rovex Posted May 23, 2012 Share Posted May 23, 2012 Although I am struggling to build my new layout and dop all the DIY in the house (why am I the only one doing the DIY - buts that another question), I have finaklly got the electric supply down to the shed. The shed is quite large as this link will show (http://www.rmweb.co.uk/community/index.php?/blog/191/entry-6699-a-home-for-brackhampton/). I've insulated the walls but not the roof (don't ask me why) but the hot summer days has revealed a problem which I suppose I should really have expected and that is that during the day the interior of the shed gets really warm. I am worried that this will cause the track to warp as well as damaging the models etc. I am wondering if anyone has any thoughts on how this can be managed. My initial thoughts are some kind of blanking out of the windows. I don't want to block them up entirely but I wonder if some coating on the inside - paper or paint might be the answer. I know in Victorian times gardeners whitewashed their greenhouse windows to stop them overheating, but its not as if you can by whitewash these days. Any suggestions gratefully received. regards Link to post Share on other sites More sharing options...
Jenny Emily Posted May 23, 2012 Share Posted May 23, 2012 Whitewashing the roof to reflect heat may be more effective. Try staple gunning baking foil to the inside of the roof to reflect heat too. Link to post Share on other sites More sharing options...
Isambard Kingdom Brunel Posted May 23, 2012 Share Posted May 23, 2012 Hi I have extreme shed envy!! Mine is only 10ft x 8ft, unfortunately the model I am building will be 16ft long Mine has "lagged" walls and roof, 1" polystyrene sheet covered with 6mm ply The floor has underlay and laminate flooring (left over from a DIY project, I was never that good at maths) I fitted lift up shutters on the inside to cover the windows, (to stop prying eyes) but find I never lift them. Mine does not get that warm in the summer, maybe because of the lined roof? In the winter I have a 800watt greenhouse heater which actually keeps it quite cosy. My thought is to get another the same as I have and bolt the two together, or start again and build one from scratch Link to post Share on other sites More sharing options...
RMweb Premium t-b-g Posted May 23, 2012 RMweb Premium Share Posted May 23, 2012 I pondered long and hard before putting up a shed in my garden. Approximately the same size (20' x 14') it has no windows, which helps security and stops sunlight warming up the interior and fading any modelling papers/watercolours etc. It also has 2" insulation in the walls, roof and floor (silver covered stuff, trade name "Reticel" or suchlike but I can't see it now to check!). I have been in there all day today and it got a little warm around 5pm, especially under anglepoise lamps with a soldering iron on so I opened the door for a while and it soon cooled down. I find the temperature is very even throught the day and the year, only requiring a very small amount of heating on the coldest winter days. A 1kw fan for half an hour usually does enough to warm it up and lamps, soldering irons and body heat are enough to keep it comfortable after that. Link to post Share on other sites More sharing options...
chrisf Posted May 23, 2012 Share Posted May 23, 2012 The shed where Tim and I work on assorted layouts used to be unbearably hot in the summer. I would find it necessary to mop my brow with a towel at frequent intervals. Over the winter the owner insulated the inside of the roof and you would not know that it was the same shed: it is now pleasantly cool in the warm weather that we have had so far this year. You are now going to ask me what material was used. I'm afraid I do not know but I will ask the owner when next we meet. Chris Link to post Share on other sites More sharing options...
RMweb Premium newbryford Posted May 23, 2012 RMweb Premium Share Posted May 23, 2012 . I am worried that this will cause the track to warp as well as damaging the models etc. Dry heat shouldn't be a major problem unless there is damp about - make sure you use good quality timber. Lay the track on a warm day as it's already "pre-expanded". Cheers, Mick Link to post Share on other sites More sharing options...
HLT 0109 Posted May 23, 2012 Share Posted May 23, 2012 Rovex, I am sure the main problem is the uninsulated roof. I can recommend 2" thick Celotex with aluminium foil on both sides. It is very light weight so no need to worry about straining the roof. I used it in my loft and have painted it white. Might be best to stick it to the roof battens rather than trying to use nails or screws. Harold. Link to post Share on other sites More sharing options...
RMweb Gold colin penfold Posted May 23, 2012 RMweb Gold Share Posted May 23, 2012 There are portable aircon units that can be set to cut in at a given temperature on a thermostat.Some also have dehumidifiers built in which would prevent damp. Example here http://www.amazon.co.uk/DeLonghi-PAC-A95-Portable-Conditioner/dp/B0025VKW64/ref=sr_1_19?s=kitchen&ie=UTF8&qid=1337808790&sr=1-19 You could also take a leaf from gardeners book and use a thermostatic vent opener as used on greenhouse roof vents. You could fit it to your existing window or pop in a roof vent and fit it to that. Man has to be comfy in his shed ) Link to post Share on other sites More sharing options...
trisonic Posted May 23, 2012 Share Posted May 23, 2012 If you seal it up entirely you'll get other problems. Cannot you get a small A/C unit that fits into a window - it will also dehumidify down to about 45% at 70f which is ideal. If you think it too expensive ask your self what your hobby is worth to you (and the stock). Best, Pete. Link to post Share on other sites More sharing options...
kandc_au Posted May 23, 2012 Share Posted May 23, 2012 Rovex, The only thing I would be worried about is trackwork warping. That said, I am talking from experience of High 30's -mid 40's The models will cope quite OK. Do you have those roof vents over there? They spin to extract hot air from buildings! If so, fit one or two o the roof with a slide cover o n the inside for the winter. Khris Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted May 23, 2012 RMweb Gold Share Posted May 23, 2012 My previous reply seems to have vanished into the ether but the message is simple - insulate the roof (and cover the windows if the face anything like south). The last shed i insulated used all sorts of stuff from expanded polystyrene sheet, packaging from the same material, and lots of corrugated cardboard saved from computer boxes at work. All held in place by odd remnants of saved ply and cheap hardboard but all the roof sections provided with an air flow. The effect inside the shed was remarakable and it became perfectly habitable in even the most extreme hot weather (although admittedly some trees to the south did add shade as well). Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted May 23, 2012 RMweb Premium Share Posted May 23, 2012 This is typical of what you need, very common in Australia, which has a worse problem with heat. http://www.twista.com.au/How-Roof-Vents-Work/ They just run with the excess heat driving them - no power required. I'd still insulate the roof of your shed. Kevin Martin Link to post Share on other sites More sharing options...
Bruciethefish Posted May 23, 2012 Share Posted May 23, 2012 A bit of 'cross pollination' here from the tropical fish world, where a lot of us build fish-houses.. You should certainly insulate the roof;- I'd assume it's felted, & will be absorbing heat from the sun all day.. 'Celotex' or 'Kingspan' are generally agreed to be the most efficient insulators, & sheets can be trapped between battens, then covered over with ply or plasterboard. It might also pay you to obtain a thermostatic switch, & link this to an extractor fan mounted in the eaves, so the hottest air is drawn out when a comfortable temperature is exceeded. You can also get a spring-loaded flap to seal the fan when the weather is cold.. Link to post Share on other sites More sharing options...
rovex Posted May 23, 2012 Author Share Posted May 23, 2012 Hi guys thanks for all the suggestions. I had intended to insulate the roof when I first bought the shed but since erection the centre roof support has sagged - The shed company did say I was building to the extremes of what they recommend. I have inserted a 4" square timber support to straighten it out - However I think that I will insulate it with lightweight materials. The walls were done with 9 mm ply and loft insulation - not ideal I know I was trying to save money at the time and it was cheaper than the foam. The walls and floor are already insulated so that should be OK. I think I might also paint the roof - I have some masonry paint left over from when we painted the house - its magnolia but so what I won't be looking at it. Finally I think I am going to have to cover the windows, I'm not particularly worried about security as their is no rear access to the garden except over the neighbours six ft fences, so I think I'll go for some paper or similar just to diffuse the light coming in so nothing is sitting in direct sunlight. Thanks again everyone Link to post Share on other sites More sharing options...
RMweb Gold PaulRhB Posted May 24, 2012 RMweb Gold Share Posted May 24, 2012 When I helped my father rebuild his layout we blocked the windows with hardboard screwed to the frame, which would take seconds to remove, and that made a huge difference. The ceiling was already insulated and he had had track warp before but none in the last 5 years since we blanked the windows. We also bought a thermostatic sensor switch and linked it to a fan with slats that blow open when it switches on but we found we only needed it when there were three in the shed to circulate air so it didn't get stuffy as it had to be set quite low to come on as the insulation and window blocking were so effective. We put the grille right up near the peak of the roof so it could suck out the hottest air and it's protected by the eaves. Naturally it also means the shed is much more snug in winter too Link to post Share on other sites More sharing options...
trisonic Posted May 24, 2012 Share Posted May 24, 2012 Yes. Ventilation is important. You cannot just seal everything up because of a build up of fumes - it's surprising what out gases even from insulation... Edit: Incl. water vapour from breathing......if you do have an extractor fan you need the capability of having somewhere to let in an adequate amount of fresh air otherwise the fan just stalls. Best, Pete. Link to post Share on other sites More sharing options...
AndrewC Posted May 24, 2012 Share Posted May 24, 2012 As others have said, insulate the roof. Its the largest surface area of the shed and its also where most of the direct sunlight hits. I went cheap with 50mm polystyrene but it makes a real difference. Celotex or similar is a good option as well. You also need exterior vents. I simply use a bathroom vent cut into one of the walls. Link to post Share on other sites More sharing options...
Talltim Posted May 24, 2012 Share Posted May 24, 2012 I thought this thread was going to be about 66s Link to post Share on other sites More sharing options...
RMweb Gold chris p bacon Posted May 24, 2012 RMweb Gold Share Posted May 24, 2012 The one thing that will make all the difference is insulation, there are various products but the best are Celotex/Kingspan for a solid board and you will need a minimum of 50mm, this can be stuck to the underside of the roof with gripfill and then cross battened. The other product is "space blanket" this is a foil covered blanket approx 40mm thick which can be stapled to the rafters (assuming you can do this every 400-600mm), both need to be taped at joins to seal, anything other than this is a waste of time and money. Correct insulation will keep heat in on a cold day and out on a hot one. You will need some trickle ventilation to keep a constant pleasant atmosphere but I would not use any kind of force ventilation (unless you intend to spray a lot) as that will mean the shed environment going through large changes in air condition, it is better to insulate, insulate, insulate and start off with a stable comfortable room before thinking of anything else. I wouldn't waste my time painting the shed roof with paint or anything else unless it is to add to the waterproofing, it will not make one bit of difference to the interior, you need to stop the heat getting in rather than trying to reflect it. The felt that is manufactured for sheds etc is designed to resist extremes of temp, by painting you could affect the longevity of the product. If you are unable to insulate the inside you could try putting it on top of the roof, this is what we call "Warm Roof" there is a solid foam product that is stuck down with hot tar and then topped with 2 layers of felt, you would need to extend the fascia to cover it, but this would be more expensive. Nice shed Link to post Share on other sites More sharing options...
RMweb Gold pirouets Posted May 24, 2012 RMweb Gold Share Posted May 24, 2012 May want to have a look at this from Nigel Burkins Blog. I am thinking of using this myself as part of the insulation for my shed. Its a strange magical liquid call Nansulate. Further up the blog there is another entry abouts its performance in the winter. http://nigelburkin.wordpress.com/page/17/ Link to post Share on other sites More sharing options...
RMweb Gold chris p bacon Posted May 24, 2012 RMweb Gold Share Posted May 24, 2012 May want to have a look at this from Nigel Burkins Blog. I am thinking of using this myself as part of the insulation for my shed. Its a strange magical liquid call Nansulate. Further up the blog there is another entry abouts its performance in the winter. http://nigelburkin.w...ss.com/page/17/ Seen this before, It has been on the market in the USA for about7-8 years, it is one of those products that makes great claims but doesn't seem able to back them up, it uses Nigels blog as a case study but without any long term analysys, just repeating his text about their claims. It could well be a good product if used in the correct place and on a suitable surface, but it relies upon creating a sealed surface to reflect heat but timber by it's very nature will move/split/warp and cannot provide that surface. The last time I looked at it, it had no U value and had not been approved by Building Control for use as there is no tested data to prove its claims. It's a nice idea but when has any thing of benefit been easy to do. Link to post Share on other sites More sharing options...
RMweb Gold pirouets Posted May 24, 2012 RMweb Gold Share Posted May 24, 2012 Nigel does have a blog entry about its performance later on as he also had ground source heat pump installed so talked about the combination of the 2 and the savings he had made. His follow up is here - http://nigelburkin.wordpress.com/page/10/ Key for me is that this is a personal view rather than the companies view. I am still digging around the interwebby thing to find more data. Link to post Share on other sites More sharing options...
RMweb Gold chris p bacon Posted May 24, 2012 RMweb Gold Share Posted May 24, 2012 Thanks for that link. Interesting reading, I note he has a ground heat pump as well, there are a couple of things that stand out for me, I have just completed and sold a 1500ft2 1 1/2 storey house with an air source heat pump (mitsubishi), they are a really good product but the house needs to have masses of insulation or they become very power hungry, there are large areas of roof as ceiling up stairs that have had to be insulated with celotex ((120mm between the rafters with 40mm below) to give an approx U value of .20, this is still not good enough for 2011 regs but the house was drawn and registered before they came in. He also has a flat roof with no insulation, it has a 250mm void which is supposed to be for ventilation, this seems rather a lot, English building regs would want 50mm airspace above the insulation, I realise that Scottish regs are sometimes different but it does seem a lot. There is nothing to stop the entire flat roof becoming a "warm roof" and keeping the airspace. Nigel also states in his blog that his house is 160m2 and his power bill should work out at £1200 for the year, (the blog was written Jan 2010), that to me very high. My house is a Victorian (1893) with 9'6" ceilings upstairs and down, has 2 extensions built in 1991 and 2001 and was rebuilt with as much insulation as I could pack into it in 2000 -2002, the floor space adds up to 2500 + ft2, my combined electric and gas for that period came out at just under £1175, and trust me when I say my wife loves the thermostat up! I think that as an added benefit the paint may be helpful, but i cannot help feeling that it just cannot do the job of say 160mm of rigid foam, as regards the original question it does not claim to keep heat out and therefore create a stable enviroment, unless I missed it.......which happens a lot nowadays ! Link to post Share on other sites More sharing options...
Rumblestripe Posted May 24, 2012 Share Posted May 24, 2012 For insulating and creating privacy for your shed might I suggest using the insulation mats that are used for campervans. They attach with suckers so can easily be removed if you want to enjoy the view, I would imagine that it would be possible to mount them more "permanently" in a shed than inside a campervan with a little creativity but they are very good at thermal and radiation shielding (so those alien control rays won't be able to operate your railway when you are at work - important consideration, I think you'll agree) http://www.campervan...ation-mats.html Link to post Share on other sites More sharing options...
RMweb Premium mezzoman253 Posted May 24, 2012 RMweb Premium Share Posted May 24, 2012 Just entered my 12x8 shed and the air temperature is 28.9C, measured near the ceiling, the lower levels are cooler. That's been in the sun since about 10am until now, about 6 hours. It's fully insulated, including the roof space which whilst keeping heat in also benefits keeping the sun heat out. The windows face the sun more or less until about 4PM this time off year. I have curtains to stop the heat coming in, but I'm considering shutters to provide extra sun blocking and security. My old 8x6 shed reach 38C in mid summer, no roof insulation, but I didn't have the layout then. Rob Link to post Share on other sites More sharing options...
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