Penetrating rain through gable wall - will this work?

[JimExtension]

Hi all,
We are getting penetrating rain coming in through our gable wall. The gable is made of block work added for a hip to gable loft extension, with a very thin concrete render over the top.
There is some cracking visible as seen in the photo.

We are thinking of the following solution:

1. Fill in the main visible cracks - rake them out / fill them in.
2. Paint the gable with a weather proof paint - e.g. Dulux Weathershield.
3. Clad the gable with something like Cedral Click cladding.

Does this sound like a plan likely to succeed - at least for this section of the wall?
Thank you.

 

[robinbanks]

It's a solid blockwork wall? No cavity?

 

[JimExtension]

On the other side in the loft room the wall is made of plasterboard. The loft was only constructed about 5 years ago (before we moved in) so I’m hoping there is insulation between the plasterboard and the block work wall as well.
It did have building control approval so should be a standard loft conversion construction. I hope!

 

[tell80]

Are you saying that you have a blockwork outer skin - stud framing - plasterboard? No mention of a cavity or vapour barrier or knowledge of any insulation anywhere in the wall?
When did you first notice the interior damp signs?
Water entering behind the render will eventually blow the render - so look for slightly bulging render .
The thin coat of render is obviously too skimpy and almost useless.
Ignore your other suggestions and rake out, and (after reading the instructions) fill with polysulphide sealant - then see how it goes.
Pics showing the inside water damage signs might help?

 

[JimExtension]

Yes blockwork outer skin, studwork, and plasterboard.

I’d believe there is insulation in there too, but as the walls are sealed up I can’t see what is inside. The loft seems warm enough!

The interior damp has been slowly appearing for the last 2-3 years. I’m attaching a few photos - it would look worse (much more yellow patches), but every so often I paint it over again. The water damage is in more areas too, all on the upper part of the 1st floor on the gable wall.

The attached photos are from the 1st floor below the loft. My theory is that the water is coming through the blockwork (or perhaps there is condensation dripping down the inside of the cavity?), and the that water runs down the loft cavity until it hits the solid brick wall that forms the 1st floor. And there it is soaking into the bricks and coming out internally in the 1st floor wall.

Does any of that sound plausible?

 

[Alastairreid]

Pic of the gable would help.

 

[tell80]

Where were the pics in post #5 taken? Presuming that they show the dormer gable wall interior then why not cut them out ie cut out squares of plasterboard from stud to stud. Mark cut lines & use a knife.
You will then hopefully see how it is with the framing and the blockwork - take a pic & post it.

Thank you for showing a previous pic of the gable in your original post #1 - the pic labelled "gable main crack".
It was helpful.

 

[Alastairreid]

As long as the render is sound masonry paint will stop the water ingress, ditto cladding.

 

[tell80]

Masonry paint will do nothing for cracked render except cause expense.
As the OP's post #1 pic says: "gable main crack" implying that there are other cracks in the render.
The OP also shows & notes that the render is "very thin".
To those with experienced eyes the render is a mere skim.
All in all, that does not appear to be a case of: "sound render"?

 

[JimExtension]

Pic of the gable would help.

Here’s a photo of the gable end.
The interior photos are from the 1st floor (the floor below the loft floor) - the water ingress is on the other side of where I applied the bright white Dulux Weathershield paint.

But I’m wondering if water is getting in through the big cracks in the gable and then running down the inside of the loft cavity wall? Then hitting the solid wall that makes up the ground and 1st floor?

 

[Alastairreid]

That pic explains it better! I would agree with your theory it makes sense.
The builders have left a poor finish on the verge next to the dormer, the rainwater will come straight off the roof and down that bit of the gable, they should have installed a bellcast bead along the join of the new render to shed the rainwater run off.
First thing I would do is get the verge sorted out. You can get the gable re- rendered with a bellcast bead installed, clad or painted which would be your cheapest option.

 

[Nige F]

The OP also shows & notes that the render is "very thin".
To those with experienced eyes the render is a mere skim.

So the O.P has experienced eyes too

 

[Nige F]

Oh experienced eyes , Tell80 has the most experienced eyes ,this is just adios and not goodbye. He will return bringing us all us all his B.S ( building services) Please say si si Say you and your experienced eyes will wait for him. - With apologies to Engelbert and Spanish eyes

 

[Alastairreid]

Al Martino.

 

[Nige F]

Him too