Damp Issue - Buying a new property

[silverchloride]

Hi everyone, I'm new here and new to DIY! Been reading the really useful insights. I have recently put in an offer on (which has been accepted) on an end terrace house in North Yorkshire. One of the issues identified has been damp. I got a reasonable deal on the property and am expecting to spend money on renovating it (new bathroom, kitchen, garden, and general refurbishments) but I am a bit concerned about how much this damp issue will cost me.

While there is visible damp in the property, its not awful (atleast to the bare eyes) considering the property has been empty for 5-6 months, its still in not a bad shape...

I was reading here that the 999 readings are not always super reliable and was wondering if there could be a mix of DIY stuff I could do myself and specialist intervention to get this sorted. Attaching the pictures of the damp report which was prepared too.

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The report highlights extensive issues with moisture ingress at various elevations and internal walls. Here are the key points that the report suggested:

External Repairs & Water Management:​

• Full re-pointing of all external elevations to prevent water entry.
• Installing liquid DPC (Damp Proof Course) treatments around all elevations—this is a flexible, liquid membrane barrier to stop rising damp.
• Addressing drainage issues, including installing gravel or French drains, especially in areas where the property or driveway is higher than the DPC (which risks water damming against walls).
• Relocate vents with suitable air bricks to improve ventilation.
• Cut back bushes and remove debris or water Bowser close to the building to improve drainage and airflow.

Internal Wall & Structural Treatments:​

• Removing damp or damaged plaster in affected rooms (e.g., bathrooms, kitchen, living rooms, stairwalls).
• Installing membrane boards and skimming over walls after hacking back loose plaster—this acts as a barrier against residual damp and improves internal dryness.
• Treating internal damp patches with salt neutralisers.
• Replacing skirting boards, coving, and making good plaster finishes.

Windows & Doors:​

• External resealing all around window and door frames with weatherproof sealant.

Specific Areas:​

• Chimney breast needs hacking off, skimming, venting for condensation, and replacing skirting.
• Loft needs re-insulation (adding about 150mm extra) and removal of potential bird infestation.
• Kitchen walls show damp at the rear, needing plaster removal and treatment.

Observations:​

• Significant damp patches at high levels and on internal walls.
• External elevations have been identified as vulnerable due to water pooling or higher ground than DPC.
• The property’s brickwork and plaster are deteriorating in several areas, risking further damage if untreated.
• Overall, urgent damp-proofing and external drainage improvements are needed to prevent ongoing moisture ingress.

Keen to hear more on your experiences and whether this is going to cost me an arm and a leg! Thanks in advance for your assistance

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[endecotp]

Report is illiterate, not a great impression!

Don’t rush to do anything. (But at the same time, don’t do other works e.g. internal decoration until more invasive damp works have been done.)

Talk to your neighbours. Why is the party wall damp?

 

[JohnD]

I may have missed it, but why do you think the original DPC is not working?

What is its height, compared to current ground or paving level?

Are the ground floors all concrete? Were the original floors?

Which of the gutters, downpipes, gullies and drains are cracked or blocked and leaking? Chemical injections will not repair them. Clay gullies and underground drains are usually broken if they were installed before 1945.

Water pipes commonly leak after 60 to 100 years. How old are yours? Are they lead, iron, copper or plastic?

Apart from leaks and gutters, which you can repair, is there a source of water in or beside your house? Like a stream, pond, water running down a hill, or high water table?

 

[silverchloride]

Thanks - really useful points. I am very new to the world of DIY so will learn along the way while I restore this property. I think the gutters, pipes and gullies would be a good starting point - the property is more than a 100 years old - end of terrace house. Need to speak to the neighbors about the damp especially with the party wall.

The house was previously an HMO (house in multiple occupation) let out by a housing association. I think it has been empty since December 2024. The vendor is a charity/association so there's been very limited information in terms of past remedial works. Only this damp survey, which I think was why the property took a while to sell. I do love the location and the potential it has - its a decent end of corner terrace plot and a nice cosy 2 bedroom place - I'm bracing myself for the refurb costs, but before any beautification / cosmetic updates are made, I have to ensure the damp issue is resolved for good.The property did have a fairly new albeit basic quality kitchen put up (which I'll have to strip out too) but apparently, there's damp behind it too. Attaching some further pictures from the report - for advice and guidance. Thanks again, really appreciate it.

There are no water sources near the house. The property

it.

 

[Scally-Ho]

I am not condemning liquid DPC, but in my experience it is seldom 100% successful and tends to fail rather quickly. I would never trust it for any of my rental properties or recommend it to any friends or family.

 

[JohnD]

Liquid DPC will not repair any of the defects causing the damp.

A "damp meter" measures electrical resistance. It can be accurate on damp wood, but is not accurate on brickwork because it is influenced by mineral content.

The illiterate person who composed the report mentions ground and paving being above the DPC. Most likely it is slate DPC. Slate lasts about 150 million years and does not wear out, but ignorant buffoons commonly heap earth and concrete against walls to bridge over it so the wall can be made wet.

The correct and uncomplicated action is to break up the paving and dig out the earth to reduce ground level back to where it was when the house was built, which will be two or more courses of brick below the DPC. While digging, expose the gullies and the foot of soil and waste pipes, you can expect to find them broken and leaking, usually at the gullies and where the underground clay pipes have their first bend from vertical to horizontal. Usually you will find mortar poultice and additional concrete has been placed in a futile attempt to cover up (it does not cure) the leaks.

you can expect to find the water supply pipe is leaking under the house. Now is a good time to lay a new, larger plastic pipe all the way to the pavement. Once you have learned to handle a spade it is not difficult. This is a DIY site and you can do that. Did you reply about concrete floors?

Do not waste time and money on chemical treatment. It's main purpose is to enrich contractors while giving homeowners tge impression that something is being done.

Repair the sources of damp first. There is no point doing anything else until that is done.

You will not need waterproof plasters, but once you have repaired the source of water, hacking off the old wet plaster will allow the brickwork to dry out.

 

[endecotp]

I think the gutters, pipes and gullies would be a good starting point

Have a really good at the gutters look next time it pours with rain. Binoculars help.

Question is, can any gutter repairs be done from a ladder or is scaffolding needed? If you do need scaf, wait until you know about any roof, wall or upstairs window works so you can do it all at once.

As others have said, you need to understand any issues with raised ground levels and the old damp proof course. Again looking at neighbouring properties might help.

 

[JohnD]

The front wall looks particularly wet around the downpipe. To my eye the wet starts quite high up the wall, as it would if it was spilling out at the top, or if there was a blockage and it was escaping from a joint (downpipe joints are deliberately not sealed, so that, in the event of a blockage, water can escape at the next higher joint)

The front paving is also very wet.

You could put an overflow hosepipe on the water butt that runs out over the garden, as far from the house as possible, until you are sure the gulley is not at fault.

The eaves overhang looks to me rather wide, so rain will not easily get to the walls unless there is a fault.

 

[silverchloride]

Thanks everyone - very useful insights and it gives me some really good directions to start with once I have the keys. I also looked around and got a quote from an independent damp specialist:

Would love your thoughts on whether this would be worth it for £400? The plan for me is to rip the garden and re-do it anyway so there could be any leaks, etc I find there which is affecting the front elevation as well as checking out the gutters, downpipe, etc... So I'd probably start with that and tidy up everything and then see if I can find any immediate sources of this damp.

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For a survey to be conducted upon the property the cost will be £320 plus an additional £80 for the written report. The report will outline our findings with picture evidence and conclude with our suggestions to remedy the situation. We will start within the loft (if accessible) checking the brickwork, timbers and insulation level. We will then work through the rooms taking atmospheric readings, wall temperatures and moisture meter readings of all walls/floors. When an elevated reading is recorded, we will find the source/cause. Once outside a full examination of the property will take place, looking for any areas where moisture maybe ingressing into the home. We have a telescopic pole/camera which we use to check the chimneys (if you have any) roof, gutters and pointing. We will use a wide range of tools to complete the survey including a tramex moisture meter, thermal imaging camera, pole and camera to view the whole of the outside of the home, inspection borescope, concrete moisture encounter, handheld pressure washer to see how water maybe ingressing inside the home and atmospheric reader. The above equipment will be used when and where necessary.

We are totally independent surveyors meaning you will get an honest and accurate understanding of the cause of any issues found on the day.

 

[JohnD]

A survey by a qualified person who is not hoping to sell you anything, is worth more than one by a company who hopes to sell you damp oil and new plaster.

 

[endecotp]

You’ve already got a report from a “damp specialist’, haven’t you?

 

[silverchloride]

You’ve already got a report from a “damp specialist’, haven’t you?

Apparently it was from a 'builder' which usually means they want to sell you their services by recommending all sorts of things you should do! I basically bought this property off an auction so there was very limited information. In Scotland there's usually a home report and valuation but in England (and in this case) I just got sent a bunch of documents, asbestos survey, damp report and other bits... I guess I'll have to do a deep dive to really find out what the issues are. The property remained unsold on auction a few times, but I'm bracing myself for investing and bringing it back to life as the location is great, the plot size is lovely and it can have good long-term growth. Fingers crossed!

 

[endecotp]

they want to sell you their services by recommending all sorts of things you should do!

Sounds like the definition of a “damp specialist” to me.