Barney12 Posted May 12, 2017 Share Posted May 12, 2017 Well after a week of graft by Brendan, Matt and their lads we have a slab. The weather from Tue has been appalling up here. The last two days torrential rain but they've kept going never the less. Now we we just need a break in the weather to pour the concrete. Its pencilled for Wed but all week isn't looking good according to the forecast 7 Link to comment Share on other sites More sharing options...
Bitpipe Posted May 12, 2017 Share Posted May 12, 2017 Thats the first stepped MBC slab that I've seen - did that complicate matters? Link to comment Share on other sites More sharing options...
RichS Posted May 12, 2017 Share Posted May 12, 2017 Looking good, hope you get some decent weather for the pour. Are you not bothering to pressurise the underfloor pipes before you pour??. I have often thought about not bothering when I eventually reach that stage but was never sure!!! Link to comment Share on other sites More sharing options...
PeterW Posted May 12, 2017 Share Posted May 12, 2017 Just now, RichS said: Looking good, hope you get some decent weather for the pour. Are you not bothering to pressurise the underfloor pipes before you pour??. I have often thought about not bothering when I eventually reach that stage but was never sure!!! I put 4 bar in ours overnight and then dropped it to 3 bar for the pour. When it had all gone off (and stopped fluctuating from the heat ..!) I dropped to 1 bar and it's stayed there ever since just as an assurance that I don't catch the pipes coming up to the manifold. Link to comment Share on other sites More sharing options...
DavidFrancis Posted May 12, 2017 Share Posted May 12, 2017 Hope this doen't sound too doom-mongerish, but if there was an extremely strong wind before the pour, is there any chance this could all blow away? (No idea what the mesh and rebar might weigh.) Link to comment Share on other sites More sharing options...
Jeremy Harris Posted May 12, 2017 Share Posted May 12, 2017 59 minutes ago, RichS said: Looking good, hope you get some decent weather for the pour. Are you not bothering to pressurise the underfloor pipes before you pour??. I have often thought about not bothering when I eventually reach that stage but was never sure!!! We didn't bother, hasn't been a problem at all, the system has been sat at 1.5 bar for a couple of years now, and never seems to change pressure at all. given the inherent stiffness of the pipe, and the fact there are no joins in the slab, plus the fact that the pipe is fitted to the reinforcing fabric as the last job before the pour, so is not at any significant risk of damage, I'm not convinced it's worth the bother of pressurising it before the pour. We didn't have the ability to do this, anyway, as we had no water supply on site at that time, and I couldn't be bothered to make up some sort of jury rig for what seemed to me to be a near-zero risk. 34 minutes ago, DavidFrancis said: Hope this doen't sound too doom-mongerish, but if there was an extremely strong wind before the pour, is there any chance this could all blow away? (No idea what the mesh and rebar might weigh.) Not very likely, as all that steel is pretty weighty, as is the EPS itself. Link to comment Share on other sites More sharing options...
RichS Posted May 12, 2017 Share Posted May 12, 2017 @JSHarris Thanks for that reply Jeremy, I will have water on site but I didn't really fancy farting around fitting the manifold etc. when there is a very good chance of it getting damaged. Your reply has just convinced me not to bother Link to comment Share on other sites More sharing options...
jack Posted May 12, 2017 Share Posted May 12, 2017 We also didn't pressurise. The only leak we had was the poor electrician nicking one of the pipes with a screw while installing some protective steel around a floor box when our concrete overlay was being poured. Link to comment Share on other sites More sharing options...
Barney12 Posted May 12, 2017 Author Share Posted May 12, 2017 5 hours ago, Bitpipe said: Thats the first stepped MBC slab that I've seen - did that complicate matters? Yes a little. We had to cut the site on two levels, then shutter the step to allow for the hardcore (note our spec was MOT1 not clean stone as others have used) to be compacted correctly. Setting out also had to be very precise as there is very little margin for error when you have two levels and 4 90 degree angles in that step I solved that isssue (partly) by pre manufacturing the shuttering to exact measurements. Link to comment Share on other sites More sharing options...
Barney12 Posted May 12, 2017 Author Share Posted May 12, 2017 4 hours ago, DavidFrancis said: Hope this doen't sound too doom-mongerish, but if there was an extremely strong wind before the pour, is there any chance this could all blow away? (No idea what the mesh and rebar might weigh.) Not a chance. I was quite suprised quite how heavy those slabs of polystyrene are, then with the steel on top it's not going anywhere in a hurry. Link to comment Share on other sites More sharing options...
Barney12 Posted May 12, 2017 Author Share Posted May 12, 2017 Ref the pressuring of the UFH; I'm not going to bother. MBC are clear it's not required and don't ever do it as standard. That pipe is really very tough, it's appears to have a metal core if I'm not mistaken. I tried crushing an offcut with my size 10's and it was almost impossible to do without a darn good stamping!! Link to comment Share on other sites More sharing options...
Nickfromwales Posted May 13, 2017 Share Posted May 13, 2017 9 hours ago, Barney12 said: Ref the pressuring of the UFH; I'm not going to bother. MBC are clear it's not required and don't ever do it as standard. That pipe is really very tough, it's appears to have a metal core if I'm not mistaken. I tried crushing an offcut with my size 10's and it was almost impossible to do without a darn good stamping!! The 'al' in Pex-al-pex is indeed metal, aluminium to be precise. . And yes, you can dance on the stuff TBH, with damage only ever occurring from too tight a bending radius or nails / screws. If you had some atop of the rebar / mesh then stepping on it between points of suspension wouldn't go well, so just be mindful and control access to the site before your pour so no such accidents can happen. Link to comment Share on other sites More sharing options...
Barney12 Posted May 13, 2017 Author Share Posted May 13, 2017 (edited) 6 minutes ago, Nickfromwales said: The 'al' in Pex-al-pex is indeed metal, aluminium to be precise. . And yes, you can dance on the stuff TBH, with damage only ever occurring from too tight a bending radius or nails / screws. If you had some atop of the rebar / mesh then stepping on it between points of suspension wouldn't go well, so just be mindful and control access to the site before your pour so no such accidents can happen. Thanks Nick. No one up here until the pour so we should be OK. On a different note; I've just been pondering if it's worth feeding a flow and return pipe into the slab for the lower manifold? Obviously I can route it through the stud walls once they're up but any advantages to burying a 22mm pipe run in two conduits now? Edit: I should add that one advantage is that the run in the slab would be much shorter as in the stud I'll have to go up, across and down to avoid the door openings. Edited May 13, 2017 by Barney12 Link to comment Share on other sites More sharing options...
dogman Posted May 13, 2017 Share Posted May 13, 2017 Looking good, Have you put joints at slab level for those SVPs so you can connect at floor level if needed. saves digging out the slab later Link to comment Share on other sites More sharing options...
Barney12 Posted May 13, 2017 Author Share Posted May 13, 2017 2 hours ago, dogman said: Looking good, Have you put joints at slab level for those SVPs so you can connect at floor level if needed. saves digging out the slab later No! I'll add that to my list of weekend jobs! Thanks for the pointer. Link to comment Share on other sites More sharing options...
Nickfromwales Posted May 13, 2017 Share Posted May 13, 2017 2 hours ago, Barney12 said: Thanks Nick. No one up here until the pour so we should be OK. On a different note; I've just been pondering if it's worth feeding a flow and return pipe into the slab for the lower manifold? Obviously I can route it through the stud walls once they're up but any advantages to burying a 22mm pipe run in two conduits now? Edit: I should add that one advantage is that the run in the slab would be much shorter as in the stud I'll have to go up, across and down to avoid the door openings. I'd go for it. Any less work to do later is a bonus in my book . Make sure your capping / taping all these pipe ends thoroughly ? Link to comment Share on other sites More sharing options...
Nickfromwales Posted May 13, 2017 Share Posted May 13, 2017 25 minutes ago, Barney12 said: No! I'll add that to my list of weekend jobs! Thanks for the pointer. You could sleeve them with 6" off cuts too so you get a bit of movement later . Just set the sleeves down into exp foam so the concrete doesn't creep in. I had to relocate 3 SVP's in one job and that was a real bastard of a job. Foresight like this would have made things SO much easier. . Link to comment Share on other sites More sharing options...
Barney12 Posted May 16, 2017 Author Share Posted May 16, 2017 Rain is still stopping play Plus the building inspector has thrown a wobbly as they've used A393 rebar/mesh not the A252 specified by the engineer. Not sure why 2mm extra of steel thickness is really an issue If all that UFH pipe has got to come up then there will be some very unhappy Irishmen around! Link to comment Share on other sites More sharing options...
Carrerahill Posted May 16, 2017 Share Posted May 16, 2017 (edited) 11 minutes ago, Barney12 said: Rain is still stopping play Plus the building inspector has thrown a wobbly as they've used A393 rebar/mesh not the A252 specified by the engineer. Not sure why 2mm extra of steel thickness is really an issue If all that UFH pipe has got to come up then there will be some very unhappy Irishmen around! I think it would be easier jut to to get a note of comfort from the engineer and shove it in the inspectors face, some careful polite discussion with him should suffice though, which to be honest is all a nonsense given that the re-bar going in is heavier and will offer more support, not like they used A192 or something! It is just a bit over the top - like using a 6x2 instead of spec'ed 4x2! I do really wonder about the inspectors sometimes. Edited May 16, 2017 by Carrerahill Link to comment Share on other sites More sharing options...
Barney12 Posted May 16, 2017 Author Share Posted May 16, 2017 Just now, Carrerahill said: I think it would be easier jut to to get a note of comfort from the engineer and shove it in the inspectors face, some careful police discussion with him should suffice though, which to be honest is all a nonsense given that the re-bar going in is heavier and will offer more support, not like they used A192 or something! It is just a bit over the top - like using a 6x2 instead of spec'ed 4x2! I do really wonder about the inspectors sometimes. Yes. This guy is something of a jobsworth it seems. It wasn't the normal guy we've had thus far who has actually been fine. He only works three afternoons a week and turned up in an E Class Mercedes Estate! I've asked the engineer for a comfort letter for "the file". Link to comment Share on other sites More sharing options...
Barney12 Posted May 24, 2017 Author Share Posted May 24, 2017 Finally the wet weather has cleared and the guys can get on with the concrete. Today its apparently too hot. Cant win 1 Link to comment Share on other sites More sharing options...
Dudda Posted May 24, 2017 Share Posted May 24, 2017 Congratulations. Keep it damp to avoid it drying out too fast and developing surface cracks. Just a note on pressurising the underfloor heating pipes. Where it’s fixed to steel mesh with cable ties or similar it’s fine but if you’ve underfloor heating in a thin screed which is put in near the end rather than the start of the project and it’s clipped down with the plastic staples which are just pushed into insulation than it can come up with concrete pumps or wheel barrows going over it. It’s not the pipe that fails but the plastic staples that come loose in the insulation. In this case the additional weight of the water in the pipes help keep it down and stop the pipes floating to the top of a thin screed. If the pipes are full of air instead of heavier water they can float to the top of a screed. 1 Link to comment Share on other sites More sharing options...
Barney12 Posted May 24, 2017 Author Share Posted May 24, 2017 6 hours ago, Dudda said: Congratulations. Keep it damp to avoid it drying out too fast and developing surface cracks. Just a note on pressurising the underfloor heating pipes. Where it’s fixed to steel mesh with cable ties or similar it’s fine but if you’ve underfloor heating in a thin screed which is put in near the end rather than the start of the project and it’s clipped down with the plastic staples which are just pushed into insulation than it can come up with concrete pumps or wheel barrows going over it. It’s not the pipe that fails but the plastic staples that come loose in the insulation. In this case the additional weight of the water in the pipes help keep it down and stop the pipes floating to the top of a thin screed. If the pipes are full of air instead of heavier water they can float to the top of a screed. I've been watering it all late afternoon/evening after the guys went. Just did the final drenching at 9pm. Hopefully I've done enough to stop any cracking! UFH was indeed cable tied to rebar so all ok. 1 Link to comment Share on other sites More sharing options...
Barney12 Posted May 30, 2017 Author Share Posted May 30, 2017 So the frame is arriving......Slowly! Its taken them the best part of an hour to move three panels down the lane by telehandler. Its of course as standard p*ss*ng it down with rain! I think they're in for a long afternoon. Worse still I'm trapped at the flat on-site as I cant get out. No milk or food in the fridge. I've just had to resort to eating Linda McCartney Veggy Sausages as it was the ONLY thing in the freezer which I could cook from frozen YUK! Link to comment Share on other sites More sharing options...
mike2016 Posted May 30, 2017 Share Posted May 30, 2017 That will give you flashbacks in the supermarket isle in the years to come!!! Hope you added loads of brown sauce to 'em?!! Link to comment Share on other sites More sharing options...
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