Pocster Posted February 19, 2018 Author Share Posted February 19, 2018 Right ! spoke to everyone about aerogel you can pour concrete on top - won’t compress much. But it’s u value isn’t as great as perceived ! . Roughly same u as twice the thickness of pir . I’ve read up to 6 times better - but not true .... Link to comment Share on other sites More sharing options...
Pocster Posted February 19, 2018 Author Share Posted February 19, 2018 So ! assuming my architect will allow me to drop compressive strength from 300kpa - need to find the thinnest and best u value pir available . Kingspan I guess ..... Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 19, 2018 Share Posted February 19, 2018 1 hour ago, pocster said: So ! assuming my architect will allow me to drop compressive strength from 300kpa - need to find the thinnest and best u value pir available . Kingspan I guess ..... There are only very tiny differences between different PIR insulation brands/types. They are all in the lambda range of roughly 0.021 to 0.023 W/m.K, so not enough to make a significant difference in terms of the thickness needed for a particular U value. Silica carbon aerogel tends to be just over half the lambda of PIR, so roughly half the thickness for a given U value, but it is a heck of a price. What's the specific problem with using 120mm PIR, and is there a way to overcome that in some other way? Link to comment Share on other sites More sharing options...
Pocster Posted February 19, 2018 Author Share Posted February 19, 2018 (edited) 10 minutes ago, JSHarris said: There are only very tiny differences between different PIR insulation brands/types. They are all in the lambda range of roughly 0.021 to 0.023 W/m.K, so not enough to make a significant difference in terms of the thickness needed for a particular U value. Silica carbon aerogel tends to be just over half the lambda of PIR, so roughly half the thickness for a given U value, but it is a heck of a price. What's the specific problem with using 120mm PIR, and is there a way to overcome that in some other way? Haven’t got enough depth for 120mm just spoke to se the 75mm extra pour isn’t structural in the true sense - it’s simply to stop the insulation crushing!! hmmmmm , now what are those super expensive high compression good u value blocks called ? ( about a tenner each ! ) .... foamglass ..... Edited February 19, 2018 by pocster Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 19, 2018 Share Posted February 19, 2018 So can you make the top deck out of something thin and strong, rather than concrete? How about steel decking sheets, or even structural GRP? Link to comment Share on other sites More sharing options...
Pocster Posted February 19, 2018 Author Share Posted February 19, 2018 11 minutes ago, JSHarris said: So can you make the top deck out of something thin and strong, rather than concrete? How about steel decking sheets, or even structural GRP? Maybe ! or ..... https://www.kingspan.com/gb/en-gb/products/insulation/insulation-boards/optim-r/optim-r-flooring-system kingspan super low u - looks like can have screed ontop also . Waiting a call back from Kingspan - price will be £££££ Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 19, 2018 Share Posted February 19, 2018 I reckon you could think out of the box a bit here. If you laid GRP over the insulation, ideally on ply or OSB to make it easier to lay, increased the layup thickness a bit to allow for it taking an additional load, then bonded on something like 6mm or even 8mm aluminium, or galvanised steel if you wanted more stiffness, treadplate in the area you want to bear a higher load, it might work OK. You would need high compressive strength insulation, but it would trim down your overall depth a fair bit. Link to comment Share on other sites More sharing options...
Pocster Posted February 19, 2018 Author Share Posted February 19, 2018 8 minutes ago, JSHarris said: I reckon you could think out of the box a bit here. If you laid GRP over the insulation, ideally on ply or OSB to make it easier to lay, increased the layup thickness a bit to allow for it taking an additional load, then bonded on something like 6mm or even 8mm aluminium, or galvanised steel if you wanted more stiffness, treadplate in the area you want to bear a higher load, it might work OK. You would need high compressive strength insulation, but it would trim down your overall depth a fair bit. Yeah ; it’s all possible . This would need to be designed though . Se did say that the rebar needs 35mm cover to stop corrosion - so galvanised steel could be used to reduce cover . Looking at the Kingspan product does seem to take a loading of 160kpa . They must have an se themselves that would ‘design’ something that’s meets my criteria - at a cost of course !!! cheers Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 19, 2018 Share Posted February 19, 2018 Presumably you only need the added strength over the actual area where you plan to park cars, is that right? I am pretty sure you could get a steel fabricator with experience of making things like vehicle trailers or the like to come up with parking area fabrication that would be thin and spread the load. It's dead easy to do the bearing load calcs, literally a few minutes work, so it may well be worth looking at to reduce the thickness. I'm not convinced that concrete as a basically non-structural deck is the best choice, given that it needs to be thick in order to provide the necessary thickness and provide the minimum cover over the reinforcement fabric, which in this case isn't adding any significant strength (it's in the middle, so doesn't see any bending loads at all) but seems to be there as an anti-crack measure. Link to comment Share on other sites More sharing options...
Pocster Posted February 19, 2018 Author Share Posted February 19, 2018 (edited) 1 hour ago, JSHarris said: Presumably you only need the added strength over the actual area where you plan to park cars, is that right? I am pretty sure you could get a steel fabricator with experience of making things like vehicle trailers or the like to come up with parking area fabrication that would be thin and spread the load. It's dead easy to do the bearing load calcs, literally a few minutes work, so it may well be worth looking at to reduce the thickness. I'm not convinced that concrete as a basically non-structural deck is the best choice, given that it needs to be thick in order to provide the necessary thickness and provide the minimum cover over the reinforcement fabric, which in this case isn't adding any significant strength (it's in the middle, so doesn't see any bending loads at all) but seems to be there as an anti-crack measure. Quite possibly a steel inner frame ( yes parking is just the middle section ) who knows what’s right ? just following se and architect as best as possible . cheers Edited February 19, 2018 by pocster Link to comment Share on other sites More sharing options...
mvincentd Posted February 19, 2018 Share Posted February 19, 2018 In your makeup what do the clippings, sand, driveway blocks bring to the party apart from an aesthetic (I assume) at the cost of what....70mm or more? Couldn’t you ‘stamp’ the concrete when it gets poured, with a block pattern, and add a dry shake dye to the concrete to get close to the look of the currently specced blocks? 1 Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 19, 2018 Share Posted February 19, 2018 16 minutes ago, pocster said: Quite possibly a steel inner frame ( yes parking is just the middle section ) who knows what’s right ? just following se and architect as beat as possible . cheers How about this as a way to get things started and weathertight: - Follow the architects spec from the ceiling level to the top of the specified insulation layer. - Add a double thickness GRP roof in the centre, standard thickness at the sides, laid on to OSB or ply, and following the CFS guidance, with the pre-moulded gutters, upstands etc around the edges and skylight aperture. - You then have a strong and watertight roof, and you can stop and have a think about the next stage, making the centre section into a parking space. This plan can get you going without closing off any future options, really, and gives you time to work through some ideas for the parking area. I can think of a handful of ways you could do this, and all would work OK on top of that roof make up, I'm sure. Link to comment Share on other sites More sharing options...
Onoff Posted February 19, 2018 Share Posted February 19, 2018 16 hours ago, SteamyTea said: So as you brake near the edge won't the car's momentum potentially "shift" the edge blocks into the GRP upstand and fairly rapidly destroy it... Link to comment Share on other sites More sharing options...
SteamyTea Posted February 19, 2018 Share Posted February 19, 2018 You can make GRP look like brick, or just about anything else. Could make the whole thing from GRP/PU. 3 minutes ago, Onoff said: "shift" the edge blocks into the GRP upstand and fairly rapidly destroy it I think the gutters are parallel to the cars, but I really have no idea. But that is detail that can be solved. Link to comment Share on other sites More sharing options...
Onoff Posted February 19, 2018 Share Posted February 19, 2018 4 minutes ago, SteamyTea said: You can make GRP look like brick, or just about anything else. Could make the whole thing from GRP/PU. I think the gutters are parallel to the cars, but I really have no idea. But that is detail that can be solved. Yeah, what if it's not just blokes who park on it? Link to comment Share on other sites More sharing options...
SteamyTea Posted February 19, 2018 Share Posted February 19, 2018 Could mould in some spikes, that should get the message across Link to comment Share on other sites More sharing options...
Pocster Posted February 19, 2018 Author Share Posted February 19, 2018 2 hours ago, mvincentd said: In your makeup what do the clippings, sand, driveway blocks bring to the party apart from an aesthetic (I assume) at the cost of what....70mm or more? Couldn’t you ‘stamp’ the concrete when it gets poured, with a block pattern, and add a dry shake dye to the concrete to get close to the look of the currently specced blocks? Yep ascetics only. SWMBO not a fan of 'stamps' (so that's a dead solution). Could use patio pavers ; 30mm or so?; grabs back another 20mm. U value the issue really; looking into Kingspan vacuum insulation; U value incredible! Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 19, 2018 Share Posted February 19, 2018 Vacuum panels are great, they are what keeps the heat in so well on the Sunamp, but they cannot be cut, so have to be made to the size you need. They also need very careful handling so that they don't get punctured, as they lose most of they insulating qualities if they do, so you would need some means of blinding the top of the reinforced concrete roof in order to provide a dead flat and smooth surface. Link to comment Share on other sites More sharing options...
Pocster Posted February 19, 2018 Author Share Posted February 19, 2018 25 minutes ago, JSHarris said: Vacuum panels are great, they are what keeps the heat in so well on the Sunamp, but they cannot be cut, so have to be made to the size you need. They also need very careful handling so that they don't get punctured, as they lose most of they insulating qualities if they do, so you would need some means of blinding the top of the reinforced concrete roof in order to provide a dead flat and smooth surface. Yes ! They sound great and expensive! i am still waiting on Kingspan to call me back - must be a way to cover them safely with screed / concrete ... Link to comment Share on other sites More sharing options...
Pocster Posted February 19, 2018 Author Share Posted February 19, 2018 (edited) https://www.kingspan.com/gb/en-gb/products/insulation/insulation-boards/optim-r-e-roofing-system hey @JSHarris ! Vac in pir ? kpa 150 ! I’m really hoping my architect looks into this ... Edited February 19, 2018 by pocster Link to comment Share on other sites More sharing options...
Onoff Posted February 19, 2018 Share Posted February 19, 2018 It's pretty normal on all the roofs I work on to have a concrete upstand around the perimeter that's homogenous to the slab. e.g. - metal decking - reinforced concrete laid to falls - asphalt - decoupling membrane - blue board insulation - fabric barrier - council slabs and / or pebbles Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 19, 2018 Share Posted February 19, 2018 15 minutes ago, Onoff said: It's pretty normal on all the roofs I work on to have a concrete upstand around the perimeter that's homogenous to the slab. e.g. - metal decking - reinforced concrete laid to falls - asphalt - decoupling membrane - blue board insulation - fabric barrier - council slabs and / or pebbles The snag is this roof has the reinforced concrete on the warm side, with the insulation on top, so adding an integral upstand would be a massive thermal bridge around the edge. Link to comment Share on other sites More sharing options...
Russell griffiths Posted February 19, 2018 Share Posted February 19, 2018 Why not do away with the pavers and tile it with an external tile, or if you don’t like stamped concrete have exposed aggregate concrete as the finish, if you like different. Also can the waterproof layer go under the insulation, so clean off the slab you have, waterproof with a liquid membrane one of the new fancy ones with all the fibres in, then a load bearing xps sheet then your finished concrete. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 19, 2018 Share Posted February 19, 2018 43 minutes ago, pocster said: https://www.kingspan.com/gb/en-gb/products/insulation/insulation-boards/optim-r-e-roofing-system hey @JSHarris ! Vac in pir ? kpa 150 ! I’m really hoping my architect looks into this ... That looks pretty much ideal, as the encapsulating PIR protects the vacuum panel, making it a lot easier to use. 1 minute ago, Russell griffiths said: Why not do away with the pavers and tile it with an external tile, or if you don’t like stamped concrete have exposed aggregate concrete as the finish, if you like different. Also can the waterproof layer go under the insulation, so clean off the slab you have, waterproof with a liquid membrane one of the new fancy ones with all the fibres in, then a load bearing xps sheet then your finished concrete. Not ideal, as the water will then bypass the insulation, and ideally you don't want the insulation to allow cold water to flow down to the warm concrete below, through the inevitable gaps at the joints. Link to comment Share on other sites More sharing options...
SteamyTea Posted February 19, 2018 Share Posted February 19, 2018 (edited) 48 minutes ago, pocster said: hey @JSHarris ! Vac in pir ? kpa 150 ! I’m really hoping my architect looks into this ... Can you park a 2 tonne car on it, repeatedly. 150 kpa is about 22 lb to the square inch isn't it. Edited February 19, 2018 by SteamyTea Link to comment Share on other sites More sharing options...
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