Pocster Posted March 7, 2019 Author Share Posted March 7, 2019 1 minute ago, Ferdinand said: Different coloured dyes should do that? Problem is where an earth do I put the dye to start with ??? Link to comment Share on other sites More sharing options...
jamiehamy Posted March 7, 2019 Share Posted March 7, 2019 It *could' be moisture being drawn out through some sort of capillary action - i.e retained moisture from the slab. Don't lose heart - you will get to the bottom of this, even if it takes time and a process of elimination. I think it you had a serious water ingress issue, it would be appearing much worse than this. 1 Link to comment Share on other sites More sharing options...
Jeremy Harris Posted March 7, 2019 Share Posted March 7, 2019 2 minutes ago, Ferdinand said: Different coloured dyes should do that? Possibly, it depends on what suitable dyes are available. I've used fluorescein and OBAs (the latter is more sensitive) and the advantage of either of these is that a very tiny amount goes a long way, as they are both detectable when very highly diluted by rain. The idea is to let the rain wash the dye down into the dry part, rather than saturate the roof with enough diluted dye so as to get it to penetrate. Fluorescein has the advantage of being reasonably easy to see, although it's far better to use a UV lamp to trace it. OBAs can only be detected with UV, they aren't visible to the naked eye, but they are detectable at very low concentrations. 1 Link to comment Share on other sites More sharing options...
Pocster Posted March 7, 2019 Author Share Posted March 7, 2019 One other thought . The outside of the wall goes onto a lane . I suppose there’s a possibility rain on the lane seeping through a gap in the stone work . Checked the wall with a screwdriver no obvious gaps . Tomorrow might hose that lane side of the wall and annoy neighbors Link to comment Share on other sites More sharing options...
Pocster Posted March 7, 2019 Author Share Posted March 7, 2019 7 minutes ago, jamiehamy said: It *could' be moisture being drawn out through some sort of capillary action - i.e retained moisture from the slab. Don't lose heart - you will get to the bottom of this, even if it takes time and a process of elimination. I think it you had a serious water ingress issue, it would be appearing much worse than this. I know . its probably half a cup full if that . Its really upsetting me though because you feel like you’re failing everyday ? Link to comment Share on other sites More sharing options...
Pocster Posted March 7, 2019 Author Share Posted March 7, 2019 (edited) Well ! The guy who is doing the flashing said condensation 90% certain !!!!! He viewed it today Edited March 7, 2019 by pocster 1 Link to comment Share on other sites More sharing options...
Pocster Posted March 7, 2019 Author Share Posted March 7, 2019 (edited) RIGHT! Here is his logic which backed mine up! When it rains the walls down below do get damp - I haven't installed the dimpled membrane and drainage channel around the perimeter yet. So water is effectively in there. Evaporates and hits the ceiling but also the plastic sheet over the walk on sky lights ( plastic sheet is wet on the inside! ). Drips back to floor or tracks along any deviations in the concrete ceiling. As water is never actually removed (until drain, MVHR etc. are in) the cycle just repeats I've got the actual roofer guy coming to look tomorrow so I hope his logic backs this up! Edited March 7, 2019 by pocster 1 Link to comment Share on other sites More sharing options...
Pocster Posted March 7, 2019 Author Share Posted March 7, 2019 Thanks for the likes @jamiehamy ; just want it to be factual! He also agreed my 'logic' of sticking a piece of PIR over a 'leak' was sensible. As *in theory* tomorrow there should be no track marks under it as the moisture hit the PIR and not the ceiling.... Link to comment Share on other sites More sharing options...
Pocster Posted March 8, 2019 Author Share Posted March 8, 2019 Before and after removal of PIR Not a good test though I think Roofer arriving soon Think I might stick PIR in the upstand . Then if condensation will run down PIR and not track across ceiling Link to comment Share on other sites More sharing options...
Pocster Posted March 8, 2019 Author Share Posted March 8, 2019 Took plastic sheet off hole . You would expect the top of the stand ( where felt lips over timber ) to be dry . Not though . Does suggest condensation on the sheet dripping onto felt Link to comment Share on other sites More sharing options...
jamiehamy Posted March 8, 2019 Share Posted March 8, 2019 So, if we go with the condensation theory, which is valid , then you need to put a sheet over PIR over the light on the outside - completely covering it. Then put the DPM OVER that and lap down the sides to the ground outside. You need to do two things here 1 - Stop ingress from outside. It's got to be done properly, hence why you need to make sure the light covering goes right over the edges and there is a clear lap downwards. 2 - Reduce condensation likelihood - in your case, the roofer if thinking it's condensing on the DPM and then tracking down - so you need the PIR over the whole of the opening. However, I would sound a note of caution - I have an underground garage made of concrete. I get terrible condensation on the ceiling(which isn't insulated yet) depending on what the weather does (it's fully enclosed inside). When condensation forms, it's uniform across the whole ceiling. In your case, if you can condensation you would see it everywhere across the ceiling. It would be seriously damp. However, you will sort that as thing progress, the PIR should hopefully stop condensation in that area to let you assess if it was gathering and running down the opening. Cut that slit across the crack - one side should then dry up and help you move - literally! - in the right direction. Link to comment Share on other sites More sharing options...
jamiehamy Posted March 8, 2019 Share Posted March 8, 2019 Sorry - just seem that latest pic - you do have insulation in the slab yes? In which case that explains why no condensation on ceiling elsewhere which is good. You def need to get the covering of the opening right as it might be making things worse. I'll draw up what I mean. Link to comment Share on other sites More sharing options...
jamiehamy Posted March 8, 2019 Share Posted March 8, 2019 This is what I would do. Almost creating your skylight. This method will ensure no external ingress from the opening and minimise condensation formation. 1 Link to comment Share on other sites More sharing options...
Pocster Posted March 8, 2019 Author Share Posted March 8, 2019 Just hosed the other side of the wall . No difference to tracking Link to comment Share on other sites More sharing options...
Pocster Posted March 8, 2019 Author Share Posted March 8, 2019 Funnily enough I have seen in the past the entire ceiling covered in droplets . Should of taken a photo . The weather and air flow especially below ground must play some part in all of this . Constructed a ‘cover’ as just suggest . Just waiting for roofer to view before I install . Link to comment Share on other sites More sharing options...
Pocster Posted March 8, 2019 Author Share Posted March 8, 2019 (edited) Roofers been He said if the building was above ground he’d be 90% sure it was condensation. He said to water proof ( I assume tank ) the cracks at the corners . Then if still moisture in the same place must be condensation..... The other thing of note is if a ‘leak’ you would assume worse with more rain and extreme weather . Yet it’s pretty much constant . Edited March 8, 2019 by pocster Link to comment Share on other sites More sharing options...
Onoff Posted March 8, 2019 Share Posted March 8, 2019 Aren't dungeons meant to be damp? 1 Link to comment Share on other sites More sharing options...
Pocster Posted March 9, 2019 Author Share Posted March 9, 2019 Well . Today looks pretty much the same even with the new cover and angle grinder marks . Doesn’t seem as wet though . Can see my breathe down here but ONLY in the front bit where those 2 skylights are that ‘leak’. What does any of this prove ? Link to comment Share on other sites More sharing options...
Big Jimbo Posted March 9, 2019 Share Posted March 9, 2019 Just wanted to say, I feel for you. What a pain in the butt. These things can be so frustrating. If you could figure out what is happening you would undoubtably be able to solve it. 1 Link to comment Share on other sites More sharing options...
Pocster Posted March 9, 2019 Author Share Posted March 9, 2019 I think Monday I might angle grind those slots wider and deeper . If it appears on both sides I.e same as it is does that prove condensation?? Link to comment Share on other sites More sharing options...
Pocster Posted March 9, 2019 Author Share Posted March 9, 2019 Lifted up the new cover with PIR as @jamiehamy suggested . Felt over lapping upstand bone dry . 1 Link to comment Share on other sites More sharing options...
Pocster Posted March 9, 2019 Author Share Posted March 9, 2019 (edited) Tempted to dry it out . Then at night leave my Mac there recording the ceiling ..... My gut instinct says it won’t run from corner to edge I.e track . It will appear in ‘patches’ . But that’s just my gut feeling ! ( which I guess suggests condensation) Edited March 9, 2019 by pocster Link to comment Share on other sites More sharing options...
Mr Punter Posted March 9, 2019 Share Posted March 9, 2019 The roof is OK as will be the skylights if they are correctly installed. Once you have the placed sealed up you will be able to see if you have an issue. You need to make sure all the junctions are completed and that DPCs, DPMs, flashings, copings etc are all correctly detailed and installed. 1 Link to comment Share on other sites More sharing options...
jamiehamy Posted March 9, 2019 Share Posted March 9, 2019 11 hours ago, pocster said: I think Monday I might angle grind those slots wider and deeper . If it appears on both sides I.e same as it is does that prove condensation?? Condensation or residual moisture being drawn out through the crack. It's interesting no change with the score. Does suggest moisture permeating through. Remember concrete will still be drying (it will for a long time) so maybe that's l this is? Might be no harm in leaving it for the time being and see if it dries up of its own accord? Its no flowing and rain fall doesnt seem to directly affect. You could probably do with a break from it now! 1 Link to comment Share on other sites More sharing options...
Pocster Posted March 11, 2019 Author Share Posted March 11, 2019 Going to consider it condensation as can't find any leak any where. So will continue as is ! Link to comment Share on other sites More sharing options...
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