Waterproof Balcony Floor

[Ambaz79]

Hello,

 

We have built a balcony that is above out Living room. Basically we have cerated the balcony by setting back the bedroom wall by around 1.2M.  We have then tiled the floor however we are still getting water leaking through the living room ceiling.  When the wind blows towards the house thats really only when water gets into the balcony and then leaks.  We do have a drain but its really of no use as the water does not really get to a level where is can move towards the drain.  Mostly we get very shallow pools of water on either side of the drain and then drips down onto the living room ceiling.

 

Whats the best way to either waterproof the tiles so it 100% stops the water or redo the flooring to become 100% waterproof.  Needs to be something that is ok with the sun too as we are south facing. 

 

Thanks in advance.

[Mr Punter]

Well the good news is that it looks really good.

 

You have issues with the failed drainage and waterproofing, so I think you need a redesign of these aspects.  If it is just the drainage, you may be able to leave the tiles, otherwise, probably strip and start again.  You really should have more than one rainwater outlet here or at least have it so any surplus water would run off the front of the balcony rather than into the building.

 

GPR is good on flat roofs and if specified correctly should be ok to tile onto.

[Ambaz79]

Hi @Mr Punter thank you 👍

 

Water can't run out the front as we are a block higher on the front wall. I think the water is going through the grout and then leaking. Maybe very tiny cracks in grout due to the external tempreture causing expansion etc. 

 

Is there anyway to seal the tiles and make the grout water proof. 

 

Also can I just finish the floor with gpr? 

[oliwoodings]

3 minutes ago, Ambaz79 said:

Hi @Mr Punter thank you 👍

 

Water can't run out the front as we are a block higher on the front wall. I think the water is going through the grout and then leaking. Maybe very tiny cracks in grout due to the external tempreture causing expansion etc. 

 

Is there anyway to seal the tiles and make the grout water proof. 

 

Also can I just finish the floor with gpr? 

 

You can't really think of the tiles themselves as a perfect waterproofing layer. Grout fails over time, surface sealants wear out etc. Your flat roof substrate underneath the tiles is what needs to be bulletproof.

 

If water is coming through then it suggests an issue with that substrate - either it's failed, or been installed poorly leaving a route for water to get through. Do you know what's underneath the tiles?

 

Is it too late to get whoever did the work back to fix the issue?

[Ambaz79]

Hi @oliwoodings

 

The builder that did this has gone now. So it's on me to get sorted.

 

You see the other problem I don't want is the water sitting under the tiles. 

 

Then the builder did the floor he first painted a black Waterproof paint and then put mesh down and then painted on it again. This was meant to make the floor water proof. 

 

I think even now the water goes through the grout and then sits on the black waterproof coat and the once enough water is there it makes its way down. 

 

Is there another flooring that I could do her either on top or redoing the whole thing. 

[Ambaz79]

[oliwoodings]

How long ago was this done? If it's within a year I think you'd be well within your rights to get them back to fix it.

[oliwoodings]

Another thought - you seem certain it's the balcony floor that's causing the leak downstairs, but could it also be the doors/windows? They might not be properly sealed, for example. You mentioned it only happens with high winds, which could support this theory.

 

Do you have any pictures of the leak from downstairs?

[Conor]

I think the issue here is the upstands.... Or lack of. You really want the tanking and thresholds a good 200mm above the tanked surface. Or the door /cladding thresholds. Where does water go if it teachers the threshold at the door?

[Mr Punter]

Having seen the extra photos I have not got any useful suggestions I am afraid.

 

Getting a balcony like this, with habitable space below and closed at the front and sides, needs very careful planning and detailed design and specification, which it did not have.

 

If it is left as is there could well be major damage because of water ingress.  I think you should get a specialist designer and have it redone.

[ADLIan]

Thinking of it as a balcony floor is missing the point. It’s a flat roof to the room below and as such should have proper waterproofing, correct falls & drainage and be insulated. 

[Andehh]

I'd be tempted to drop the ceiling below where the wlqks are, and see if you can spot the water. That might identify if it is the rain, upstand, grout etc to give yourself a starting point!

[Ambaz79]

I know roughly where the water is leaking from.  its on either side of the drain where the water sits as there is not enough of a drop towards the drain.  

 

If I did just treat this as a flat roof and for example install a EPDM Rubber Roofing System ontop of the tile and cut out the drains.  Would this be ok first of all to be fitted onto the tiles that are already there? Secondly could we walk on this.  This is a very low traffic area as you can imagine.  I go out every now and then but normally without shoes on.  

 

Also I dont think the upstands are an issue as there is no leaving around the edges of the balcony.  

[kandgmitchell]

Unless there's reasonable fall into that drain then the water is just going to pond, will you be able to dress the EPDM into the drain enough to stop water seeping back under the new sheeting? You might find balck EDPM gets very hot in the sun for bare feet!

[oliwoodings]

13 hours ago, Ambaz79 said:

I know roughly where the water is leaking from.  its on either side of the drain where the water sits as there is not enough of a drop towards the drain.  

 

If I did just treat this as a flat roof and for example install a EPDM Rubber Roofing System ontop of the tile and cut out the drains.  Would this be ok first of all to be fitted onto the tiles that are already there? Secondly could we walk on this.  This is a very low traffic area as you can imagine.  I go out every now and then but normally without shoes on.  

 

Also I dont think the upstands are an issue as there is no leaving around the edges of the balcony.  

How close to the drain is the leak? From your photos, seems like it could be the installation of the drain and the way it's been sealed that's failing? I.e. in your original photos, could it be leaking around that blue tape?

 

EPDM over the top sounds like a cheap tacky solution that will be hard to make attractive at all. Really the tiles need taking up and the waterproofing fixed properly, before a new finish is done (tiles/grp/EPDM).

[Andehh]

I wonder if you could retank the whole area, then lay new tiles over the top? If low traffic, structurally sound... I see no reason why it wouldnt work.

Edited May 8 by Andehh

[Ambaz79]

a few soluitons I have now.

 

Go over the exhisting tiles.

1, Put something over the tiles to create a fall into the drain ( some sort of concrete or something to create the fall)

2, Put EPDM over this so the water now falls towards the drain and cut out the EPDM at the drain.

3, Tile over this again leaving a passage in the adhesive where the water can get to the drain. Or use pedastals to put the tiles on so there is a clear way for the water to get to the drain.

 

Rip out old tiles

1, Keep drain where it is but take off all the tiles

2, using plywood or OSB to create a fall towards the drain.  I could use tapere wood thats used to create a fall on flat roofs and then put the OSB ontop of this.

3, tile over this and create a level floor.

 

Where the door and Windows are they are fitted on a peice of timber so they are already around 40mm higher then the tiled floor.  So if I raised the level outside it should not be a problem. 

 

 

 

[scottishjohn]

On 08/05/2024 at 12:16, Ambaz79 said:

Rip out old tiles

1, Keep drain where it is but take off all the tiles

2, using plywood or OSB to create a fall towards the drain.  I could use tapere wood thats used to create a fall on flat roofs and then put the OSB ontop of this.

3, tile over this and create a level floor.

grp  it all with upstands at wall  

your main problem is the lack of height at the door sill to get a good seal to building 

 how thick are your tiles ?

my humugus balcony was done like that with lead flashing coming down over the grp 

is there neough space to raggle some lead below the window area  when tiles are removed ?

 

 final thought where are the window bottom channel drains going to  cos it will gather up there as it runs down the windows,myabe laeking from there to lower floor 

god forbid it is from the pipework from your balcony drain 

 

 you could go old school and once tiles are up use hot tar toseal it then retile

 sounds like you need to remove plaster board from room below -to watch where it comes in maybe

plaster board will be knackwered anyway soon

Edited May 16 by scottishjohn