DIY Damp Proof Injection

[Doug71]

I had a firm out (Timberwise) to ***** damp walls in my mothers house. They said it has rising damp problems which we knew and they have quoted almost £2k to inject it all and plaster 1 small wall.

I have seen injection kits online like the link below which would do it all for £165, the plastering is not a problem.

https://www.permagard.co.uk/dpc-damp-proofing-cream-kit

Anyone tried the DIY approach or have experience of similar kits, looking to save money where we can.

Thanks in advance, Doug

 

[MikeG.]

Don't do it. Injected damp courses don't work, and should be banned. They are willful vandalism. I bet they also want to replaster a metre high around the inside of the room with some rock-hard plaster. Get a surveyor who knows something about old buildings.

 

[novocaine]

What Mike said. A complete con. Figure out where the waters coming from. More likely to be a busted down spout or a blocked vent than damp. Not to mention filled cavities, poorly fitted windows and outside ground heifhts being raised.

 

[owen]

Take the plaster off 1.5m high and tank it with sovereign chemicals k11 slurry, use renderlite over the top and that will sort it. Damp proof injection does work but it doesn't last, we did some properties 10-15 years ago and we are redoing them now but using the k11 instead.

 

[Blackswanwood]

This is worth a quick read.

https://www.heritage-house.org/damp-and ... dings.html

 

[MikeG.]

Take the plaster off 1.5m high and tank it with sovereign chemicals k11 slurry, use renderlite over the top and that will sort it. Damp proof injection does work but it doesn't last, we did some properties 10-15 years ago and we are redoing them now but using the k11 instead.

Respectfully, this is not the answer for an old building, at all. I suggest that the OP reads the advice from SPAB.

 

[Woody2Shoes]

I had a firm out (Timberwise) to ***** damp walls in my mothers house. They said it has rising damp problems which we knew and they have quoted almost £2k to inject it all and plaster 1 small wall.

I have seen injection kits online like the link below which would do it all for £165, the plastering is not a problem.

https://www.permagard.co.uk/dpc-damp-proofing-cream-kit

Anyone tried the DIY approach or have experience of similar kits, looking to save money where we can.

Thanks in advance, Doug

I am prepared to bet you a significant sum of money that this is not the solution to the problem (whether diy or biy).

 

[thetyreman]

that chemical injection kit will have some very nasty chemicals in it, they are an absolute con and none of it based on real science, drilling holes into a wall is not going to stop damp, use common sense, look for the real cause of the damp, it's worth watching some peter ward videos.

 

[Sachakins]

Hi,
Without knowing the wall type and construction materials this is impossible to answer.

Damp proofing with DIY injection is hit and miss, done it myself twice on two properties, waste of money IMHO. Had done professionally 2 years later on one now ok.

The other turned out to be penetrating damp, caused by perished mortar in several places., Raked it out and repointed with appropriate mortar, suitable for the type of wall. Hacked off plaster and let it dry for 6 months, replaced with appropriate plaster rendering, as solid wall construction, this needs to breath, sealing it with tanked style finish would have left wall no way to breath, so moisture build up would occur.

 

[owen]

Take the plaster off 1.5m high and tank it with sovereign chemicals k11 slurry, use renderlite over the top and that will sort it. Damp proof injection does work but it doesn't last, we did some properties 10-15 years ago and we are redoing them now but using the k11 instead.

Respectfully, this is not the answer for an old building, at all. I suggest that the OP reads the advice from SPAB.

It works just as well on old buildings as new, what's the problem with it?

 

[owen]

What Mike said. A complete con. Figure out where the waters coming from. More likely to be a busted down spout or a blocked vent than damp. Not to mention filled cavities, poorly fitted windows and outside ground heifhts being raised.

Not exactly a complete con, as long as the damp is rising damp not penetrating damp then it works, it just doesn't last forever.

 

[MikeG.]

Take the plaster off 1.5m high and tank it with sovereign chemicals k11 slurry, use renderlite over the top and that will sort it. Damp proof injection does work but it doesn't last, we did some properties 10-15 years ago and we are redoing them now but using the k11 instead.

Respectfully, this is not the answer for an old building, at all. I suggest that the OP reads the advice from SPAB.

It works just as well on old buildings as new, what's the problem with it?

It fundamentally misunderstands how old buildings work. It adds non-porous, non flexible materials to buildings which depend on porous and flexible materials in all sorts of ways. It moves damp problems into other parts of the building. It masks the real issue, which is almost always to do with lack of ventilation, concentrated sources of damp, raised ground levels, inappropriate repairs or finishes, or service penetrations.

There are two fundamentally different approaches to keeping a building dry: the modern one with impermeable materials used strategically (DPM, DPC, etc), and the old one which uses lime and porous materials (including bricks as well as lime based renders and plasters) which absorb moisture when conditions are damp and release it when conditions dry, relying on good ventilation. They both work absolutely beautifully, but they are incompatible. The issues always arise when there is an attempt at a hybrid of the two.......modern interventions in an old house. Most timber frame houses were absolutely perfect for 400 years, until they were renovated in the 70's and rendered with sand/ cement, and had a concrete floor with DPM inserted. Within a couple of decades, most of the sole plates in those buildings had rotted away. Same with lime-mortared brick buildings which were repointed with sand cement mortar, or rendered with cement based render. Unrenovated buildings, without DPMs and DPCs, are still absolutely fine for another few centuries.

Thoughtless and inappropriate modern interventions, such as injected DPCs and internal tanking, are a disaster for old buildings. If I had my way they would be banned for any house built before about 1950.

 

[sammy.se]

As someone who has been dealing with damp for the last twelve months (and not finished yet!) I would listen to all the advice here, which is correct and which I have taken on board in order to remediate the issues I have.

The DPCs in the older buildings, e.g. slate, rarely fail, so injecting a new DPC is seldom the answer.

I would exhaust all other reasons why damp is being created, not least of which is the wrong materials being used, before considering any injections. I've hacked off half the external render on my walls, for example.

 

[Doug71]

I appreciate all the advice thank you.

The main problem is a 9" internal solid brick wall, before an extension was built on maybe 35 years ago this was an external wall. The wall is really wet, the stair string against it has rotted and so have the skirting boards, I presume it has never had any kind of damp course in it.

The wall is only about 3m long, I have seen people remove a couple of bricks at a time and insert some modern dpc, anyone tried this?

Thinking about it the top of this wall is still external and has a flat roof coming off it, maybe this could be the problem and the damp is coming down as well as up :roll:

More investigation needed.

 

[Woody2Shoes]

..........
Thinking about it the top of this wall is still external and has a flat roof coming off it, maybe this could be the problem and the damp is coming down as well as up :roll:
.......
More investigation needed.

Bingo! It is enormously more likely that the damp is coming down - rather than rising up. I would look very carefully at the flashings at the junction between the flat roof and the external/internal wall, at the state of the flat roof generally (is there scope for puddles to form?) as well as the weatherproofing of the external wall above the flashing (and how water gets safely off the roof above that). Photos might be useful, cheers, W2S

 

[novocaine]

How are detecting that the wall is wet? Better yet,how have the damp people tested it? Just wondering because i bet its not with a carbide tester.
I thibk you may have found your problem with only a little bit of thought. Yey.

 

[Woody2Shoes]

...The wall is really wet, the stair string against it has rotted and so have the skirting boards, I presume it has never had any kind of damp course in it.....

The thing is, in a building of this vintage, it's highly unlikely that any wall - internal or external - would be built without a dpc. And, as has already been mentioned, only slightly less unlikely that any dpc is not working substantially as well as it did on day one.

 

[owen]

It works just as well on old buildings as new, what's the problem with it?[/quote]

It fundamentally misunderstands how old buildings work. It adds non-porous, non flexible materials to buildings which depend on porous and flexible materials in all sorts of ways. It moves damp problems into other parts of the building. It masks the real issue, which is almost always to do with lack of ventilation, concentrated sources of damp, raised ground levels, inappropriate repairs or finishes, or service penetrations.

There are two fundamentally different approaches to keeping a building dry: the modern one with impermeable materials used strategically (DPM, DPC, etc), and the old one which uses lime and porous materials (including bricks as well as lime based renders and plasters) which absorb moisture when conditions are damp and release it when conditions dry, relying on good ventilation. They both work absolutely beautifully, but they are incompatible. The issues always arise when there is an attempt at a hybrid of the two.......modern interventions in an old house. Most timber frame houses were absolutely perfect for 400 years, until they were renovated in the 70's and rendered with sand/ cement, and had a concrete floor with DPM inserted. Within a couple of decades, most of the sole plates in those buildings had rotted away. Same with lime-mortared brick buildings which were repointed with sand cement mortar, or rendered with cement based render. Unrenovated buildings, without DPMs and DPCs, are still absolutely fine for another few centuries.

Thoughtless and inappropriate modern interventions, such as injected DPCs and internal tanking, are a disaster for old buildings. If I had my way they would be banned for any house built before about 1950.[/quote]

That all makes sense. I wasn't thinking of timber framed buildings, we dont get many of them around here, the peak district. I was more thinking of terraced brick built houses with solid double skin brick walls. What about older places with solid stone walls? Is tanking acceptable then?
What damage can it cause apart from the timber rotting?

 

[owen]

...The wall is really wet, the stair string against it has rotted and so have the skirting boards, I presume it has never had any kind of damp course in it.....

The thing is, in a building of this vintage, it's highly unlikely that any wall - internal or external - would be built without a dpc. And, as has already been mentioned, only slightly less unlikely that any dpc is not working substantially as well as it did on day one.

How old is the house? I don't think it's been mentioned?

 

[MikeG.]

........ What about older places with solid stone walls? Is tanking acceptable then? ......

Again, the lime mortar in the walls, and lime plaster internally, is what moderates the moisture content of these buildings. The key thing is to get all the fundamentals right (ground levels, service penetrations, no sources of concentrated damp, ventilation, etc), and to keep the materials consistent (avoiding gypsum-based plasters, for instance). I currently have a project on the go in Butterton, in your neck of the woods, having done 4 or 5 projects in the Peak District previously, all old stone buildings. There are no damp issues in any of the finished projects, and not a single DPC or DPM anywhere. The current project has a stream running under the flags of the kitchen floor. A torrent really, that you can hear even when the kettle is boiling. This house will be dry when we've finished, and there'll be no plastic or gypsum anywhere in the building. Tanking is never the answer, and lime plaster always is.