Balcony causing water ingress?

[erikwoolf]

Hi all, I have recently bought a Victorian maisonette (Lower and Ground floor). The ground floor has a slate and cast iron balcony overlooking the garden. At the corner of the balcony where it meets the wall I can water marks from what I assume is water running down the side of the balcony when it rains. The wall directly underneath the water marks has damp and the plaster has blown off. On the side of the balcony where it is attached to the wall there also seem to be a small area where the bricks seem to have salts and there is something wrong with the pointing (picture taken from above the balcony). The pipe is the boiler overflow I think.
I am planning to hack off the plaster internally but I was wondering if anyone knows a solution for draining the balcony properly. Is it as easy as installing a gutter? Is there anything else I should be thinking here?

l,

 

[Cubist]

The wall directly underneath the water marks has damp and the plaster has blown off.

I'm assuming you mean the internal plaster has blow off. Are these marks immediately below where the frame of the balcony is embedded in the wall?

 

[88v8]

Hello and welcome.

It's a slightly odd arrangement with the water just running off the edge, perhaps something was done to the balcony when that plastic thing was shoehorned in beneath .... however I think you have little to worry about.

Yes, you could put in a little side gutter to catch the water that is running off the edge. I imagine originally there would have been a raised edge to the balcony so the water ran off the front, and a formed drip on the front so it did not run back underneath.

As regards the blown render ... on the outside of a building it's referred to as render, inside it's plaster ... I think it started to come off years ago and damp got behind it which is why you see the salts, then eventually the frost blew it off. I would just hack off the render and redo it. Brush off the salts first with a stiff brush.

When it was built originally that upstand might have been lead or copper, then when the balcony was resurfaced it was just rendered, I could be wrong. Is there another balcony on the building that might have the original finish?

Anyway, no great problem, I'm glad to say.

Hope you enjoy your new home.

Ivor

 

[erikwoolf]

Thank you Ivor and Cubist, yes the marks are just below where the frame of the balcony is embedded in the wall. The plaster on the inside of the wall has blown off. You can just use your finger in some of the places to take the plaster off.

 

[Cubist]

Hello again Erik,

There are several potential causes for the blown plaster and one of these may be quite serious. You need to investigate further to define the root cause with some confidence before attempting any repair. Sadly, you must remove more of the plaster around the sites where steels from the balcony enter the brickwork. This is essential to determine the final nature and extent of the damage is limited to the effects of water penetration or, in the worst case, severe rustling of the steelwork of the balcony. The latter may seriously impact the structural integrity of the balcony and therefore its safety.

I would strongly suggest that you examine all the points where the balconies steels enter the brickwork and remove the plaster behind each of those locations to see if there has been any damage/degradation.

Cheers,
Cubist

 

[erikwoolf]

Thank you, I will start removing the plaster and see how it goes.
Anastasia

 

[erikwoolf]

I removed almost all the blown plaster, this has essentially resulted in removing all the plaster on the wall just behind the water marks running off the edge of the balcony. Also a big chunk of the plaster on the other side of the balcony where the water drips from the centre of the balcony where the 2 balcony slates join. I am expecting a builder and a structural engineer to get a professional opinion about the structural integrity of the balcony.

 

[Cubist]

Hi Anastasia,

My most worrying concern is whether the steel brackets used to fix the balcony into the wall have been weakened by heavy corrosion. The 'rusty scabs' that can form on the surface of steel are a form of expansion which can in turn 'blow' renders or plaster. Have you been able to examine these yet? Also, have you checked how the builders who constructed that conservatory 'sealed' the back edge of the balcony to prevent water ingress?