Problem with New Extension

[pj123]

We are having an extension built to the side of our house

The wall, built from concrete blocks is right against the boundary wall (also made of rendered concrete blocks)

There is a 2 inch gap between the walls. It is clear that moisture is still building up in the walls.

We know one reason is the poor quality gutters that have been installed. There is a gap between each length of gutter which he has filled with sealant!

He has also not applied the render on the outside wall completely. This was because he did not remove the wooden fence that sits on top of the garden wall to give him access to the outside wall

We will get him to fix these two issues tomorrow but I am not sure what is the best way to manage this narrow gap between the walls

I suggested that he use render to cover the top of the gap. See in photos but I am not sure if this is the best way as there may be some cracking in that render later and water will leak through.

Another problem (I think) is the position of the downpipes for the gutter. They are not at either end but in the middle. He did this as the drains run parallel to this wall so the  rain water will flow directly into the drain 

Advice appreciated.

[thaitom]

It looks like cheap construction, I personally would just tear it all out(down)

and build new.

[Tuvoc]

It seems most Thai houses don't have guttering at all. Rural anyway. No doubt because there is nowhere for the water to go.

[bbko]

Repair the rain gutters correctly and maybe get rid of the smartboard, apply a concrete sealant that repels water. 

[Kwasaki]

The high gutter obviously needs to be addressed and remedial work done. 

 

The next intermediate level where the downpipe goes into I cannot see a detail or how it's weathered to the wall. 

 

The lower level needs ship lapping planking fixed to the existing steelwork down to the existing top of wall. 

 

The small gap between the wall should have been filled with waterproof cement mix. 

[worgeordie]

Legally you are not allowed to build right up to a neighbor's house

like that , there has to be a certain distant from the wall, and it's not 2 inches,

hope you have good neighbours.....

regards worgeordie

 

 

[Yellowtail]

Fill the gap between the walls with PU foam and mortar over it. 

[sometimewoodworker]

Be absolutely sure you are not letting any of your roof water hit your neighbours property.
 

You can be taken to court and forced to set back the legal minimum that is at least 1 metre and in some cases 2 metres. If your rain water is hitting your neighbours then there is a good chance you will end up in court. 
 

[pj123]

Thank you for all the replies. I think whatever we do we will have ongoing issues with dampness. What about installing a tanking system ( inside the room) on that wall to prevent moisture penetrating?

[pj123]

Tanking slurry? This material can be plastered over and painted. Needs a special bonding agent between the slurry and the plaster and you need to use permeable emulsion paint.