Mortar defect?

Brickwork have just been high pressure washed. The mortar looks very soft sandy and weak. The sands crumbles down if you run your finger on the mortar.

Here is the video https://youtu.be/rL-NTP3Pe4Q

Have everyone had the same issue and can advise what are the possible remediations? Thanks in advance.

This thread should be in Building Standards to have the best chance of it seen by the forum's professionals.

First thing to do is to check your contract to see whether there is a certified Performance Solution that allows a weaker mortar mix that will most often use more than double the sand content. A 1:1:10 specification is common in a Performance Solution.

You can get mortar mix lab analysed.

If the mortar mix has excess sand to what is allowed, raking the mortar out to 25mm and repointing is the usual solution. I would avoid chemical hardeners.

The problem could also possibly/probably be a symptom of the acid clean but getting the mortar analysed would be my recommended move after checking the contract.

We use HIA contract theres nowhere specified certified Performance Solutions.
But mortar mix 1:1:4.5 was specified in engineer notes.

Its probably a symptom of acid clean because the uncleaned mortar seems fine.

We will get the mortar analysed but If it come back within the specification, what would be the solution to fix the loose mortar damaged by acid wash?

You can't trust brickies.

There are a number of posts on Homeone about mortar and other issues after acid washing. Just do a forum search using the words "acid wash mortar" or similar to read about other's experiences.


Raking the mortar out to 25mm and repointing is best but this might be met with resistance from your builder.

Do you have an independent building consultant who has done stage inspections for you? You really need someone with industry experience onsite to assess the seriousness.