1900 property with damp and salts

[LindaMB]

I have a late 1800s/early 1900s property, had damp readings on survey on an internal no cavity party wall where closed in fireplace, was told by damp surveyor just needs mesh membrane - I went ahead with purchase. After moving in the plaster started to spoil on bottom half of wall with salts present. I also realised it’s rendered shut at the top of chimney stack & stack is rendered, it’s closed in at bottom and not vented (which no surveyor picked up), so I had it taken back to brickwork and knocked the fireplace back out (which was very wet inside) leaving it to dry out, with a plan to then put a log burner in.

It’s been 9months and although the inside is dryer than it was it hasn’t dried out fully at the bottom, (top of chimney stack is still closed as kept getting mucked about by builder). The damp bottom of wall seems to get darker/more damp at times then lightens then darkens again, I think this could line in with when it rains. I’m stuck on what to do and conscious winter is almost here. Builders say to dry rod, damp guys say to mesh membrane or DPC cream. Then use salt neutraliser, plaster and get log burner done. Also aware I live at bottom of a hill and close to the coast, you also step down into the house so they could cause damp at bottom of wall. When I am home I have windows open. Also know the other side of the party wall my neighbour has a plastic DPC.

Not sure whether to go ahead dry rod or DOC cream or mesh membrane and get the log burner done (Hetas fireplace guy will check stack for issues when he goes to open up for log burner) so I’m all sorted for Christmas.

OR if I need I have the stack opened and capped, swept, flue put in, ready, and stack/roof checked.. then wait see if dries out, at same time get humidity readers so I can monitor the humidity in the house. - if then dries out don’t damp proof, if doesnt start to dry out damp proof - but just accept I’m probably another 6 months away from being able to enjoy my house! I read mixed things on damp proofing, and whether its bad for the wall. It’s soft brick and lime mortar. I also have concrete floor.

Also to mention, when the fireplace was knocked out, someone mucked up - and I now need bricks added back in to make back to regs, I’m not sure what materials should or shouldn’t be used when doing this or when replastering. Builders seem to want to use cement and gypsum plaster - whole house is in gypsum to be fair.

There is a second fireplace along the same wall which is also is damp in a corner.

Any advice would be appreciated as I’m so stuck! To note - it’s not my forever home and funds limited as on my own!

 

[IHateDamp]

I think anything that is going to trap moisture eg creams, membranes. impermeable plaster/render, hold back on

People are often pressured by builders to do things they later regret. Builders don't have to live with it afterwards.

People are told they have damp when their not actually seeing evidence of damp, only a high reading. It tends to induce panic mode.

This forum has taught me to do only as much as necessary. Do something and then see if it has worked for a few months before taking the next step. It's a lot cheaper that way.

Give yourself some time to soak in the knowledge of this forum so you can feel right about the next steps you chose to take.

I hope someone with more experience than me will respond.

 

[Stevers]

My basement fireplace was pretty vile, but has been completely tamed with an NHL render and finishing coat. The stone flags are well below the external ground level and the joints do go dark particularly in the summer when the heating is off, but any salting quickly stopped and it feels quite civilised down there now with some targetted trickle ventilation to make sure it stays that way.