!!!!Damp Proof Course!!!!

[martin123]

Hi, This is my second posting regarding a DPC.The first one was about a guarantee which turned out to be worthless.

My semi detached house was built in 1887 and already has a DPC injected, the skirting in the downstairs bathroom was rotten and when i took it off the plaster was covering the DPC holes, although it was a different plaster to what the walls are skimmed with.The plaster was moist and very crumbly, Yet the plaster above the holes is solid apart from a few 1 inch blow holes.

I have had 4 estimates from different companies and all of them give me different answers including,

1)Having a new DPC injected on all external walls apart from the front.

2)New DPC injected on some external walls excluding kitchen but including front

3)All external and internal walls and either side of chimney breast which is joining next door and some interior walls.

4)And the latest one this morning said all 3 chimney breasts needed tanking and just the rear of the property including the bathroom needed a new DPC.

I asked the bloke this morning if the DPC had failed and he replied he doesn't know you need a different meter which needs to be injected into the wall rather than his hand held damp meter.

I need a straight answer before i have my walls skimmed and i redecorate, besides im running out of coffee to give them.Is there a meter i can buy myself and is there anyone in the trade that can give me advice. I can send photos.

Cheers

 

[masona]

I need a straight answer before............

Sorry to tell this,I have got no time for these people as they will never cure damp problems completely and you might not even have DPC if it built in the early years! See this to help you to make up your mind.I don't want you wasting your money.If you feel you want to go ahead then you can hire the dpc injector with the chemical and diy to save money.

 

[martin123]

Masona, It already has a DPC injected as i can see the plugged holes outside and holes behind the skirting board.I asked one surveyor when he thought it had been done and he told me he remembered coming round 3 years ago to give a quote............kinda funny the crap they come out with eh?

 

[masona]

kinda funny the crap they come out with eh?

At least you've got a better understanding now.

 

[martin123]

Ive had a thought.....Screwfix sell a liquid damp proof membrane, whats wrong with hacking off the plaster on all external walls to 1200mm to get rid of any salts.Then painting the brickwork with the membrane up to 1200mm then rendering as normal and have the walls skimmed.Im refurbing every room and was going to have them skimmed anyway.

Any problems with this??????

 

[masona]

Providing the walls is dry before applying the treatment otherwise it will trap the moisture in the walls.The walls got to be dry before you do anything,this why the dpc injection company don't always works.You really got to find out what causing the damp in the first place.

 

[martin123]

I was hoping you was going to say, yeah thats fine, a great idea, go for it!!!

Next thought is phoning the rics surveyor who i used before we moved in,he sounded like a good bloke, and asking if i pay for his time will he have a look while the walls are stripped

 

[masona]

I was hoping you was going to say, yeah thats fine, a great idea, go for it!!!

Nothing is ever straight forward

And a good idea for the surveyor inspection when the walls are stripped which should help further into what's happening.

 

[miah]

Hi All,

I've noticed in the weblink put by Mosonan a point, painting outside masonry.

We were thinking of painting our external wall's, is this going to cause any problem?

Avoid sealing the walls outside with masonry paints which stop moisture reaching the wall but also trap moisture in the wall. If the paint flakes, moisture can enter the wall but not escape. This can cause spalling of the brickwork as well as damp problems.

 

[masona]

We were thinking of painting our external wall's, is this going to cause any problem?

Not if the damp is coming from the outside and into your walls which will protect it but if the damp is internal the outside paint will flakes.The biggest problem I'm finding is people are painting the wall before finding out what causing the damp in the first place.

 

[miah]

Mosonan,

I believe there's no sign of dampness in our internal or externally walls apart from rising damp which has damp course injected.

However, my question is painting the wall using masonry paint for brick will this be a problem?

 

[masona]

However, my question is painting the wall using masonry paint for brick will this be a problem?

Shouldn't be a problem but it the only way to find out sometimes.If the dpc was injected by a company there should be a guarantee with it.

 

[DavidH]

We are renovating a old house which backs onto a small road. The road level comes half way up the wall, all the way along one side of the property.

We had the wall tanked, which involved the painting/spreading of a strange grey goo over the damp walls. This was supposed to dry to form a barrier to the moisture.

We found small patches still remained damp (not bad but noticeable) and had to get the dampproofer back 3 times to give it extra coats. It seems to have sorted the problem, but we have to be mindful of where to put fixings in the wall.

As for damp meters they seem to say whatever the contractor want them to.

 

[Mr Impedance]

I dont know if this will help but I had a similar problem in my kitchen. It had a DPC about 8 Years ago but it had not lasted. So I had a few quotes what a rip off, so I decided to go it alone hacked the plaster off then drilled a new hole (10mm I think it was) in the brick directly above the old. Hired the DPC injector (HSS) and the plugs. Then got it plastered and I have had no problem with it. I did have to put a bit bigger skirting on but it must off saved me £600. Also there is a new electric pulse DPC around a bit pricey thou . http://www.diydoctor.org.uk/projects/dealingrisingdamp.htm

 

[oilman]

BEFORE YOU DO ANYTHING have a look here . There are many people here who can offer very good advice. So many older buildings are damaged by work which is supposed to cure damp problems and "rising damp" (which probably doesen't exist anyway).

You could well do with reading a little book called "Dampness in Buildings" published by Butterworths. ISBN 0-408-01463-6. I don't agree with everything in it, but it will give you a good understanding of damp.

Most moisture in a building comes from inside, people cooking, washing and, worst of all BREATHING!!! Ventilation is the cure for these "problems", NOT waterproofing the walls. There are two major trouble makers for buildings (apart from ignorant damp surveyors) one is hard cement render and the other is masonery paint. Just think, your building has stood since 1887 (our house is about the same age) It has done ok without "modern" treatments, and it probably doesen't need anything more than good ventilation.

What construction materials are used? I suspect it's lime mortar. If you are going to have your walls skimmed, seriously consider having it done using lime and NOT gypsum plaster. Lime breathes and is compatible with your building, gypsum doesn't ansd isn't. Do they even NEED skimming?