How can I repair these lbc bricks??

[Webbers]

Hi I am new to this forum,
I've just moved to a new house and as you can see in the pictures the bricks look damp about 50cm up the wall at the front and the back and they are covered with rock hard grey salt crystals? It looks a mess and the faces are blowing off. The damp course all the way round looks fine and the inside I the house is not damp. Does anyone have any ideas how the water might be getting past the damp course or could the salts be attracting the damp? Also how can I get rid of the grey salts I have tested brick acid and it won't touch it. Don't know what else to try. Thanks

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• Webbers
• 3 Mar 2013
• 1

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• Webbers
• 3 Mar 2013
• 1

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• Webbers
• 3 Mar 2013
• 1

 

[noseall]

I would address the issue of water present before anything else.

There looks to be far too much discolouration for it to be explained away by groundwater etc. Have any of the neighbours got similar discolouration?

If not then i would thing there is a leaky pipe somewhere.

 

[Webbers]

No there not as bad but our house sits lower than the rest and I have been told that water sits about 3 inch on the drive when it rains heavy. I'm gonna try and dig a soakaway in the back garden but was to restore the bricks if its possible

 

[joe-90]

Nosey is right. A brick acid cleaner will take off the limescale.

 

[^woody^]

It looks like you have either a high water table or poor draining ground and the water is soaking up the wall. That pattern is indicative of a blocked cavity which is allowing water up past the DPC too.

London bricks are very prone to salt release when soaked.

You need to knock a few bricks out to investigate the cavity, and clean it as necessary

Once the cavity is corrected, I doubt that you will ever remove the damp from below the DPC, or the salt stains

 

[Webbers]

Thanks for the replies...I've been told that cavity wall insulation was installed in 2009, could this be soaking up the water and breaching the dpc? And yes the ground is just clay. I'm struggling to find a way to drain it.

 

[JohnD]

Has somebody blocked that airbrick with silicone?

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• Webbers
• 3 Mar 2013
• 1

Where does the airbrick go?

Is the ground floor wood or concrete?

Have you got a water meter? I think you've got a leak.

 

[Webbers]

I was told they were blocked up because the cavity has been filled so its no longer required. The floor inside is concrete. No there isn't a water meter. But the ground never looks wet. I might get a builder to change a couple of the blown bricks and see what is behind. Is this a big job?

 

[JohnD]

With a concrete ground floor, the pattern looks to me like you have a water leak making the slab wet. How old is the plumbing?

Have a look under the flooring. Drill a hole through one of the bricks and see if the brick and concrete are wet.

 

[Webbers]

The plumbing is from the early 70s when place was built but the only only pipe in the concrete floor is the mains in with is a copper pipe coming out of the floor in the bathroom, which is halfway down that wall. Is there any way to tell if water is leaking into the cavity without removing a brick?

 

[JohnD]

drill a hole.

 

[Hugh Jaleak]

Concrete will corrode a copper pipe if the pipe was not adequately protected when installed. I had one leak under the utility room floor, despite pipe being sleeved on installation, and that was only after about 7 years.... Pipe was extremely brittle when removed, whole lot been replaced with plastic now, through a duct. Giveaway that something was leaking was the mushrooms growing out the wall above the DPC!

 

[Webbers]

I've just checked the pipe and it is actually plastic but I suppose it could still be damaged...would you expect the floor and the walls to be wet inside? I have removed the bath panel close to where the water pipe comes out and it is dry as a bone. Could damp creep about a dpc without it been breached?

 

[JohnD]

Drill a hole.

 

[^woody^]

It highly unlikely, impossibly almost for that to be via a leaking water pipe.

The type of cavity construction would mean that the inner slab would not transmit water to the outer wall without it being blatantly obviously damp on the inside wall and floor

The evenness of the dampness is from water being soaked up from the ground

Just because cavity wall insulation was installed, does not mean that the cavity was not blocked already

What is it like on the other two elevations?