DIY - Damp proof course using cream?

trickys77

Thanks! Ok so I've been busy reading alot on the internet based on the advice here and I'm starting to understand that this is most likely not rising damp. I just read that for my age of house only 4% of houses will actually have rising damp and yet 90% will be told they need a new damp proof course.

The issue is that I think I need a expert who can tell me the true cause of the damp and the 3 firms I have had around already have all told me it was rising damp.

Any advice of how to find a firm that will do some propor checks rather than just using a moisture meter?

Thanks again for everyones help, I think I have just been saved spending £2000 for something that would not fix my problem.

David_Aldred

Hi Trickys77,
Please have a look on the Property Care Association website
www.property-care.org and on there select find a member and select either Freelance Surveyor or Consultant both of which give truly indpendent specialist advice and you should find one in you area. The other members on their are contractors. Either that or do a Google search under independent damp surveyor and select a surveyor who covers your area and give them a ring to discuss things.

Hope this helps,

Kindst regards, David Aldred Independent damp and timber surveyor

David_Aldred

There is a very big reliance by the contractors who sell chemical dpc's on the re-plastering which will for a while hold back a multitude of causes for dampness. I have seen them drill holes and not inject at all but simply re-plaster and guess what - hey presto a relatively dry surface for you to decorate - so much for the justification for chemical dpc.

The fun starts when sooner or later the true cause of the dampness other than the guess at dpc failure reasserts itself and the plaster / finishes start to degrade once more.

You then recall the dpc contractor who turns round and says - sorry nothing to do with the dpc it's "xyz" and of course they are right because it was nothing to do with rising damp in the first place.

Typically the guess at rising damp is done by surveyors and contractors with electrical damp meters but the re-inpection when you start complaining is done by taking a drilling and doing a carbide meter test which is something completely different.

You may wish to query at this stage if the high electrical damp meter reading was good enough for them to say it was rising damp why is not good enough now at the re-inspection when there are still such high electrical damp readings....mmmm.

Just to put the icing on the cake you sell the house and along comes another dpc contractor and gets a high reading again with an electrical dmp meter and says guess what the previous chemical dpc and the one the house was built with are both no good and so the whole cycle repeats itself until hopefully and god willing somebody with a bit of common sense looks at that property and figures out what has changed since it was first built and uses simple traditional good construction to resolve the true causes of the problem.

Kindest regards,

David Aldred Independent damp and timber surveyor

trickys77

David,

I just phoned a few more companies one of which was peter cox. I asked them how they test for damp and they said using a damp meter. He was already saying over the phone that it sounds like rising damp before even seeing it. I then asked about the accuracy of damp meters and if a carbide test would be better and he said that they can do that for £75 but sometimes the moisture meter is more accurate!

I guess I would be better off finding an independant rather than paying £75 to a company that wants to sell me something. Shame you don't live near me! I live in warwickshire and cannot seem to find independants anywhere near me.

David_Aldred

Hi Trickys - Although I travel all over the UK in my profession in no way do I want to be seen to be selling myself to folk on here and the comments made are simply from my experience and knowledge of an industry which when I see damp proof courses and other treatments going in through misdiagnosis I simply find to be morally wrong.

A carbide meter used on site gives a total moisture reading comprising moisture absorbed from the air and moisture from any other source be that penetrating damp or rising damp, it does not distinguish between the components within it. The carbide meter reading can be very high indeed simply through the wall absorbing moisture from the air alone without any rising damp or penetrating damp being present in the sample and so it may be seen even this does not confirm rising damp at all. I have seen contractors inject a wall time and again from a high carbide meter reading when the cause of the high reading was totally moisture being absorbed from the air.

Kindest regards, David Aldred Independent damp and timber surveyor

dampdaveski

Hi tricky
It sounds like you have much more than a bit of rising damp, i agree with David, as always he gives good advice shrouded in an avalanche of words
Only point to note is that the manufacturers reps are more desperate to sell product than preservation companies (allegedly ;o) )
Also a point to note, by your own admission you don't know a great deal about preservation work, this forum is NOT the ultimate fountain of knowledge. As you've had a few idiots potentially trying to sell something that may not be needed round I suggest putting your hand in your pocket and getting an independant in, so that at least you have peace of mind etc.

DD

mikey72

I had rising damp.
Late 1800's terraced property, damp 1m up, internal and external walls.
No dpc, and clay tiles over soil for the floor. Skirting board was rotten as well. The property had a cement render outside, floor to bottom of the windows.
I took off the bottom foot or so of this, removed the plaster inside, had a company inject a cream internally, and got an insurance backed guarantee, and left a lot of the wall unplastered but either drylined, or tongue and groove cladding over it. (Some I had to cement render, but I figured this would stop it drying out properly) It did dry out slowly, so it worked for me.
Cost was about £400 from memory, and I have all the right paperwork as well for that price. I also had an ashphelt floor poured to finish it.

trickys77

This damp stuff is very confusing so thanks for all the tips!

So I’ve been reading allot of articles on the internet about common causes and have re-assessed my house with fresh eyes:

Upstairs –

Black mold spores present in various places (including internal walls) and wall paper lifting at high levels close to ceiling and low (close to the floor boards) around of the whole upper floor. Middle of the walls seem unaffected. I noted that upon closing or opening of doors upstairs, all the others move. Damp meter indicates no current damp in walls. Damp was however detected on the chimney stacks in each room. No ventilation upstairs resulting in high condensation levels further compounded by damp walls downstairs. Previously blocked up fires in each room have not been vented in any way creating a still air gap between the 2 surfaces. Leaking pipes can be ruled out since the water has been turned off at the property for over 1 year. This will be double checked upon installation of the new heating system. Bowing and failed plaster (at the same level as the guttering) in the upstairs external facing walls, expected to be failed guttering leaking water back onto house. (I believe that this must be fixed as even after lots of heavy rain the damp meter reading is low.) Leaking flashing on the roof joining the ‘party’ roof, which is causing water to run along wooden frontage and into the walls in the upper front room causing plaster to fail and mould to grow.

Expected remedial work:

Check guttering and roof to make sure that they are water tight with no leaks against the house. Repaint and repair any external render to prevent future penetrating damp. Remove failed plaster, skim with a concrete render mixed with silicon on external walls, allow to dry then skim with salt resistant plaster. Add air vents into each blocked up chimney and/or cap off the top. Add extractor fan into bathroom. Fix the roof flashing. Replace old iron guttering and wooden fascias with vented PVC versions (noted on neighbours properties).

Downstairs –

Wallpaper pulling off at the bottom of the walls and plaster has failed around the front and the internal structural wall. Moisture meter readings taken from various locations indicate that water has risen to around 1 meter, above which the reading becomes normal. The readings seem to be higher in the front wall and structure internal wall. The rear wall seems less affected. A retro fit vent was noted in the rear of the property. Floor boards are discoloured in areas around the walls at the front of the property and structural internal wall indicating they are also damp. Carpets that were lifted had rotten under lays. Cardboard boxes placed on the floor boards for 2 weeks are also showing signs of water damage. Concrete drive appears to slope towards the house and a small concrete ‘step’ is attached to where the drive meets the house (front of house only). In places this has cracked and broken away displaying a small trench underneath around 4cm in width and filled with stones. The house has a suspended wooden floor with several large airbricks in the cavity below the floor at the front, rear and side of the property. The air bricks appear to be blocked and are at the same level as the concrete ground outside. The internal party wall seems to be unaffected however high damp readings were noted on both chimney stacks (on the party wall). The front of the property is painted up to the level of the windows, after which it is pebble dashed rendered and painted. No obvious cracks or defects can be seen in the external wall. The paint around the base of the house is dry and flaking in various points around the side and rear of the property. At the rear of the property, around the drains a few bricks seems to be flaking on their outer layer. I could not see a damp proof course by either external or internal (under floor) inspection – although limited to torch light so will re-inspect tomorrow.

Expected remedial work:

Repaint and repair any external render to prevent future penetrating damp. Remove failed plaster, skim with a concrete render mixed with silicon on external walls, allow to dry then skim with salt resistant plaster. Add air vents into each blocked up chimney and/or cap off the top. Add extractor fan into kitchen. Clear the blocked vents. Remove the concrete step that is resting against the house. Inject a cream based damp proof course 6 inches above the ground and below the suspended floor or locate the DPC and if needed lower the ground level to 6 inches below this level. Treat timbers in contact with the walls with water proof sealant.



Anything I missed???

David_Aldred

Hi Trickys,
In answer to your question anything I missed? - Yes, a lot will respond either on here or via private e-mail but have to shoot off to Yorkshire to do a survey so am just rushing out the door.

Kindest regards, David Aldred Independent damp and timber surveyor

myhooose

I installed the safe guard dpc cream myself. We don't intend selling the house any time soon so was not too bothered about a guarantee. The only problem I encountered was when drilling into the mortar on internal single skin walls. The mortar would break away on the other side of the wall making a hole right through the wall.

I installed a cavity membrane on the party wall as this was the most badly affected. I don't think any amount of dpc cream would have helped on this wall. The membrane allows the wall to breathe, like the tongue and groove paneling on the old farm houses.

To be honest (now living in the house) I think only a few patches and the party wall were suffering from rising damp. The rest of the damp was cured by heating and by installing good extractor fans in the kitchen and bathroom.

In a different post David Aldred posted a long explanation as to why damp occurs when changed are made to a house. This almost exatly mirrors what has happened in my house. I'm slowing putting it all right. Next job is to sort out the drive and drainage outside the house