Joint in single ply facing up fall

[Moonshine]

We had our single ply installed last week and been up there a few times and just noticed a few of the welded joints in the single ply are facing up the fall as below.

 

 

I havent raised this with the roofer yet but to me these joints should be facing down the fall to take the risk of failure in the the joint

I have asked the question to the technical department of the single ply manufacturer.

What are peoples thoughts?

[Russdl]

I’ve no idea how robust those seams are, but it has to be wrong for the points you’ve raised? Hopefully an expert will be along soon to confirm or dispel your concerns. 

[Nickfromwales]

Nothing to worry about. These joints are pretty much bombproof when sealed as per the manufacturer’s installation instructions. 
There are instances where skylights etc have external corners / up-stands etc, and we install PV with plates which have the welded edges 4 sides around. 
Upstands also occur at the bottom of flat roof areas, so all the water hits that uphill-facing edge too with zero detriment. 
It’s all good. 
 

[Moonshine]

18 hours ago, Nickfromwales said:

Nothing to worry about. These joints are pretty much bombproof when sealed as per the manufacturer’s installation instructions. 
There are instances where skylights etc have external corners / up-stands etc, and we install PV with plates which have the welded edges 4 sides around. 
Upstands also occur at the bottom of flat roof areas, so all the water hits that uphill-facing edge too with zero detriment. 
It’s all good. 

 

Thanks Nick, i have also heard back from IKO Polymeric and they say the same that the direction doesnt matter.

[Nickfromwales]

Yup. They’re basically good enough to be nigh-on constantly submerged, as is the case on a lot of flat roofs after rainfall.

👍

[steveoelliott]

22 hours ago, Nickfromwales said:

Yup. They’re basically good enough to be nigh-on constantly submerged, as is the case on a lot of flat roofs after rainfall.

👍

 

I can attest to this having had an IKO Polymeric flat roof fitted with an outlet that sits a few mm higher than the membrane. I am not happy with the ponding water but have been told by the roofer and others that this does not present a problem. However, for me having ~40 liters of water on a roof that sits there for days is a disaster waiting to happen. Some say I should leave well alone as it isn't leaking but I am planning to have the outlet lowered and membrane re-sealed etc.

 

 

Edited July 28, 2022 by steveoelliott

[Nickfromwales]

8 hours ago, steveoelliott said:

Some say I should leave well alone as it isn't leaking but I am planning to have the outlet lowered and membrane re-sealed etc.

 

Leave well alone, you’ll make it worse not better. A disaster it is not, and all it requires is your absence   
Get down off your roof and go to the pub. That’s an order!!

[steveoelliott]

39 minutes ago, Nickfromwales said:

 

Leave well alone, you’ll make it worse not better. A disaster it is not, and all it requires is your absence   
Get down off your roof and go to the pub. That’s an order!!

 

You aren't the first person to say that Nick but as it holds ~40 liters of water, it just concerns me that should it ever spring a leak it will be catastrophic and not just a few marks on the ceiling below. It's also irritating as whilst I do have slabs over the top if it now, in the winter or after it has rained you can see the water under the slabs and it even saturates the ones in the corner. Then of course it freezes.

 

If done correctly and carefully I would hope to make the situation better with water draining off as it should. The issue is the outlet needs lowering through the parapet wall; it steps up to it. I do understand though that I could make something that is presently watertight, not watertight by disturbing things.

[Moonshine]

11 hours ago, steveoelliott said:

 

I can attest to this having had an IKO Polymeric flat roof fitted with an outlet that sits a few mm higher than the membrane. I am not happy with the ponding water but have been told by the roofer and others that this does not present a problem. However, for me having ~40 liters of water on a roof that sits there for days is a disaster waiting to happen. Some say I should leave well alone as it isn't leaking but I am planning to have the outlet lowered and membrane re-sealed etc.

 

 

 

To be honest this amount of water would make me really nervous, and hope that nothing bad happens with it

[Nickfromwales]

1 hour ago, steveoelliott said:

 

You aren't the first person to say that Nick but as it holds ~40 liters of water, it just concerns me that should it ever spring a leak it will be catastrophic and not just a few marks on the ceiling below. It's also irritating as whilst I do have slabs over the top if it now, in the winter or after it has rained you can see the water under the slabs and it even saturates the ones in the corner. Then of course it freezes.

 

If done correctly and carefully I would hope to make the situation better with water draining off as it should. The issue is the outlet needs lowering through the parapet wall; it steps up to it. I do understand though that I could make something that is presently watertight, not watertight by disturbing things.

You will always have a standing seam there, regardless of which layer is down first / second etc. The OSB is the base layer, then one section of membrane one level, and the outlet fold another.....and they must overlay each other which creates the 'dam'. When a roof is virtually flat there's zero you can do to make this immaculate.

[Nickfromwales]

12 minutes ago, Moonshine said:

 

To be honest this amount of water would make me really nervous, and hope that nothing bad happens with it

It's a roof! Do you worry whilst it's pi55ing down with torrential rain for 24 hours? Nope. You turn the TV on and have a nice cup of tea.

Time for a day off people!

 

[Onoff]

That'd really bug me especially when it goes stagnant and becomes a mozzie breeding ground.

 

Tip a few gallons of Desmopol over the roof and it'll fill up the depression...maybe

 

😂

[steveoelliott]

3 hours ago, Onoff said:

That'd really bug me especially when it goes stagnant and becomes a mozzie breeding ground.

 

Tip a few gallons of Desmopol over the roof and it'll fill up the depression...maybe

 

😂

It bugs me immensely hence my intention to get it remedied...

[TonyT]

50 minutes ago, steveoelliott said:

It bugs me immensely hence my intention to get it remedied...

I can fully understand that.

it would annoy me every time i saw the pool of water

[steveoelliott]

Well... I don't suppose anybody knows a good flat roofer in the Northamptonshire area do they?

[Simplysimon]

if it annoys you that much, contact adhesive stick another layer of rubber over the area to build it up

[Nickfromwales]

13 minutes ago, Simplysimon said:

if it annoys you that much, contact adhesive stick another layer of rubber over the area to build it up

Exactly what I suggested via PM , categorically avoiding making any high points any higher.

[steveoelliott]

10 hours ago, Simplysimon said:

if it annoys you that much, contact adhesive stick another layer of rubber over the area to build it up

The issue is the outlet being higher than the membrane. The falls on the membrane look to be good.

[Tom]

On 28/07/2022 at 10:24, steveoelliott said:

 

I can attest to this having had an IKO Polymeric flat roof fitted with an outlet that sits a few mm higher than the membrane.

 

Call me mental, but if the outlet is only a few mm higher could you try putting a piece of wicking material up and over the outlet? This would help to empty the pooled water quicker than evaporation alone. Probably.

[Big Jimbo]

Leave it alone. Lapped the wrong way is not a problem. A bit of water pooling might be unsightly, but not a problem.

[Onoff]

How deep is the water?

 

Lay a big piece of artificial grass up there! 😂

[steveoelliott]

On 30/07/2022 at 12:46, Onoff said:

How deep is the water?

 

Lay a big piece of artificial grass up there! 😂

I do have slabs on pedestals. It hides it for the most part but it bugs me. Based on what folks have said though it isn’t really a problem but a cosmetic annoyance.

[Onoff]

That will possibly get icy too where it's damp? Do you have a handrail or glass screen there that I'm missing?

 

Or is it not used?

[steveoelliott]

3 hours ago, Onoff said:

That will possibly get icy too where it's damp? Do you have a handrail or glass screen there that I'm missing?

 

Or is it not used?

There was an iron railing previously but we are getting a new balustrade eventually. I trust myself not to hurl myself off it but I wouldn’t take anybody up / host on it.

 

I just want to get it sorted / decide I’m going to live with it before getting it made / installed.

[Nickfromwales]

Just raise the slabs on the pedestals and leave alone. Unless you can get the best roofer in the country to pul that outlet apart and redo it, I’d not open that can of worms tbh.