbayliss]

Because my house is lime built and i thought doing it in lime on the outside would work better in terms of looks.

With hindsight using the lime probably wasn't the best option, certainly cost me more as well and i have had the issue of not being able to work over the winter to get the other bricks done.

You live and learn, but if i did it again i would prob go for cement. I have just done my garden wall in cement and lime and it was a lot easier to work with and build.