Cracked brick

[Davem343]

I was walking around my house yesterday and noticed a cracked brick. The mortar below the brick is cracked and rather than run around the brick it moves up the wall diagonally. I'm not sure if this is due to the strength of the mortar or if there is a more serious issue with the wall?

Thanks in advance

 

[KenGMac]

Davem343, good evening.

Note this is your first post on the forum, if no one else does, Welcome.

It looks as if your external blocks are man made, Concrete, similar to Fife stone, but there are a load of similar products, all of which are made of concrete in a factory.

This material is notorious for thermal Cracking, that is especially noticeable on elevations that are exposed to a long period of time. Question is the crack you have located on an elevation that has a load of sunshine?

Next question can you if possible upload a further image of the entire wall ?

Is the crack near a door or window? such areas are regarded as "weak" especially where the crack is below a window.

Finally how old is the property? let me guess at about 1980??

Ken

 

[Davem343]

Good Evening Ken,

Many thanks for your reply, much appreciated.

My house is on a hill (bungalow on a split level built late 90's), with the wall containing the crack pointing north. It's exposed, as there is no neighbouring property to the side therefore it attracts the elements, lots of wind and rain, although given it's northerly direction not too much sun.

I've uploaded a few photo's . There is a vent near where the crack originates, however rather than run along the mortar joints there is one brick which is cracked, running into a second.

I'm not sure if this is something to be concerned about, or if I can simply repoint the mortar and place clear silicon in the bricks to protect it from moisture?

Any advice would be really appreciated.

Many thanks,
Dave

 

[KenGMac]

Davem343, good evening.

OK firstly, the cracks are nothing to be concerned about, and definitely not Subsidence ! ! !

As in my first post, the blocks are well known to shrink and expand fairly violently leading to cracking.

In most [almost all] modern property Expansion / Contraction joints are built in, vertical mastic filled joints.

Depending on the coefficient of Expansion of the blocks expansion joints can be carefully designed in to the build to a greater extent stop the mortar and blocks from cracking. That is all very well in the office but what happens in the manufacturing of the blocks, never mind what happens on site is a totally different matter??

The cracks have and are being occasioned by Thermal and moisture movement, as an aside, does the elevation containing the cracks have any built in vertical joints ?? these vertical joints can be masked by down pipes??

As for repair? If the property were mine, under NO CIRCUMSTANCES WHATSOEVER would I consider chipping out the cracked mortar which is very minor in extent why? because ---

The colour of the mortar you then re-fill the joint with will forever be different, this will attract the attention of any future buyer or the definitely un-wanted scrutiny of a [spit - spit] Valuation Surveyor who will recoil behind the dreaded Subsidence Possibility and the valuation will drop, the Valuation Surveyor is simply adhering to His / Her Liability insurance requirements.

If it were me I would use a very, very thin cut nozzle on a tube of clear mastic and insert the mastic into the cracks.

If possible do NOT smear the mastic on to the surface of the mortar or blocks, if you do, the mastic will over time dis-colour and as above draw attention to the very, very small cracks.

Hope my ramblings are making some sense?

To sum up, do not draw attention to the cracks.

Ken.

 

[Davem343]

Good Evening KenGMac,

Thanks for your reply, really appreciate the advice.

Although I am not planning on moving anytime soon, I understand your advice on the repointing. I'll take the clear mastic approach.

Thanks again for the advice.

Many thanks,
Dave

 

[KenGMac]

OK at this time I will come clean here.

I work freelance as a Subsidence Engineer for several firms.

If I need to instruct a rake out and re-point i will at all times instruct that the entire wall be raked out and re-pointed simply to ensure that some Numpty Valuation Surveyor will not run around screaming SUBSIDENCE that will devalue the property and once flagged as subsidence it is difficult to remove the stigma.

What annoys me is that valuation Surveyors see a crack and recoil to "protect" their Liability Insurances, i have seen many. many occasions of such surveys finding plasterboard cracks and calling them subsidnce, does not hold water on the third floor of a modern block of flats??

hope all goes well

Cheers.

Ken.