Damp Proofing

Semper · 2 August 2018 at 12:12AM

Good Evening,

I've recently discovered fungus and dry rot in my home with new spores appearing on some of the joists (so I need to move quickly). Looked into 4 separate firms. One isn't available for another week (Peter Cox), one local is dragging their heels with a quote, one failed to show up and the final one has almost no online presence with only 3 positive feedback on My Builder.

The latter one was a pleasant chap who came across as very professional and informative. He's also the only one who gave me a quote. He's offering a 30 year guarantee for his work. He quoted £2500 for the following:

[FONT=&quot]All exterior walls to be drilled and injected along motorline [/FONT]
[FONT=&quot]air bricks replaced or repaired [/FONT]
[FONT=&quot]cavities checked for debris horizontal and vertical drilling.[/FONT]
[FONT=&quot]Slabs to be sealed at front of the property where water ingress is evident (this is a sizeable 5ft by 5ft slab which is the main source of water into my cellar)
[/FONT]
[FONT=&quot]interior of the property walls to be drilled and injected in places pointed out on survey in both lounge and dining room (two bay windows, a 4ft section in one room and then another 15ft section in another)
[/FONT]
[FONT=&quot]attention to hallway wood with wood worm treatment
[/FONT]
[FONT=&quot]Wood treatment needed in cellar and room off cellar wall for dry rot and fungus [/FONT]
[FONT=&quot]cellar to be DPC in places mentioned (this is along one wall, about 8ft and then another small room directly beneath the slab mentioned above). [/FONT]
[FONT=&quot]Kitchen floor drilled and treated for !!!8216;rising salt!!!8217; by injecting membrane under stone tiles (they're the original from when the house was first built).
[/FONT]
[FONT=&quot]Treatment for fungus in cellar and kitchen[/FONT]
[FONT=&quot]Damp proofing membrane in wall outside kitchen (roughly 4ft where rendering has fallen away and bricks have begun to rot - he did say this would only be a stop-gap until bricks etc repaired)[/FONT]
[FONT=&quot]Adjust pipe outside so leading water away from base of house
[/FONT]

He offered to do the work associated with the cellar, which is my main concern, for £1400. He explained almost every bit of the work including his methods but he didn't mention any re-attachment of skirting boards or radiators or re-plastering etc. He also invited me to double check any concerns with the internet and has been fairly good at communication. I identified the damp and his 'damp meter/detector' confirmed it. He said that he didn't need to remove plaster etc as it would up the cost and he could deal with the issue by drilling instead. He said that the fungus and wood worm could be poisoned without excessive spraying. He took the time to look around the full base of the house, inspecting walls etc where he could.

My house is a detached. It was built in the 1900's but had some modernisation work done in the early 90's. There's clearly sign of fungus and rot in the cellar ceiling (ceiling is the floor above) but the wood is still hard and the worst 'infection' seems to be purely masonry based at the moment and in the old wooden steps which have been removed.

Basically i'm just looking for some advice. Does this quote seem fair and reasonable? Would you take the plunge and get it done?

Thanks in advance!

FreeBear · 2 August 2018 at 12:39AM

Semper wrote: »

I identified the damp and his 'damp meter/detector' confirmed it.

My house is a detached. It was built in the 1900's but had some modernisation work done in the early 90's.

Would you take the plunge and get it done?

This "damp meter" - Was it one of those gadgets with sharp prongs that you poke in to the wall ?

If so, be advised that they are only suitable for use on wood, not plaster, walls, bricks, or slabs. Things like salt content, paint (particularly old lead paint), and even the type of plaster all affect the readings given and can not be trusted.

Chances are that the existing DPC is fine and you have damp problems caused by elevated ground levels, leaking gutters, or roof defects. On a turn of the century property, it is unlikely that you have a cavity (but there will be one on the extension), so drilling holes in the wall is not going to serve any purpose.

Injecting a "membrane" under the tiles in the kitchen is possibly the worst thing to do - It will push moisture in to the walls causing further (expensive) problems in the future.

The name "Peter Cox" sounded familiar.... https://www.heritage-house.org/damp-and-condensation/all-about-the-pca/peter-cox-damp-proofing.html

Have a read of the Heritage House site, pop over to the Period Property forum, and then get an impartial survey & report done.

Semper · 2 August 2018 at 11:02AM

Hi and thanks for the information, it is helpful to have a second opinion. I'll post the same question on the forum.

He did use a two pronged yellow device with a scale, the second expert used the same device in the same manner (both from separate companies). I am aware there's damp as in the winter there are clear wet marks on the walls. Two sections are near pipes, two others are not but there is definitely a minute slant away from the house, so if anything the house is probably raised?

I'll give Peter Cox a cancel and I had some budget concerns anyway so leaving the floor and just continuing to polish it will be fine for now.

I'm struggling to find an impartial surveyor in my area for a reasonable cost (I don't have the hundreds to get a survey and get the work done).

Doozergirl · 2 August 2018 at 12:06PM

I don't have a great deal of time at this very minute, but if the slab in the main source of ingress, the the slab needs to be removed, or at least cut right back away from the house! What the hell is sealing going to do? It's like putting a sticky plaster on a broken leg.

The quote is ridiculous. They're just finding stuff to do that they like doing.

What is the situation with air bricks? How many, are they clear, at what level to the ground etc?

If you can post pictures of affected areas inside, pictures of the outside of your house etc then we can offer plenty of advice. All your pictures need some sort of context to them, though, so we can see how each picture corresponds to the next and understand where the problems are located.

Don't act desperate with people. If someone isn't available for a week, it's pretty normal. People sitting around waiting for your call is not!

FreeBear · 2 August 2018 at 12:42PM

Semper wrote: »

I am aware there's damp as in the winter there are clear wet marks on the walls. Two sections are near pipes,

If these are cold water or waste pipes, then damp around them in winter is not unexpected. The pipes will generate a cold spot on the wall, and moisture in the air will condense in the area - No amount of fancy waterproof render or plaster is going to cure that. Pipe insulation will go some way to minimising the problem and will only cost a pound or two (and it is something that you can do yourself).

Semper · 2 August 2018 at 1:14PM

@Doozergirl, I will acquire some pictures after work this evening. Thank you for the insight.

@FreeBear. Apologies, I may have mis-represented that specific situation. The main areas where I have found the water marks in the winter are below a gutter (perhaps 18ft or so) on one side.

On the other the water is rising up from where a gutter pipe ends, letting water out (it runs onto the ground with no pathway made so it can and does end up at the base of the wall that has the damp). I have a pipe to direct the water away in this second area.

My biggest concern is the fungus and rot in the cellar. I simply don't have the budget to replace a floor and get a ton of DCP work done and as the rot hasn't progressed I am hoping to get it tackled before it does and I have to replace the floor. Again, thank you both. I'll grab some pictures and post them with context tonight. I really am grateful as i'm completely out of my league and too swamped with a myriad of responsibilities to get to grips with this without the kind of insight you're providing.

FreeBear · 2 August 2018 at 2:40PM

Semper wrote: »

The main areas where I have found the water marks in the winter are below a gutter (perhaps 18ft or so) on one side.

On the other the water is rising up from where a gutter pipe ends, letting water out (it runs onto the ground with no pathway made so it can and does end up at the base of the wall that has the damp). I have a pipe to direct the water away in this second area.

Sounds like the downpipe is blocked, as is the underground drain & soakaway. There may well be a leak on the gutter as well - If none of these are fixed, any remedial action taken inside the house will be wasted.

Get someone in to clean the guttering & downpipes (do all of it to be on the safe side). Locate the soakaway, and try to identify if it is full of debris. Use drain rods to clear out the pipe leading to the soakaway. Worst case, you will need to dig out and replace the soakaway and drain pipes.

Once drainage is sorted out, give the house a chance to dry out and then look to see where any remaining damp is located - There is a good chance that it is the result of relatively small problems outside that can be fixed without spending huge amounts of money.

Semper · 3 August 2018 at 10:47AM

Hi,

I tried to post some images and links but it will not allow me as i'm too new a user.

FreeBear · 3 August 2018 at 11:49AM

Semper wrote: »

I tried to post some images and links but it will not allow me as i'm too new a user.

From a PM sent to me, the images in question.

Semper wrote:

Some images.

This is Wall A (starting from the left, under the black gutter at the top). The internal signs of damp appear from about 2/3'ds the way down this wall, to Corner A and into bay window A, round to corner A2 which resides next to the front door.

This is Wall A internally, with an example of a power socket I am avoiding use of (socket A), this is in the internal of corner A.

There are no signs of damp there at the moment but when it rains heavily I can clearly see dark, damp patches appear a long the dado rail and coming up from the ground near corner A and half way down near plug socket A2.

There is no sign of damp in the cellar beneath Wall A, in fact it appears to be solid ground; however, Wall A also connects to the kitchen floor.

(I didn't get the best photo)

This is external, corner B.

As you can see, corner B has a pipe ending right at it's base and it's not directed away, with spaces in the stones nearby, seemingly allowing water ingress. I have a piece of pipe to put at the bottom to direct the water away, I have not installed it yet as more than one proofer has said it wouldn't do nothing, but it wouldn't fix the issue.
This is corner B internally.

Aside from the wall feeling damp after rain, there is no sign of damp at ground level internally. My decorator discovered the damp feeling wall and decorated around it for me for now.

This is internal of corner B from the cellar below. The 'ceiling/floor' in this corner has fallen in (a space about 2ft square). I fudged the photos but will get more.

This is the air brick from the cellar. It is completely blocked.

There is a mossy fungus growing beside it.

This is the aforementioned stone slab.

In the fore of the picture, to the left of the door is corner A2 to give you some bearing. As you can see, from the top, the slab appears to be cracked on the far side of it.
This is the slab from the cellar...

This is the ceiling of the tight hallway leading to the slab..

As you can see, lots of water condensation. In winter, if it's raining, I can go towards the slab and clearly see drops on it, leading me to believe the slab is leaking in.

These are some general shots of the cellar.

FreeBear · 3 August 2018 at 12:07PM

If you look to the right of the drain pipe, there appears to be a mortar joint at ground level that is thicker than the others - I suspect this is the DPC. The pavers under the down pipe should be removed and then you need to dig down between 100mm & 150mm. The air brick(s) certainly needs unblocking as this provides ventilation in the cellar.

The slab you referred to in your original post - No amount of sealing will stop condensation forming on the underside. In the winter, it is going to be very cold and water will naturally condense on it. There may be some water penetrating around the edges, but it would have a tendency to run down the walls and wouldn't form droplets in the middle. Putting some insulation up along with a vapour control membrane would go a long way to reducing condensation on the underside of the slab.

I would recommend getting the air bricks unblocked, the down pipe, drainage, and guttering sorted as a priority, then look at resolving the root causes of damp. No point in wasting money on expensive "cures" without fixing the sources.

Semper · 3 August 2018 at 4:28PM

Thank you for posting and giving me some insight. I've got an independent surveyor coming around in the middle of next week as they've agreed to give me a verbal report for £90, which isn't a desired cost but it's something I can accommodate and they said I can use a voice recorder.

In regards to the first part, digging 100-150mm down, when i've dug, should I be putting in a new DPC? There is a black DPC sheet (in the last pipe picture, in the top right corner you can just spy it between the bricks).

Damp Proofing

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