Survey saying damp in some walls

[HelpNeededBeforeIHaveABreakdown]

We are selling, survey came back saying there was some damp and recommended a damp report. This has been done and recommends chemical damp proofing and re plaster to 1m height...

We have not had issues with damp and from what I read chemical damp proofing has been discredited particularly in older properties. Damp was diagnosed with handheld meter which seems to contravene British Standards. Anyone got experience of this? Do I disagree with report or suck up potential drop in price and have buyer undertake work that isn't necessary or may put them off altogether!

British standard- BS 6576: Code of practice for diagnosing rising damp in walls and buildings and installation of damp-proof courses, says; ‘Electrical moisture meter…Surface measurements cannot alone give proof of rising damp, so further evidence may, where permitted, be obtained by…measurements taken within the depth of the wall. Chemical (carbide) or gravimetric methods can be used.’
British Standard –– BS 5250: Code of practice for controlling condensation in buildings, says; ‘Accurate measurements of the moisture content of brick or mortar cannot be obtained by the use of electrical moisture meters because the presence of salts increases the electrical conductance of the water, giving falsely high readings. Gravimetric methods carried out on samples taken from the fabric give the most reliable results. The use of chemical (carbide) absorption type moisture meters will give a result in a short space of time and are almost as reliable.’

Oh gods, this again- I feel for you. Electrical moisture meters are indeed a waste of space in this context. IMO surveyors ought not to use them.
With this house, they were used by a 'damp proofing company' and they said virtually all the walls had damp and recommended all the stuff you have been (DO NOT HAVE ANY OF THAT DONE). It sounded like crap to me. So we ignored it.
After we bought the house, we had a proper job done by a qualified specialist surveyor and the walls drilled and samples taken, as per your quote above. There was some actual damp in a small section of one wall. And that's it. His remedy, get rid of the waterproof layer on the plaster some idiot had put on, because that was causing it. We did, the damp dried out, 3 years later, it's never come back. The other damp he found was all superficial and down to condensation, it was, in fact, already drying out by the time he came. Ventilation, clearing undefloor vents, removing an old gas fire, and stripping off the wallpaper and putting on breathable paint cleared everything up- making the slightly soft wallpaper at skirting height so dry that it became murder to strip!
(This house is not suitable for wallpaper, it has lime plaster walls).
You don't even have any evidence of damp!
Read Heritage House's website, they explain it all very well.

Who did the damp report?
Your problem is convincing the buyers there isn’t a problem, when the survey says there is.
Whether you can convince them to continue at the current value, or you have to give a bit on the price, do not get into doing any remedial work!
If they insist on a small/reasonable reduction you may have to suck it up.

Damp can be caused by several things. Leaking pipes/guttering , damp proof course covered up or gone, walls not breathing (as described above) and condensation on walls because they are cold. Single skin brickwork is more prone to damp and cavity walls are better. So you need to ascertain why it’s damp and find out what can be done. Obviously this surveyor is useless.

Check dpc, wall coverings, water ingress from gutterings etc. Plus adequate heating!

Sorry: adequate heating and ventilation. Ventilation is most important.

Thanks for all the info, I have looked at historic houses, they seem great, very direct in their opinions! In Scotland so home report noted damp and we had to get damp survey done ( by a recommended company). There is little to no damp. I suspect concrete floor is allowing some damp to reach walls but not causing a problem and no need for chemical damp proofing course.

How do I find qualified specialist surveyor?

DPCs are not chemical. They are vinyl or slate traditionally. Is the floor dry?

I would look at local surveyors web sites. Look for RICS members and what the firms say they do. Damp advice would not be unusual.