Another Bloody Damp Question!

[Barry505]

Hello All,

I have damp in my kitchen area, please see the link below for a diagram of how it looks:

I have a roofing guy coming around next week to see if there is any ingress of water from the roof or old, unused and sealed chimney.

If there is not water coming in from the roof I'm thinking that it could be coming from the external wall, which is rather high. My question is....

" Can I damp treat the join of the house wall where it meets the external garden dividing wall (i.e. down the vertical join?) Or is this just a stupid idea? I'm on the verge of buying a couple of tube of DryZone which I could stick in there "

Cheers in Advance!!!

 

[Barry505]

Just as a bit more info, this is what it looked like before I stripped it back to brick:

I have also recently dug down to 6inchs around the externals of the wall and put hardcore chippings down.

The plaster wasn't particularly damp and a friend of mine said it looked like some sort of condensation? as you can see the DPC had some effect as the bottom half look okay.

 

[KenGMac]

Barry505, Hi.

Interesting problem?

Because of the start point on the rear external wall it would appear that we are not looking at "rising damp" rising damp can not get above about a Meter high above floor level, capillary attraction can not support moisture above this height.

As a stab in the dark? I am assuming that your house as described here is not a "new build" I am assuming that your home is about 70 to 100 Years old?

Another "assumption?" is that the external garden wall is some 300.mm thick?

If so? then this external garden wall could be, absorbing rain water and transferring the moisture into the main Property rear wall, the height of what could be "penetrating" dampness may be in line with the top of the external garden wall?

Some more info based on the above would be of interest , Please?

Ken.

 

[Barry505]

Thanks for your response Ken,

All of your assumptions are correct:

- House 100 yo terrace in York, the extension where the damp is is probably more like 70-80 yo??

- Garden wall 300mm from GL to half way up and then reduces to 150 (ish)

- Dampness is around this area predominantly but also stretching to boiler area (see photo below)

- External wall is rendered (ill try and post another pic of this later)

 

[Barry505]

This is a close up of some of the brick work which is on the side of the neighboring house. As you can see there are four uniform gaps in the brick work (right) and a large drill hole (left). No sure if these are causing any problems. Might have been securing a cistern back in the day!?!

Cheers

 

[Barry505]

Outside walls.

Single skin thickness on the back wall I think.

Thanks

 

[foxhole]

Looks like ext wall was extended up at some stage, probably no dpc causing bridging.Additionally render will prevent it drying out.

 

[joe-90]

Looks like a typical example of interstitial condensation to me.

 

[Barry505]

If the DPC had been bridged would there not be damage to the plaster at the foot/lower half of the wall?

Do you think that they might have put the render on in an attempt to keep the temperatures at less extremes? The brick work to the right of the render is in good condition externally (on the surface) so I don't see why else you would render?

Although we have none of these problems with this other brick work (to the right) these seem to have cavity walls, which that back wall doesn't.

If Interstitial Condensation is the problem, is Kingspan insulated wall systems the only way forward? If I was to remove the external render and tank the interior wall before finishing plaster would this have any benefit?

Its an extra headache because the boilers on that wall, so anything that I do has to take this into consideration.

Cheers

 

[Barry505]

Is this the cause of my problems?

 

[KenGMac]

Barry, hi [again]

Really good photo, makes a change

I for one am deeply "suspicious" about several things on this Photo, it would appear that "historically" your Neighbours property had some sort of Lean-To "Structure" attaching to the rear wall of what is now his Bathroom? the waterproof "flashing" has [at that time] been that cheap jack C--p "Flashband" a silver foil that is sticky on one side and has the foil waterproof coating on the other. As a VERY temporary "repair" it is OK but as a full time Lead replacement it is not a good idea [ I have chosen my words here as I do not want to get Sued by the manufacturer of this material]

Looking at what we got?
1/. Not rising damp because the "damp patches" start too far up the wall, rising damp cannot get to a height above about 1.00 M 1.10.M MAX, Capillary attraction cannot support water above this height.
2/. Interstitial Condensation? tends to be seen in corners of "cold rooms" and at the junction of ceilings and walls, happens when the surface temperature of the wall allows the moisture in the air in the room to hit its "dew Point" [ A temperature at which any "free water" in the air inside a property will condense on a cold surface]
3/. So by a "form of" a process of "elimination" we arrive at penetrating dampness?

In the photo you provided last, the Flashband COULD be allowing rain water to land on it and be channelled into your Property?

There is a bit of "metal" seen on your neighbours side of the wall, this too could be allowing rain water to get into your Property?

it appears that some of the Brickwork horizontal joints at the junction of the two properties may be "open" where the cement has shrunk and could allow water to enter your Property?

finally [just to let others get a bite at this problem] there appears to be a "hole" in the cement render directly above the top brick in the Garden wall

Hope some of the "ramblings" above assist, or at least point you in a direction?

Ken.

 

[Architexeter]

From what I can see, yes the detailing of this area is cr@p and there are several positions for potential moisture ingress and this is making the wall damp...
BUT:
To me this appears to be a classic case of room humidity.
First question, do you have an extractor in your kitchen? I'm going to assume no.

Generally living in a house you generate water vapour in may ways - water vapour wants to condensate and will try to find a cold surface so that it can do. Back when we all had single glazed windows it was a no brainer for the water vapour, it went "Brilliant, cold window, thanks very much" and you had a puddle on your sill. Nowadays this in not the case and water vapour will float around and condensate on the next coldest thing - voila - your poorly constructed and slightly damp wall (damp walls are more of a thermal bridge than dry walls).

Verdict:
1. Improve detailing in this area where you can, DPC up boundary wall junction would help
2. Fit extractor in kitchen and bathrooms and use them!
3. Heat - keeps water vapour in vapour form longer until the extractor can suck it out. Plus will help dry out wall
4. Insulate (Ideally higher priority but is the biggest job).

 

[Barry505]

That's great, Thank-you for your help and suggestions. I'm fitting a new kitchen in the next 6-8 weeks and therefore I'm keen to get this problem sorted before doing so. I will take on board what you have said and will take some time off work in the coming weeks to put all of this into action.

Just as a bit of information further to that above, the kitchen doesn't have an extractor fan but I have a sparky coming to wire one in next week.

Thanks again.

Barry