Damp result on survey

[Hyperion100]

Calling @pigletjohn again!

I need your help and expertise please.

We just had the survey back on a property we're potentially buying on the east london/essex border and its come back with damp readings of 17% in a few spots on the rear and party wall.

We've lived with and tried to fix damp proplems before which was a nightmare and dont want to have to deal with those again. I dont believe the injectable DPCs work as I know multiple people who have seen them fail. (Also, peter ward on youtube has me convinced rising damp is a myth and always has a cause)

Its a 30s built semi, suspended wooden floors. Air vents front and back seem open and unobstructed.

No visible signs of bad pipework or downstairs loo.

There is a chimney breast on that party wall.

Where do I go from here? Are there any honest damp surveyors out there who are not trying to sell DPCs and tanking?

Would it be sensible to get a drainage survey now?

I apprecaite any and all advice!

Following as I have a similar situation... two out of three quotes recommending injectable DPC.

What did the 3rd quote recommend?

photos please, and a sketch plan showing where the damp patches in relation to pipes, drains and sources of water such as baths.

photos to include the damp patches, with something to show scale, and a wider view showing the entire wall all the way up to the gutter and all the way down to the paving.

A 1930's house will usually have leaking drains and/or waterpipes.

It wouldn’t be cheap but you could get an additional survey from a company that specialises in non damp proofing damp solutions. We used Hutton and Rostron and they were really thorough and impressive. Ours is timber frame, though, so a different range of issues.

@Hyperion100

What did the 3rd quote recommend?

Hi @Hyperion100 the third quote followed a visit from an established company and they suggested the damp patch we've found, inside the bifold doors at the back of the house, just needs the sub-floor timber replacing and where we've taken the skirting off (as we have new flooring going down) the plaster is currently going too far down the wall and should be chipped away to remove the bridge that it's currently forming with the sub-floor, to avoid a sponge effect. Not sure what to do as don't want to spend £££ unless it's absolutely necessary.

I've bought three houses, each in turn had minor damp problems. I've resolved all of them by....

• Checking & clearing any blocked gutters & drains.
• Checking flashing around chimneys.
• Checking seals around windows and doors.
• Digging the soil away from the foundations close to any damp patches. Expose the foundations, and check the mortar between the bricks of the foundations. If it's damp and crumbling, scrape out the old mortar in sections and repoint. If there are any badly crumbled bricks, take them out individually and replace them. More than one or two and you should really get a professional builder in.

Injected damp courses never seem to work for me either.

Is the chimney capped? Is there an air vent in the chimney breast?

@PigletJohn

photos please, and a sketch plan showing where the damp patches in relation to pipes, drains and sources of water such as baths.

photos to include the damp patches, with something to show scale, and a wider view showing the entire wall all the way up to the gutter and all the way down to the paving.

A 1930's house will usually have leaking drains and/or waterpipes.

Will try and get some pics and get back to you, thanks pigletjohn!

@Mintjulia

Is the chimney capped? Is there an air vent in the chimney breast?

Uncapped but both chimneys have been boarded over with no air vents.

Speaking to the surveyor more tomorrow.

Will keep you posted.

@Sorbustree123
" the plaster is currently going too far down the wall and should be chipped away to remove the bridge that it's currently forming with the sub-floor, to avoid a sponge effect. "

you mean the concrete floor? it should not be wet. How old is the house?

perhaps there is a leaking pipe underneath.

[quote PigletJohn]@Sorbustree123
" the plaster is currently going too far down the wall and should be chipped away to remove the bridge that it's currently forming with the sub-floor, to avoid a sponge effect. "

you mean the concrete floor? it should not be wet. How old is the house?

perhaps there is a leaking pipe underneath.[/quote]
Here's a photo @PigletJohn with a circle around the small area of rotten wood that we noticed after taking up the old flooring. New flooring has arrived, but we want to make sure we deal with this issue first before putting it down. It's a 1930s house, so suspended timber floor. The damp specialist who suggested injecting a DPC wasn't necessary, did take up a floorboards in this area and check the damp readings underneath - he did suggest replacing the damaged timber, chipping back the plaster that's coming down the wall to the sub-floor level to avoid a bridge, and also applying mastic down the side of the bifold door on the outside. Do you think this should suffice? The two other quotes (only one of which visited in person) suggested injectable DPC at a cost of £750-£850. I've tried to attach a photo.

Just wanted to add to your comment about rising damp, we were told our house had a small amount of rising damp (we were the sellers) which upon investigation turned out to be a joist fitted incorrectly by DH in the floor which had become rotten when we had a small pipe leak (we fixed the pipe a year or so before but didn’t notice the wood) so our rising damp turned out to be caused by something!

@Sorbustree123

that patch looks pretty sure to be caused by rainwater penetration from the replacement patio doors, probably incorrect detailing at the sill.

It's quite correct to have a gap between plaster and floor, but I don't believe that's relevant to the wet spot. Silicone injections would be totally useless.

[quote PigletJohn]@Sorbustree123

that patch looks pretty sure to be caused by rainwater penetration from the replacement patio doors, probably incorrect detailing at the sill.

It's quite correct to have a gap between plaster and floor, but I don't believe that's relevant to the wet spot. Silicone injections would be totally useless.[/quote]
Thank you @PigletJohn

Get a survey by an independent surveyor who specialises in old houses, not some 'dampproofing specialist' or anyone who actually does damp proofing work. The only way to correctly identify dam in a wall is to drill some of the masonry out and test it. Those prongy things are for wood, not walls, plaster or masonry, and will give inaccurate readings.
Our 'dapproofing company' survey said the whole house was damp. Proper testing after we moved in said there were only two small bits of wall that were, and not due to the cause the company had said anyway.
Go to Heritage House's website and have a read.