Wet Water / Tidal Line On Wall

A wavy tide Mark is the classic sign of rising damp. I'm surprised that the plaster was never mentioned as we very rarely leave it in place. The fact is wasn't mentioned leaves me minded to think that the injection may be suspect as well. In truth despite what the chemical companies tell us, the injection of a Chem dpc, usually a cream now, is only mostly effective, not totally. The Plastering associated with the dpc is paramount and IMHO most failures and problems are down to poor weak mix remedial Plastering. We put two extremely strong water proofer in our traditional mix, along with a salt retardant, and lots of it. When issuing long term warranties (that you intend being around to honour which many aren't BTW) leaving the plaster in place, for us isn't an option except in very rare cases. Not that we don't get asked too often. That quick fix of whipping the skirting off and just injecting, without all the mess and extra cost is so seductive, many customers beg us to do that even when they are told it won't work. It's also easy money for the unscrupulous firm prepared to do that. Hope that helps and best of luck. Phil Owen Owen preservation

Really they should of hacked the plaster off 1m higher and 300mm past the last sight of damp. They should of put a sika waterproofing render on the was wall and salt retardant in the mix. Then after that is done it should be multi finished to finish the job off.

I never rely on chancing stuff I would of recommend tanking 750 higher than the damp line and chasing the tanking as wide as you possibly can because if you are only tank one corner of your house your only chasing water away so far unless your house in a banking house should be fine So I would of hacked Antisulifate Leave for 24hrs antisulfate wall again depending on surface coat of 4.1 scratch coat 2/3 coats of tanking up the walls down on to the float then top it of with renderlite and then plaster finish to how you like

The internal plaster should be removed to the height of 1m and 500mm each side at least, but all depends how damp the whole bay is so could be more. I 100% recommend removing brickwork internally where wall cavities are preasent after removing the wall plaster and checking and clearing any debris below the original internal DPC. Any debris in the cavity will cause a bridge where moisture can transfer onto the in brickwork. Also installed cavity wall insulation can cause a bridge aswell if it has become damp. Install a new chemical DPC if required but not always required, Apply a neat coat of SBR to the brick work , render coat of sovereign antisulphate ready render, top coat of multi finish. Job done