Help please - balcony roof leaking - pics included

[Gregory01]

Hi guys and girls.

I hope someone can help give some opinion on how to make my balcony watertight. This is part of a new extension and although I have been happy with most of the building work this is an area I think may have been constructed wrongly?

Basically the roof itself is fine (it's an epdm rubber roof). The problem seems to be that the cavity tray has been installed too high. I would have assumed the cavity tray would have come out directly above the lead Work?

We called the builder back and his initial fix was to paint the block below the cavity tray with bitumen paint and seal the mortar joint with silicone sealant to help stop water coming through it.

I have since done a water test on it by spraying below the cavity tray onto the bitumen coated blocks. The water is coming through in a few areas.

The lead work seems good and the rubber roof comes up the wall by a couple of inches so I can't see it easily getting in there.

Any ideas guys on what I could reasonable expect the builder to do. He has been back 3 times so far trying to fix it and I want a few suggestions so we can get it right 4th time around.

Ps. Worth noting that we are going to render the house. I guess this may help resolve the issue but would rather it was sorted first so I dont have to rely on the render.

Thanks
Greg

Untitled

• Gregory01
• 9 Mar 2015
• 1

Untitled

• Gregory01
• 9 Mar 2015
• 1

 

[Mw Roofline]

Has the rubber been chased properly into the wall (the same chase as the lead) or is it just glued up the wall a bit? If it's chased then the render should more or less cure the problem.

EPDM shouldn't really be used for a balcony/walk area. Despite what people say there is less than 2mm of lining between your feet and the deck!

 

[Gregory01]

Hi MW Roofline.

Thanks for the reply. The rubber roof is not chased into the wall. It goes about 2 inches up the wall and is glued onto the block work. The lead then overlaps this.

I'm not convinced it is getting in between the joints of these and think it is somewhere on the bitumen block and sealant.

Really I want to make sure it is sorted before rendering the wall as I don't want to put the ceiling up downstairs and spend £800 on getting the wall rendered only to find there is still a leak and it all needs to come down.

 

[Nige F]

Hi



Ps. Worth noting that we are going to render the house. I guess this may help resolve the issue but would rather it was sorted first so I dont have to rely on the render.

Thanks
Greg
[ne]

Good point - and the lead is not "good" the way it's marking the rubber with white runoff - all it needed was wiping with patination oil : . Take lead out - fit higher rubber upstand glued to original, refit lead under cav. tray and patination oil it .

 

[Gregory01]

Nige F

Thanks for the reply. I wasn't aware a product was available to stop the White stuff on the leadwork so thanks for the heads up.

I will get the builder back out and put your suggestion to him. My only concern with this is that he will have to be taking the mortar out directly below and around the cavity tray. One wrong move and he might put a hole in it and then we have another problem. Any thoughts or suggestions on this?

 

[Nige F]

Cut into the block under the mortar - then remove the sliver of block and the mortar will come away - shouldn't hurt the tray. Lead can be refixed into wider joint

 

[Joe Malone]

I guarantee that you have will have ongoing problems with this balcony. It has been poorly specified and poorly finished. As previously pointed out, you should never use EPDM on a balcony walkway and if you do then it needs promenade tiles installing to stop wear and tear to the EPDM.