Rising Damp- New house

Endaaaagh · 10-08-2016 2:01pm #1

I’m having issues with rising damp in a relatively new house (6 years). It seems to be more prominent on the internal walls going down the centre of my house (the hallway). I’ve done a bit of research and read that this should be stopped by the membrane under the blocks. I’m stumped as to where this could be coming from.
I think the reason could be that I have been trying to save money the last year by being selective about where I heat the house and would have left the heat off in the hall a lot. Could this be the cause?

Metric Tensor · 10-08-2016 2:29pm

"Rising Damp" is not anywhere near as prevalent as people think. Can you post a picture? You may just have dampness of the non-rising variety!

It's been quite a few years since I've seen a house where the builder left out the DPC at the bottom of the wall and that was the case of a "cowboy".

If you genuinely have dampness rising up the walls you may have a leaky pipe in your floor screed.

Ventilation and appropriately managing the internal environment are keys to avoiding dampness. If your hallway was particularly cold and the room adjacent to it was warm then you could easily get condensation forming on the cold side of the wall - hence dampness (of the non rising variety!) Mind you I doubt your hallway was THAT cold - see paragraph below.

It's a false economy turning off the heat in a hallway because the degree of interaction between it and the surrounding rooms means that the heating in the surrounding rooms will just have to work harder as they are trying to heat the hallway too.

Hallway and spare bedrooms at 16-18. Used bedrooms at 18 and main living area at 20ish. In a six year old house heating the hallway should cost you f all anyway.

Pictures would tell a lot!

Endaaaagh · 10-08-2016 4:04pm

Thanks I'll get some pic up when I get home later.
The issue is the paint is starting to blister and bubble along the top of the skirting board in the hallway and is some parts of the kitchen (on the opposite side of the hall wall. I do have a small pantry off the hall which I never painted where I can see the opposite side of the wall clearly and it there is a definite dark shadow rising up from the bottom..pics to follow

raypallas · 10-08-2016 10:04pm

Sounds like a water leak, had similar on an internal wall in the home place last year. Could be a leaky pipe on a radiator as ours was

Metric Tensor · 10-08-2016 11:12pm

Exactly what raypallas says - it sounds like a leaking pipe to me too!

Calahonda52 · 11-08-2016 10:26am

Op: we are celebrating 100 years of rising...:D
I had a similar one to this: problem was driving rain under the Alu door saddle, took two years to find it.
It remains the outlier on my reasons for "damp"

OP: is the heating system open or sealed: if sealed is there pressure loss on the gauge?

Check behind the washing machines, dishwashers etc for drips

Endaaaagh · 11-08-2016 10:32am

Thanks for all the replies folks. See attached pics.
Pic 1 is taken about half way down the hall. This wall is the reverse of the wall seen in pic 2 which is my pantry/storeroom. The main bathroom is just to the left in the attached pic
Pic 3 is taken out near the front of the hall (my hall is "L" shaped). On the opposite side of that wall is a bedroom. This is on at least 3-4 meters away from pic one which is on the opposite side of the hall.

One note, I have been drying clothes on a clothes horse in the hall for the last 10 months or so. Could this have caused this issue (I've since stopped doing this)

Endaaaagh · 11-08-2016 10:38am

Calahonda52 wrote: »

Op: we are celebrating 100 years of rising...:D
I had a similar one to this: problem was driving rain under the Alu door saddle, took two years to find it.
It remains the outlier on my reasons for "damp"

OP: is the heating system open or sealed: if sealed is there pressure loss on the gauge?

Check behind the washing machines, dishwashers etc for drips

It's an open system, fed from a tank in the attic.
I recently found & repaired a small leak behind the sink in the bathroom. I only discovered it when I heard water dripping one morning and discovered a leak in one of the pipes going up to the tank. It was dripping directly onto an open part of the floor behind the sink with no tiles with the screed exposed. That has since been fixed but it is at least 3 meters from the walls where I'm seeing the leaks.

Metric Tensor · 11-08-2016 10:52am

Yes drying clothes indoors can cause dampness problems and should be stopped as much as possible - but having said that I don't think it could have caused the problem you show in the pictures.

I still think a leak is the most likely candidate. A few suggestions:

1. Close the ballcock in your open feed CH system and see does the water level begin to drop gradually. This will tell you if a CH pipe is leaking.

2. Then do the same with the domestic water tank and that will tell you if a pipe to any of the gravity fed sinks or toilets is leaking. (N.B. Kitchen taps are fed from the rising main so it's not possible to test that by this method. Also make sure you don't have any appliances running or using water or the test will be useless - obviously!)

3. Do I see a linoleum floor in the store room? Any chance of peeling it back to check if the floor screed is wet next to the wall and if it is ideally follow the dampness as far as you can.

Endaaaagh · 11-08-2016 11:46am

Metric Tensor wrote: »

Yes drying clothes indoors can cause dampness problems and should be stopped as much as possible - but having said that I don't think it could have caused the problem you show in the pictures.

I still think a leak is the most likely candidate. A few suggestions:

1. Close the ballcock in your open feed CH system and see does the water level begin to drop gradually. This will tell you if a CH pipe is leaking.

2. Then do the same with the domestic water tank and that will tell you if a pipe to any of the gravity fed sinks or toilets is leaking. (N.B. Kitchen taps are fed from the rising main so it's not possible to test that by this method. Also make sure you don't have any appliances running or using water or the test will be useless - obviously!)

3. Do I see a linoleum floor in the store room? Any chance of peeling it back to check if the floor screed is wet next to the wall and if it is ideally follow the dampness as far as you can.

Thanks, I'll give the above a go.
No that's not lino in the storeroom, the floor is tiled. I've been onto a carpenter mate of mine to see about taking up the floor in the hall to see if we can trace a leak (it's a floating floor on batons). Hopefully if there is a leak, it's there. The bathroom floor is screed and tiled so it will be a bigger job to take that up

Metric Tensor · 11-08-2016 11:54am

There are specialists that can do leak detection to narrow down the location of the leak but it's not an exact science.

And of course none of are certain that it is a leak!!!

Calahonda52 · 11-08-2016 1:09pm

Leak deffo, identical to the issue I referred to earlier

Good idea to get the floor lifted in hall and do check the door saddle:)
re the rising main, if you have water meter or stop cock on the road turn it off there.

Once you get it sorted you may want to rent a dehumidifier for a while to help get the damp out.
Don't run it too hard as you may warp some of the timbers.

There are also stop cocks in the hot press that can be used to isolate hot and no rising main cold, however make sure you know whats what as one of them may be the CH boiler by pass: post some pics if u want.

Endaaaagh · 11-08-2016 2:50pm

Thanks for all the advice folks. I'm going to try shutting off the water and monitoring the levels.

tedimc · 18-08-2016 11:31pm

I know it's a week ago since you posted, so may not be still relevant but I was talking to an UFH installer yesterday who was telling me about a leak detection system where they fill the pipes with Hydrogen.

Apparently Hydrogen is the smallest atom and can usually absorb through most materials like concrete, tile, etc. The guy then goes around the house with a detector and can pinpoint the source of the leak to within a few inches.

May be worth a look if you still haven't found the source.

Metric Tensor · 19-08-2016 12:39am

If he went around with a cigarette the mushroom cloud would allow us all to pinpoint the leak!

Hydrogen is indeed the smallest atom - but it's flipping awful explosive! Helium is the second smallest and a LOT safer.

I wouldn't like to risk pumping all my floors full of hydrogen - especially if I knew there was a leak!!!

tedimc · 19-08-2016 1:17am

I know - we had a couple of jokes about that one as well. I presume it dissipates fairly rapidly, but I wouldn't be lighting the barbie too soon afterwards anyway.

jace_da_face · 09-04-2018 10:29pm

OP, did you ever get to the bottom of this? I'm seeing the exact same problems in the last week or so.

jace_da_face · 05-09-2019 5:10pm

I still haven't got to the bottom of what looks like rising damp on internal walls, one a hall to living room partition and the other a double cavity living room wall to external. All on ground floor.

So I read a lot of opinion that says rising damp is a myth such as on this site https://www.heritage-house.org/ which states:-

"Rising damp is a wonderful marketing tool used to sell millions of pounds worth of worthless chemicals and labour to an unsuspecting public, irreparably damaging structural brickwork in the process, and don't forget that they always want to re-plaster the walls with impermeable plaster - this just makes the problem come back in ten years or so..! Great for business if you're flogging rising damp treatments...."

I find this really disconcerting as I don't know what to believe and I would really just like to get it sorted at this stage. Any opinions on this? I dont want to call in an expert who makes his living treating rising damp if I can't trust what is being said.

In the meantime I will look into possible leaks. Any ideas of good companies to call in Galway area?

Calahonda52 · 05-09-2019 5:14pm

We need a bit of intelligence here on the exit problem you have, post some pictures.
Good companies for what?
Have you checjked that no driving rain is coming under the door saddle?

jace_da_face · 05-09-2019 6:09pm

Calahonda52 wrote: »

We need a bit of intelligence here on the exit problem you have, post some pictures.
Good companies for what?
Have you checjked that no driving rain is coming under the door saddle?

Thanks for your reply. I have two questions really. The first was, any opinions on rising damp, does it exist or not?

The second was in reference to looking for leaks. Any recommendations on good companies to search for a leak?

If you want to see a pictures, I'll get back to you. Regarding the door saddle, I guess that must be a vulnerable spot then? Mine looks normal so I wouldn't know what to look for. Does driving rain find a way through under the threshold slab because there is no boundary wall to bock it?

jace_da_face · 06-09-2019 9:18am

This is an internal partition wall. The first evidence of a problem was covered over last year, following an unblocking of a drain and some wishful thinking that the problem was resolved. Recently it reoccured above the original tide mark. It now sits above last year's damp proof paint job.

This is the front door threshold. It looks normal to me.

JonathonS · 07-09-2019 12:49pm

jace_da_face wrote: »

any opinions on rising damp, does it exist or not?

It may exist, but as pointed out above it is rare. So rare in fact that it will almost never be the cause of a damp problem. Google "The Fraud of Rising Damp" to get a link to a UK site that goes into a lot of detail. Do the same search in YouTube to see a multitude of videos by the same chap.

jace_da_face · 09-10-2019 4:19pm

Well it looks like I got to the bottom of my ‘rising damp’. A leak under the sink in a kitchen island unit. All down to how a reverse osmosis unit was installed years ago. The technician who installed it pierced and clamped into a cold water copper pipe. Lazy b****r. Doing my water meter calculations, there was probable about a liter of water per day going into my screed floor. This could have been happening for a couple of years.

Safehands · 24-10-2019 9:22pm

jace_da_face wrote: »

Well it looks like I got to the bottom of my ‘rising damp’. A leak under the sink in a kitchen island unit. All down to how a reverse osmosis unit was installed years ago. The technician who installed it pierced and clamped into a cold water copper pipe. Lazy b****r. Doing my water meter calculations, there was probable about a liter of water per day going into my screed floor. This could have been happening for a couple of years.

A very interesting problem. Rising damp does happen, mostly in external walls, in older buildings, never on interior wooden partition walls. When it occurs it never rises more than about 1mt in height. It does cause the paint or wallpaper to come off, whereas condensation does not. Rising damp occurs in brick or rubble walls where ground dampness is "sucked" into the structure, causing the bottom section to become damp. I agree that there is a bit of a con job by some companies using silicates to "block" the dampness. It is simply impossible to know the make up of the mortar joints, or random rubble in the wall. So to say with certainty that they are being "injected" with a silicate which will make them watertight, is ridiculous. Blocked drains or damaged gutters or downpipes, or other leaks are quite often responsible for the ground below walls to become soaked causing dampness to penetrate walls. A high water table can also cause problems.

These damp proofing companies usually also apply a waterproof coating to the wall in addition to the injection and that is usually what keeps the damp at bay. Identifyng a fault or leak and repairing it can also solve many rising damp problems.

Rising Damp- New house

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