Help - crack in external brickwork of my house

[sedm]

Hello,
I have recently noticed a crack in the outside wall of our house.
It appears to run along the mortar lines of the bricks (the brick work is pretty old).
We also have some damp patches that appear on the inside wall in heavy rain (which I am wondering if this is penetrating damp coming in through the crack.)

How serious is this and how can I go about fixing it?

Thanks in advance for any advice (sorry the pic is the wrong way up!)

Crack in outside wall

• sedm
• 20 Feb 2014
• 1

 

[freethinker]

Hi,
Looking at you're picture it would appear to be a solid wall as I can see headers, however, sometimes this is not the case and it may be a cavity wall with headers to make it appear to be a solid wall. Looking at the cracks they don't appear to be new, so I wouldn't worry unduly. Your best course of action would be to monitor them to see if they are getting wider. If they are getting wider or longer then you may have to take action. If its a solid wall, which it probably is, the water may be striking through at the crack, you can seal the open joint by pointing with mortar and apply a diffusible coating such as Isonit to the wall which should prevent damp striking through.

 

[ree]

As above but i should clean out the crack(s) and fill with a top class caulking. Caulk works better if its a thermal crack.

If it is a cavity wall then the two stone lintels in place wont have cavity trays.

What purpose is the air brick serving? Is there a corresponding interior vent?

Pics of the entire elevation, and the interior water damage might help.

 

[Flyboytim]

Typical yellow London stock bricks, solid or with snapped headers and possibly with a clinker block internal skin, with no appreciable cavity.

Weatherstruck pointed in later years with strong cement mortar.

Almost all the cracking appears to be in the vertical mortar courses, the crack may proceed up (out of picture) to the lower right corner of a window above. This may be the origin of the cracking. The brickwork to the right of the crack looks darker in the photo - is it damp? Several of the original stretcher bricks have snapped and pointed up to look like several headers in a row.

The concrete lintels and original cast iron downpipe point to between the wars construction. Is the house ex-council? Which borough?

The UPVC window in the shot looks like it may be set forward on the outer brick leaf, so the crack may have originated many years ago when the original wooden or Crittall Hope windows were replaced.

The windows may have been replaced more than once over the years.

The crack appears to have been repaired several times, so cement mortar is not the answer, as weathering has popped the hard mortar out, damaging the brick edges and corners.

A flexible caulk has been suggested. If the crack is raked out and the polyurethane caulk applied thoroughly from the very top to bottom, the crack will be sealed and waterproofed.

Whether that treatment, or a sufficiently weak hydraulic lime replacement mortar as the wall was originally built with, will be better in the long run is a matter for conjecture.

 

[sedm]

Thanks so much for all your help - it has put my mind at rest.

Ree - Bizarrely there doesn't seem to be anything corresponding to the airbrick inside the house, so I can't see it's serving any purpose.

Flyboytim - Impressive, you've got it spot on. It is an ex-local authority house in the London borough of Southwark.
The windows have definitely been replaced recently (just before we bought it - and not very well, I am going to try and reseal them because I think damp is coming in around the upvc window.)

I don't think the bricks are noticeably darker on the right - it may just be the photo.

 

[sedm]

Here are some additional images of the outside (our garden is small so I can't get further back to take the entire wall) and of the damp coming in (it's mainly around the window but there are some other patches - only after heavy rain)

Untitled

• sedm
• 21 Feb 2014
• 1

Untitled

• sedm
• 21 Feb 2014
• 1

Untitled

• sedm
• 21 Feb 2014
• 1

 

[ree]

On the RH reveal of the window opening you have some kind of trim, maybe PVC or wood. Check that this trim piece is caulked on both edges - perhaps re-new the caulk?

Do the same to where the base rail, and head rail, of the PVC frame meets the stone cill and lintel.

Higher up the wall the crack appears to wander to the left or there is a parallel crack? Difficult to tell with the slant of the sunlight.

 

[ban-all-sheds]

sorry the pic is the wrong way up!

http://www.google.co.uk/search?q=free+image+editing+software

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