Reason for serial horizontal cracking?

You posted that as I was replying to a previous post.

Water in a cavity is OK (though not ideal), as long as it is below DPC, and the inner flor is protected by a DPM.
I appreciate that the whole idea of a cavity is to deal with a certain level of water ingress - so I've no problem with that. However, will that massive chunk of mortar that you see in the pic not hold water - and allow it to trickle down onto the top surface of the membrane - and from there, it will make its way inwards?
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It does not look like the mortar is actually bridging the cavity. If there is no bridge then any moisture will run down the wall. the mortar snot wont actually 'hold' water, and it wont be an issue if the mortar snot is damp

But there should not be any snots like that in the cavity, and it could potentially cause (or facilitate) moisture transfer across the cavity and the narrow areas of insulation.
Progress is slow with this - as I'm having to fit this in between other commitments (and In any event, I'm waiting on the bank to confirm that they are ok with the repairs that have been recommended - given that they have an interest in the property i.e. they're a lienholder).

Anyway, I scraped back some more 'mortar' from the space in the flooring between the screed/floor insulation and the adjoining wall blockwork inside. No sign of the dpc membrane and no sign of the dpm membrane - now that I've taken it down to the level just below the thickness/depth of the floor insulation.


- Am I right in saying that there should be membrane coming up to meet the top level of the screed OR to meet the DPC course?
- Is it correct to assume that the DPC course couldn't (or shouldn't!) be any lower than the screed level inside?
Ok, Ive either found the DPC or DPM => PIC.

Surely regardless of which one it is, there's something wrong here?

i.e. if its the DPC - then surely it shouldn't be below floor screed/floor insulation level?

if its the DPM - then it doesn't seem to be connected to any other membrane going inwards? That seems to be the end of the membrane.

Can anyone offer an opinion on this?
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Latest Instalment.

I got a plasterer/builder in. The idea was 2 fold;

1. Get a quote for the specification of repair in terms of what the insurer has offered me i.e. removal of plaster and re-plastering externally; same internally on internal surfaces facing the gable wall.

2. Discuss the practicalities of what's involved and what can be achieved in terms of remediation.

The outcome...

He won't quote me! Not in a bad way though. He first viewed the damage. His belief is that either there was too much plasticiser used in the mortar OR they used fairy liquid or the likes - resulting in the horizontal cracking.

Net result: I'm going to get a core sample taken out of one of those cracks - and send it away to a lab for analysis. I'll ask them to test for the strength and constitution of the mortar in the first instance. Whether I bother with testing the blocks themselves remains to be seen (I'll await the initial test results in the first instance. This form of testing doesn't come cheap).

As always, I will update here with the outcome. I know for those that have been following this thread that it's been a convoluted journey. It's not something that I can (or could) help. However, I believe there will be a lesson in this for all forum visitors by the time I get to sum it up and get to the root of the issue.

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