Replacement EPDM flat roof - water pooling problem

[shinano]

We have just had the leaking tar flat roof over our garages replaced with the EPDM rubberbond system. The boards were also replaced at the same time.

It rained heavily on thursday and friday and 24 hours later we still have pools of water on the roof near the corners. I have attached some pictures so you can see where the water is pooling. The builder of course says that this is not a problem. Since we had the boards replaced as well as the roof I am very disappointed that there is no proper drainage or runoff of water from the roof. Note the roof is totally flat - perhaps we should have insisted on a slope being installed when the boards were replaced ?

Looking at the pictures any opinions on what if anything the builder should do about this ?

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• shinano
• 12 Feb 2011
• 1

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• shinano
• 12 Feb 2011
• 1

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• shinano
• 12 Feb 2011
• 1

 

[alittlerespect]

Hi

In hindsight the builder could have added some tapered firring pieces to the top of the joists to provide a better fall to the roof, and as we all know 'hindsight' is a wonderful attribute, just the timing is out.
However, it is also likely that the builder priced for replacing the roof coveing on a like for like basis and had not considered the need for the tapered firring pieces.

The good news! If water is ponding at least you know you don't have a leak! And it looks worse than what it really is!

Regards

 

[Mw Roofline]

I wouldn't worry about it. Put it this way it won't leak.

 

[Nige F]

As above - and your old roof had a layer of chippings which would have hidden any puddles from the day it was laid

 

[shinano]

As above - and your old roof had a layer of chippings which would have hidden any puddles from the day it was laid

The old roof was 3 layer felt with tar and chippings so this is probably true.

I note the views above that the water pooling is not a problem - I am just concerned that over time pools of water have a tendency to find ways into property (frost damage ?). Also as we paid extra to have the boards replaced should we not expect the new roof surface to be completely level/better drained ?

 

[Mw Roofline]

It's like a pond liner, if it freezes it will just 'float' on the epdm

 

[henseyroofing82]

Flat roofs, if carried out correctly can and do have water pooling on them without any problems at all, what I would be more concerned about is the open ridge ends? Where is the cement and what is is stopping the birds nesting in them or any other infestations occurring?

 

[shinano]

Flat roofs, if carried out correctly can and do have water pooling on them without any problems at all, what I would be more concerned about is the open ridge ends? Where is the cement and what is is stopping the birds nesting in them or any other infestations occurring?

Well spotted ! The work was not finished when these pictures were taken. The builder has now cemented the hip tiles into place. There is leadwork under the tiles. Photo attached now the work is complete. Plenty of water pools as it is raining heavily. I do hope the water evaporates within 48 hours or so.

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• shinano
• 15 Feb 2011
• 1

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• shinano
• 15 Feb 2011
• 1

 

[htgeng]

Look on the bright side. At least the guy didn't say "well you have your very own paddling pool now".

Realistically theres nowt you can do about it now as no way will he swallow the cost of ripping it all off and re-decking it. I would agree with points others made that he should have at least told you of the likely outcome and suggested a fall was added. Will you be recommending him to others?

 

[shinano]

After 2 days with no rain and some sun the result is some water remains in 2 patches - the rest of the water has evaporated.

I accept that nothing can be done now the work is finished but it is a lesson for homeowners - if you expect a dry well drained roof you must specify as such when you get the quote. You cannot just assume that work such as reboarding will ensure the roof drains completely.

I did email the technical department of the company that imports EPDM - they assure me that
"The 48 hrs is a good guideline with the majority of roofing membranes, as the pooling can magnify the sun’s rays, causing a rapid acceleration of the breakdown of the material. EPDM has the benefit of being completely UV and ozone stable, thus entirely unaffected in this way"

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• shinano
• 18 Feb 2011
• 1

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• shinano
• 18 Feb 2011
• 1