steveoelliott Posted May 1, 2021 Share Posted May 1, 2021 (edited) Hi, Having recently had a defective flat roof replaced... per another post. I've noticed an issue with pooling water. In fairness the old roof suffered with it to some extent but less so as the outlet was made up of the membrane material. The new outlet is a single piece welded to the PVC and sits ever so slightly higher. Effectively there is a small step up to the outlet which is far from ideal. I mentioned it to the roofer and he explained that the membrane would be unaffected by this and in fact could take being soaked throughout it's life and not effect the guarantee. The details on IKO Polymeric's own site second the fact the membrane can withstand pooling. It was my understanding however that as a rule standing water should be gone within 48 hours of the last rain event... We had some heavy rain overnight Tuesday and early into Wednesday. I've attached some pictures below with a timeline of the pooling. Wednesday 5 hours after rain: Wednesday 13 hours after rain: Friday 53 hours after rain: Saturday - 83 hours after rain I am ultimately sticking down a protective fleece, paving support pads and then promenade slabs on this deck so that may or may not help to a certain extent. Should I be concerned at this pooling? What I have researched suggests not, although ideally the water should run off freely. I'm not really minded to ask folks to start pulling this apart now etc as that would mean disturbing the lead flashing and lowering the outlet in the wall. Please let me know your thoughts... Edited May 1, 2021 by steveoelliott error added twice Link to comment Share on other sites More sharing options...
nod Posted May 1, 2021 Share Posted May 1, 2021 I wouldn’t worry about it Get it decked out 1 Link to comment Share on other sites More sharing options...
Oz07 Posted May 1, 2021 Share Posted May 1, 2021 If manufacturer stands by the installation then all is well. 1 Link to comment Share on other sites More sharing options...
Marvin Posted May 1, 2021 Share Posted May 1, 2021 I would have said your roof in that area definitely doesn't leak. 1 Link to comment Share on other sites More sharing options...
steveoelliott Posted May 2, 2021 Author Share Posted May 2, 2021 Thanks folks... appreciate the feedback... Link to comment Share on other sites More sharing options...
steveoelliott Posted May 2, 2021 Author Share Posted May 2, 2021 18 hours ago, nod said: I wouldn’t worry about it Get it decked out Thanks. I’m going to after a few rain events... it’s a nightmare getting them up and laid so want to be sure. I had them off once before for a repair that didn’t work out and only found out after spending an afternoon laying them lol Link to comment Share on other sites More sharing options...
steveoelliott Posted May 5, 2021 Author Share Posted May 5, 2021 (edited) So... with all the recent rain, the roof hasn't dried out since I started this topic. With the downpours overnight, it's back to where it was. I'd estimate ~30 liters just standing. Most people I speak to say they wouldn't worry about it... I think I'll have to accept and live with it. I just like things to be right. Hopefully the protective fleece, support pads and slabs will help raise the level and shift this. I reached out directly to IKO Polymeric and they stated that their membrane can withstand even severe ponding without affecting it or the guarantee. However, they did state (as I knew) it is good practice and part of the BS standards to ensure water drains off as quickly as possible. I think this will be yet another lesson for me in hindsight... I wish I had made a point about wanting to ensure water drains off the roof quickly and not stand. Whilst the roofer recognizes the water remaining on the roof is not ideal, trying to resolve it now would involve extensive work that he believes in unnecessary. Edited May 5, 2021 by steveoelliott extra image by mistake. Link to comment Share on other sites More sharing options...
markc Posted May 5, 2021 Share Posted May 5, 2021 That is nothing to be concerned about, the parapet and walls will prevent wind from drying the water. Only worry if it gets near the top of the flashing 1 Link to comment Share on other sites More sharing options...
steveoelliott Posted May 6, 2021 Author Share Posted May 6, 2021 Thanks Mark... One of my principle concerns is with this much laying water, if you did ever get a leak it would be huge as the water doesn't get off the roof. I guess a leak is a leak and maybe I think about things to much lol Link to comment Share on other sites More sharing options...
steveoelliott Posted June 2, 2021 Author Share Posted June 2, 2021 On 05/05/2021 at 16:58, markc said: That is nothing to be concerned about, the parapet and walls will prevent wind from drying the water. Only worry if it gets near the top of the flashing Please correct me if I am wrong, but if the water came level / just over the bottom of the flashing, wouldn't that present a problem owing to the capillary action of water? Thus effectively being drawn up behind the flashing? Link to comment Share on other sites More sharing options...
markc Posted June 2, 2021 Share Posted June 2, 2021 1 hour ago, steveoelliott said: Please correct me if I am wrong, but if the water came level / just over the bottom of the flashing, wouldn't that present a problem owing to the capillary action of water? Thus effectively being drawn up behind the flashing? Couple of points to bear in mind 1) It is unlikely a flashing will be tight enough to the wall to draw water up. 2)The flashing (more upstand in this case) should be sealed to the horizontal surface and act as a tank. 1 Link to comment Share on other sites More sharing options...
steveoelliott Posted June 2, 2021 Author Share Posted June 2, 2021 Noted. Thanks Mark. 1 Link to comment Share on other sites More sharing options...
Faz Posted June 2, 2021 Share Posted June 2, 2021 It will eventually leak there because water always wins in the end but probably not in a timescale to bother you provided the roof workmanship is tidy. It would be nicer to have the fall right but, to be honest, I would take a view on it personally. 1 Link to comment Share on other sites More sharing options...
Big Jimbo Posted June 2, 2021 Share Posted June 2, 2021 The thing that i would not be happy with is that tiny water outlet. 1 Link to comment Share on other sites More sharing options...
steveoelliott Posted June 3, 2021 Author Share Posted June 3, 2021 (edited) 9 hours ago, Big Jimbo said: The thing that i would not be happy with is that tiny water outlet. In fairness the outlet is a standard size outlet and if the fall was correct would be more than ample to get the water off the roof... the problem I have is ponding water due to there being a step up to the outlet. I wish I had specified to the roofer that I wanted the falls checked before the new membrane was laid. I am at the point where if I do have more issues with this roof terrace in future, I’ll just get a firm in to extend the small bedroom over it and be done with it ; of having a proper roof on top. Would be a shame to lose the terrace though but we’ve never really had it since we moved in due to problems. Edited June 3, 2021 by steveoelliott Link to comment Share on other sites More sharing options...
Faz Posted June 4, 2021 Share Posted June 4, 2021 How are you laying the slabs - will it be enough to displace the water to a level above the outlet height? Either way, if the workmanship was ok, I would be surprised if you were to see a problem in a medium term time frame - 15 -20 years or so. 1 Link to comment Share on other sites More sharing options...
Mr Punter Posted June 4, 2021 Share Posted June 4, 2021 22 minutes ago, Faz said: How are you laying the slabs He is using pedestals 1 Link to comment Share on other sites More sharing options...
Faz Posted June 4, 2021 Share Posted June 4, 2021 Ahh - not much help then. 1 Link to comment Share on other sites More sharing options...
steveoelliott Posted August 6, 2021 Author Share Posted August 6, 2021 Finally decked out... Now after the rain we had, you can see the water between the gaps in the promenade slabs but decked out it doesn't look horrendous at least. I'm a little concerned about the water freezing during winter months and whether that will present any issues. I also noticed some hairline cracks in the grout between a couple of the copings that I will seek to get addressed. I suspect this is due to expansion / contraction but a flexible grout was used. There is a DPC under the copings but it makes sense to correct hairline cracks if I know they are there. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now