Cavity wall cut out extension damp

[swes]

Hi people,
I own a three bed semi with garage that I have just converted to living space.
I had to cut out my gable end to create an opening, which I made good temporarily. Since we have had some rain I have noticed a damp patch coming from the top of the opening.today I have cut it out to find damp and occasional drips down the inside of the external wall.see pics. The garage roof had been completely replace with a rubber roof so I don't think this is an issue .
My questions are.
Is there a cavity closure of some description that can channel damp away?.
Could this be coming from further above.
Any investigations I should do before I start getting a builder in to check this.
Thanks in advanced.....

 

[swes]

Sorry pics arnt uploading atm

 

[freddiemercurystwin]

Just upload your pic to your DIYnot album and post it from there rather than faffing about with external hosting sites.

 

[freddiemercurystwin]

External leaf’s of cavity walls are often not waterproof and some rain water can get through, more of a problem if the external leaf is brick. Retro-fitting a cavity closer above the opening is the best solution. Though no doubt the lame people on here will tell you to faff about with various sealers of mess about with the pointing. Though the pointing could be an issue. Got some photos of the external wall too? Show the issue in context not just a photos of some drips.

 

[Alastairreid]

Google cavity trays.

 

[theprinceofdarkness]

No pics!. If your garage is a lean to type with your opening into it, which is leaking. This would mean that the outside skin of the wall is wet and in the garage it is now an internal wall. I don't think a cavity tray will sort this out.
Frank

 

[freddiemercurystwin]

A retrofitted tray above the flashing for the flatty would undoubtedly sort this out.

We need some clarification OP ......

 

[swes]

Hi here are a few vague pics. Garage is flat roof . I was thinking of Flashing some lead above existing capping that has been cut already. Having spoke to building control I believe it might be an issue with the installation. If so my roofer will have to sort and pay for all damage . So the lead,I was thinking of cutting a new slice above existing cap and fitting new lead right through into cavity and moulding inside to Chanel damp left and right. Folding external lead down over capping outside.. Any probs with that ? Zxxxxxc

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• swes
• 11 Dec 2014
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• 11 Dec 2014
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• swes
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• swes
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[Alastairreid]

Just as easy installing proper cavity trays.

 

[freddiemercurystwin]

Yes that seems an odd solution, just retrofit a proper retrofit cavity tray if you're gonna do that.

Its not mandatory for such a tray to be fitted when converting a garage like this so doubtful your builder will cough up for that. Arguably he could have suggested fitting one. If I was doing the drawings I would have recommended its fitment but that doesn't mean one would be fitted, though bit of a moot point anyway as I very rarely do regs drawings for garage conversions.