Is drain really required for spalling brick?

[vladzie]

Please forgive my naivety but advice would be appreciated.

I have a house with exterior wall pebble dashed with facing brick at ground level (not engineering brick) A few bricks have spalled and (whole face of brick has come away not crumbled) it looked like someone had already tried to patch repair it, as there is a different coloured cement/adhesive to back of brick fallen out. I've noticed moss already growing in broken face.

There looked to be a gravel drain at wall ground junction, but having poked through it, looks like less than 1 inch gravel and then soil.

I'm assuming water is not draining anywhere and thus water rising and causing spalling.

My query is drain wise - what is cheapest solution to this? Water does not stand nor fall back to the building. There is no damp problem within house neither. Should a land drain really be dug and properly laid? is this not a little too substantal for this? Is concreting to a fall away to the path a better idea? Will this stop brick absorbing so much water?

Apologies if I've missed any information out and in my wisdom I didnt take photos on my last visit.

Any advise would be greatly appreciated.

 

[^woody^]

I doubt a drain will help

Rain is either running down the render and onto the brickwork (inadequate drip at bottom of render?), or the brickwork is just staying naturally damp from ground water

 

[Blagard]

A few bricks have spalled and (whole face of brick has come away not crumbled) it looked like someone had already tried to patch repair it, as there is a different coloured cement/adhesive to back of brick fallen out.

First of all I would not worry about it. It is a fairly common problem with bricks at low level. It is the brick that is the problem.

The remedy is simple. Either patch it up, or cut the brick out and put a new one in. If you chose to cut it out, you simply drill out the mortar joints by stitch drilling (A series of holes next to each other). That's the easy bit. Getting the new brick in without making a mess of it requires some care and attention. There is probably a thread or two about getting a new brick(s) in. I prefer to replace using a fairly dry mortar mix to avoid shrinkage. Leave the front 20mm of the joints empty and repoint normally once the packed mortar behind has gone off.

The chances are you are talking about an old imperial size brick. There are quite a few made even today. So, you should ideally get a brick out and then take it with you to get the right size and type of bricks to refit.

As for pulling the old brick out once it is loose, I usually use a couple of bits of wire from an old coat hanger. Bend about an inch at the end at 90 degrees, slide into the open joint rotate the bent bit behind the brick and pull! I have actually used the same method for pulling out block paviours, but then I was using a pair of of stainless steel wire wall ties with a smaller bent bit.

 

[vladzie]

Never thought about the drip below the render woody.

So staying naturally damp from ground water is ok?
Forgot to mention, the lower brickwork is also painted - not ideal, but its not flacking or bubbling, so not sure if its keeping any mositure in.

They want to be able to repair/ fix then paint, but if its still getting too damp then is it ok to just patch repair and leave it the way it is? its not exactly preventing it from happening again?

Also, whats your thoughts on types of breathable paint for bricks? and also for pebbledash/render My abysmal memory only extends to keim paints for sandstone...??

Thanks for your help so far guys....

 

[Blagard]

Exposed bricks in that band of below DPC but above ground need to be frost resistant. The spalling is caused by the moisture in the brick freezing. Unless you have a means of stopping the brick becoming wet through it will probably continue to spall. I don't like painting bricks generally because it does not allow the brick to "breath". I have no idea of how effective a breathable paint is, but I feel sure it will not improve that aspect of the brick and will only make it worse. Once it's done (the paint) you are generally stuck with it.

I agree with woody on the Render run-off and drip detail, If that is also a problem it will contribute to getting the brick wet through.

As I mentioned before, you can either patch up or replace. Since I have seen many patched bricks that appear to have lasted many years, that may well be the solution to you because you have them painted. If you don't get all the loose bits off before patching you leave cracks that can fill with water and they will blow again for sure.