Damp / Condensation on Party wall

[KenGMac]

SALL2009, good evening.

Historically, it would appear that.
1/. The partition wall between two rooms has been removed, the timber insert emanating from the large brick pier would have been the line of the original now removed wall.
2/. The mix of a timber floor and the concrete with tiles appears to indicate that there has been a damp problem? when the timber floor and joists have suffered rot attack and been replaced with the concrete floor.
3/. As I see it?? the concrete was placed but? there was a badly installed DPM or no DPM layed below the concrete? or?

What may be happening is that a leak in the Central Heating [as JohnD] above ? is the system gravity fed or is the C/Heating a Combi-Boiler?, if the latter, are you having to re-fill frequently??

it would be of interest to know how thecut ends of the remaining timber floor joists were supported whilst the concrete was being placed? as an aside? does the timber floor "bounce"?

Ken

 

[SALL2009]

I have lifted the boards and there is signs of moisture on the ground but no leak. The source seems to be the far right corner. And there is a drain on the other side.

 

[KenGMac]

SALL2009, Hi.

There is what appears to be an air brick on the external wall above the external drain, which "possibly" ??? indicates that at one time the entire internal floor was of a suspended timber construction??

Also of "interest" is the apparent dampness externally on the bricks above the area of the drain.

Has or does this drain overflow?

As an aside, if indeed the drain is leaking, it would take a CCTV survey to determine that, it will be an Insurance claim to undertake a repair on the underground external drain.

Ken.

 

[SALL2009]

Hi Ken,

Good spot on the air brick above the drain. I'll investigate that tomorrow.
There is another air brick on the right to where the picture ends. The air brick runs to a clay pipe inside the tiled floor and ends where the wooden floor starts.

Both air bricks look the same.

 

[KenGMac]

SALL.

If the "second" air brick runs into what could be considered as a "duct" that will make sense, why? because that air brick will be allowing a flow of air, which the suspended timber floor needs, and allowing this flow of air to "get past" the concreted area of the rooms floor.

Are there any areas externally that are soggy / wet / damp? this could indicate that the external drain is indeed not performing as intended?

Are there "ducts" attached to both air bricks?

Ken

 

[SALL2009]

I need to check the air brick above the drain but I have a feeling it probably runs into duct to the front lounge.

 

[KenGMac]

Hopefully so, why because these ducts, if there are indeed 2 are in effect preventing the build up of dampness in the under floor area of the suspended timber floor and joists in the room.

If so someone historically has at least attempted to ventilate the void under the floor and gat past the obstruction of the concrete.

 

[SALL2009]

Could it just be that the drain is blocked and not actually cracked / damaged?

 

[arkie]

Could it just be that the drain is blocked and not actually cracked / damaged?

If it was just blocked you would see it flooded, pour a bucket of water down it, it will clear in around 30sec if its clear.

Lift the floorboards where the radiator pipes are and check they are dry.

 

[SALL2009]

And the plot twists again. The drain doesn't go into the manhole at all. There is no branch coming into the manhole from that direction.
So it would seem that it's a soakaway. Or just a gully top with no pipe attached to it.

 

[KenGMac]

SALL2009, good evening again.

OK if it were me [glad it is not]

How about considering.


1/. Ask the neighbour if there are any issues in their room?
2/. Has the external cavity wall been retro filled with Insulation? + are there any odd damp spots in other rooms on the external walls?
3/. As previously posted chuck a load of water down the external drain but? use dye to colour the water, then check again under the timber floor for any indications of colour? lift all manhole lids around the property and see if there is any colour in them from the gully? a sort of a tracing system?

Ken

 

[SALL2009]

1. yeah might speak to them at some point.
2. Cavity walls have been insulated. Can't see much issues in other rooms.
3. I have thrown water into the drain and none of it appeared in the manhole that I suspected it was connected to. (can't see any other manholes at the rear of the house)

Does this issue seem quite bad? Part of me thinks what is stopping me from filling in the drain with concrete and directing the water towards the garden (by raising the level slightly on the wall side. )

 

[SALL2009]

Hi Ken,

Spoke to the neighbours today and they don't have any damp issue.
Planning on calling a damp unblocking company in to have a look a try to get an idea of where (if anywhere) the drain goes.

Had a builder around today who recommended removing all the tiled / concreted section and replacing with wooden joist. That would avoid the damp as it will stay below floor level. Obviously still need to sort the root cause.

 

[JohnD]

if the old wooden floor was taken up and filled in with concrete, it's likely to be because it had rotted due to long-term damp.

people who do that often don't repair the fault that is causing the damp.

Along that internal wall it is very likely to be a plumbing leak. Have you got a water meter?

Do you know where the kitchen sink and the indoor stopcock used to be when the house was built?

Sometimes an old boiler or backboiler had pipes concealed in the chimneybreast, that are not correctly disconnected when no longer required.

 

[SALL2009]

Hi JohnD,

Yeah there is a water meter. So I guess I take a reading then leave for a day and see?
Will also pressurise the central heating system and see if it hold the pressure.

The boiler in use is a combi boiler and well away from that area, but there is a switch for a water heater upstairs. So I guess there is a tank in the loft. So time to get on the ladder.

I can probably ask the neighbours about the kitchen sink and the stopcock at the time of the build, however they have only been there since 2000. But currently it is on the other side of the house and connected the main/only manhole (It seems that is the original setup).