Rising damp?

eastofeden

Would appreciate any thoughts on this. I have just had my kitchen completely re done and am generally very pleased with it. I have noticed a bit of damp/flaking paint and plaster just above skirting level on one inside wall. Outside the wall was rendered and the bricks covered and then painted white. I think this will be the issue, from surfing around the internet. My Polish builder is returning tomorrow and has talked about hiring a machine to inject a treatment.

Does this sound right, and should he foot the bill? I am not very clear about damp proof courses etc, and being a single lady, do not have much of a clue in this area!

Please advise, I would be so grateful!

Steve_xx

You would be better to get three quotes from specialist firms. See what each of them say as they may not give the same opinion.

If the outside wall is rendered then you might check it carefully to see if you can see any cracks in it where rainwater might be ingressing. You should also check that the rendering has not bridged the damp proof course, assuming that there is one? If the rendering touches the ground then it is likely that the damp course has been bridged and if it has then you will need to hack of the render to a point above where the damp course is.

If the polish guy has rendered the outside wall then it might be that he has bridged the damp proof course as mentioned above. If this is the case then he ought to foot the bill to put it right.

Damp proof courses are generally built into a property from new and new properties will have a layer of polythene (damp proof membrane) running along the course of bricks just above ground level. This stops damp being drawn up through the porous bricks and into your home. Sometimes houses dont have them and become damp. The easiest way to remedy the problem is to drill holes about halfway through the inside and outside walls, at a point where the damp proof course would normally be. Then into the holes a silicone watery substance is injected/pumped and it is supposed to seep into the bricks and reduce their porosity, thus stopping damp being drawn up from the ground and into your house.

eastofeden

Thanks for your great reply. I get very paranoid on here as others seem to get so many responses! Greatly appreciated! It is rendered to the ground, so I think you are right. I know I should know, but no idea about damp proof course. I will talk to him today. One thing I have going for me is that sevearl neighbours want to use him, so this could be a payment lever!!

lagi

I have had similar problem with some advice somebody gave me about my garage. I had it rendered and my friend said to have it rendered to the ground. Although i am glad its not connected to the house the bottom layer of the garage rendering always looks damp as its pulling the moisture up from the ground. It sounds similar to what has been done to yours. I have since found out and seen on other properties you would have a stop bead put on where damp proof is (a piece of metal they render too), they render to this. So i wouldn't worry about your damp proof course just yet as it may be fine. Get some different quotes and i am sure they will just chip off the render that is below dpc and make good the rest. Looks like builder made mistake and was concentrating on getting straight finish outside. Bit worrying that he thinks its dpc now though.

Steve_xx

eastofeden wrote: »

Thanks for your great reply. I get very paranoid on here as others seem to get so many responses! Greatly appreciated! It is rendered to the ground, so I think you are right. I know I should know, but no idea about damp proof course. I will talk to him today. One thing I have going for me is that sevearl neighbours want to use him, so this could be a payment lever!!

It's ok, you can't know about everything. It's good that people on here can offer eachother opinion/advice.

If it is rendered to the ground, and it wasn't before, the chances are that this will be the cause of your problem. If the polish guy has done the rendering, then really he ought to put it right. It's shouldn't be a huge problem for him to hack some of it off so that it's just above the damp course. Injecting the walls with damp proofing liquid will not cure the problem if the rendering remains in touch with the earth.

jimexbox

eastofeden wrote: »

Thanks for your great reply. I get very paranoid on here as others seem to get so many responses! Greatly appreciated! It is rendered to the ground, so I think you are right. I know I should know, but no idea about damp proof course. I will talk to him today. One thing I have going for me is that sevearl neighbours want to use him, so this could be a payment lever!!

If it was your Polish builder that did the rendering I would be careful in reccommending him to your neighbours. I mean render should never cover your DPC, like Steve said it acts as a bridge causing water ingress.

Ive had one or two people I know in state of panic re. damp. They were prepared to spend thousands on bringing damp proof firms when the cause is usually staring them right in the face.

ariba10

I am not sure but In think this is the only country that uses a damp course.

I know of someone on the Portuguese Algarve that built their own home and wanted a damp course.

The local authorities made them bridge the area above and below the damp course with metal straps.

Steve_xx

ariba10 wrote: »

The local authorities made them bridge the area above and below the damp course with metal straps.

I'm not exactly certain as to what you mean?

There is a form of damp proof coursing referred to as osmosis. This type of damp proof course involves putting a metal strip where the damp course would normally be installed. The metal strip is then connected, via a transformer, to the electricity supply. This stops the damp rising.

Here is some more information about this type of damp proofing. I've not heard of anyone who actually has this system in place.

http://www.ultimatehandyman.co.uk/ELECTRICAL_DAMP_PROOF_COURSE.htm

ariba10

They did not like the idea of a layer of material laid across the block work.

They said they thought it possible that the material laid on top of it would be unstable.

Steve_xx

ariba10 wrote: »

They did not like the idea of a layer of material laid across the block work.

They said they thought it possible that the material laid on top of it would be unstable.

Oh yes I see what you mean now. I guess that it is possible for it to be a bit unstable when you consider that the course is a layer of plastic that sits on mortar and has mortar above it. Youcould imagine the possibility of the building sliding off of the damp proof course! I'm not sure whether the actual plastic they use has some qualities that make it adhesive to mortar.

Sometimes granite/slate is used for a damp proof course and this is probably the best method because it will readily adhere to mortar and probably wont brak down as quickly as a plastic course.