Is this damp from outside or is it a heating system leak?

[noseall]

If it were dampness from outside then you would notice a 'waxing and waning' as to when it is wet outside or dry.

There is simply too much water there present to be down to external damp ingress.

I don't know what photos the rest have been looking at but that wall has never been remotely dry.

You have a pipe leak!

 

[maltaron]

I can see that you are confused - you will allways get different opinions as none of us can see the problem "in the flesh". But to repeat, you should have a warranty and it is really a problem your builder should sort out.

 

[blueharvester]

I can see that you are confused - you will allways get different opinions as none of us can see the problem "in the flesh". But to repeat, you should have a warranty and it is really a problem your builder should sort out.

I know guys, and I really appreciate your opinions.

My builder says if it's a pipe leak then the 10 year warranty wont cover it, it will only cover structural defects, not plumbing.

 

[alittlerespect]

Hi

Regretfully, the nature of the defects are such that there is no easy solution to your problems.

The internal detail shown in your photographs is definitely a 'no goer', but you need to determine where the damp is coming from, otherwise you will do repairs and still have a problem.

The amount of water you are losing from the header tank would dictate that you have a leak in the central heating pipework and the most likely culprit would be a joint where the new sunroom meets the existing structure, or where the pipework may change direction when it comes into the sunroom as the pipework may have been run around the perimeter edge of the room - you have no choice other than to carefully breakout the concrete to expose the pipework.

You will then need to follow the pipework to find the joint that is leaking.

Once sorted, use copious amounts of 'crazy foam' to fill the gap shown in the cavity wall - then leave to dry out before reinstating skirtings etc.

Regards

 

[blueharvester]

...The internal detail shown in your photographs is definitely a 'no goer'...

When you say 'no goer' do you mean that the red brick should not be there i.e. the builder should have cornered or 'cut-in' the extension wall and made the cavity continuous? As in this photo.

 

[alittlerespect]

The cavity detail is only part of the problem - I would suggest from the photo's that the builder has added on the walls to the extension directly from the existing face brickwork, but what they had not considered was 'how' to close of the cavity.
Ideally, the face brickwork should have been cut back to expose the internal blockwork, then the foundations could have been laid to allow the internal blockwork to be extended into the extension, likewise the external brickwork.

To resolve this problem you would need to cut back the offending face brickwork to where it meets the internal face of the new face brickwork to the extension, trim back the insulation and then extend the internal blockwork to meet and tie in with the internal blockwork to the main house - not forgetting dpc's and additional bit of insulation.

When it comes to tying in the walls - take a look at and get some advice from the following web site:- www.helifix.com

Fiddly, but do-able!

However, this still leaves you with the damp problem to contend with! You could add some weep hole vents which may alleviate the problem but it would not get rid of it, so you will be back to my earlier comments on that subject

And to answer your question - correct, if I had viewed the photo first I could have saved myself some time! drat!!

Hi! Just noticed one almighty glitch in the cunning plan - you will need to cut back the existing internal blockwork to gain access to the offending brickwork, which brings into play support for the lintel above the opening while the work is being carried out, not a major problem but needs to be considered! Then take the new section of blockwork into the building line and tie into the existing blockwork through the face of the new blockwork - using helifix ties. Not quite as simple as it sounds, but as before it is do-able!

Regards

 

[garyo]

How common is it to not cut in to the cavity when building extensions - I don't intend to for my front extension, and see it as more of a thermal bridge problem than a damp problem :-S