Swissfil Posted April 6 Share Posted April 6 Hi all, hope everyone is well? Im Phil, semi retired - well 20% at least. Few more years left to graft, but hey ho at least I've got my health ! - he says coughing...... Just moved to Portishead with my partner into our forever home. It has a single lean to garage attached which I am going to knock down and extend to make into a 7.5m x 3.5m workshop. This has always been a dream of mine which I am very lucky is now possible due to my Mum passing away last yr. I was originally going to build in cavity block with a traditional roof, but have decided to go all sips to save space, quicker build time and keep as warm as possible as this will be a car restoration hub, and also for a motorbike. We are awaiting planning as we are building to edge of our boundary. Should be with us in 2-3 weeks. I am a kitchen/bathroom designer and fitter so I am handy in terms of putting stuff together well. Whilst I have done some drawings and understand how sips fit together in terms of roof, walls, floor, it is the foundations I need help with. The garage will also have a small first floor loft as storage space (this is a dormer bungalow) but is not classed as a dwelling and has no windows, but obvs will need regs. I have done 3 drawings of possible foundation combinations, but don't know which one to go for. Not even sure if footings are right depth or width. Any help would be appreciated Pics enclosed apologies for not labelling everything - this has been done on freeform...but you'll get the general idea hopefully. I hope to do a build thread once I start in June and detail it all. Many thx in advance Phil Link to comment Share on other sites More sharing options...
SteamyTea Posted April 6 Share Posted April 6 While I appreciate it is only a workshop, thermal bridging is still important for longevity for sips, which are only OSB and PU foam, both of which absorb moisture. So in my opinion, the middle image is heading in the correct direct. I think the KORE foundation system puts the thermal break on the outside and the panels would be sitting on the fully insulated slab, but it is a while since I looked at the details. 1 Link to comment Share on other sites More sharing options...
Swissfil Posted April 6 Author Share Posted April 6 6 minutes ago, SteamyTea said: While I appreciate it is only a workshop, thermal bridging is still important for longevity for sips, which are only OSB and PU foam, both of which absorb moisture. So in my opinion, the middle image is heading in the correct direct. I think the KORE foundation system puts the thermal break on the outside and the panels would be sitting on the fully insulated slab, but it is a while since I looked at the details. Thx SteamyTea Yes that was my concern, thermal bridge issues. There will be a built in centrifugal extractor with humidistat, but even so I don't want the sips to rot out! Also when I say workshop, it does need to be dry and warm as I will be undertaking nut a bolt rebuilds of classic cars eventually. thx for your input Link to comment Share on other sites More sharing options...
saveasteading Posted April 6 Share Posted April 6 Agreed number 2. So much easier to build and also means that the slab can poured last, and in the dry. You need a stone sub base beneath the eps. Again that is a good working surface while you build it. I'd use "stick build", esp with your skills. You should line the walls internally to be fire resistant, being on the boundary. Is the neighbour OK that you will be working in their garden? 1 Link to comment Share on other sites More sharing options...
Swissfil Posted April 6 Author Share Posted April 6 2 minutes ago, saveasteading said: Agreed number 2. So much easier to build and also means that the slab can poured last, and in the dry. You need a stone sub base beneath the eps. Again that is a good working surface while you build it. I'd use "stick build", esp with your skills. You should line the walls internally to be fire resistant, being on the boundary. Is the neighbour OK that you will be working in their garden? Thx Saveasteading Slab poured last is something I hadn't considered, great plan. Stone sub is fine just didn't detail it. Walls will be lined internally with firecheck. Will also have 60 min fire door to access utility at rear. Neighbour is away abroad for 8 months of the year and the house is empty, so we haven't met him yet. Hope this won't be a problem though as we have similar interests - at least that's what I understand from the other neighbours. I very much doubt he has recd the letter from planning tbh! Thx for your input 1 Link to comment Share on other sites More sharing options...
saveasteading Posted April 6 Share Posted April 6 6 minutes ago, Swissfil said: Hope this won't be a problem 1. Don't cross the boundary with the footing of any overhangs. 2. You need to work from their garden now and for maintenance. 3. If rain lashes against the side wall does it run on their garden? 4. It needs to look good on their side. 5. Will it affect their enjoyment? Link to comment Share on other sites More sharing options...
Swissfil Posted April 6 Author Share Posted April 6 1 hour ago, saveasteading said: 1. Don't cross the boundary with the footing of any overhangs. 2. You need to work from their garden now and for maintenance. 3. If rain lashes against the side wall does it run on their garden? 4. It needs to look good on their side. 5. Will it affect their enjoyment? Won't be crossing boundary but will be right up against it. Yes I hope he will let me because it will get complicated otherwise or I'll have to loose 30/40cm from side wall which defeats the expense! Yes rain will run on to their garden/drive possibly but it is a west facing wall so very rarely. It will look good as I am cladding boundary wall in composite boards in the colour of their choice! Unlikely to affect their enjoyment I think, but time will tell. As he only lives in the country for 4 months of the year I am hoping there won't be any issues. Thx for those points Link to comment Share on other sites More sharing options...
jfb Posted April 6 Share Posted April 6 I had a similar sized sips cabin built for me by a couple of Canadian builders. It had sips as the floor as well built on concrete pillars. Very happy with it. Can’t tell you the exact build details of the floor construction. But I think it was something like metal straps concreted in to the pillars fixed to the studs between the panels. Link to comment Share on other sites More sharing options...
Swissfil Posted April 11 Author Share Posted April 11 On 06/04/2024 at 14:42, jfb said: I had a similar sized sips cabin built for me by a couple of Canadian builders. It had sips as the floor as well built on concrete pillars. Very happy with it. Can’t tell you the exact build details of the floor construction. But I think it was something like metal straps concreted in to the pillars fixed to the studs between the panels. Thx for that but can't do a sips floor as will be having too much weight on it! Link to comment Share on other sites More sharing options...
markc Posted April 11 Share Posted April 11 42 minutes ago, Swissfil said: Thx for that but can't do a sips floor as will be having too much weight on it! Why? What sort of loads are we talking? About 40 yrs ago I put one of the first sips floor houses up in Ideal Home Exibition, during the panel testing a 3mx3m panel had around 4tons in the centre and this was only supported around the edges. Point loads can be minimised with a little thought Link to comment Share on other sites More sharing options...
kandgmitchell Posted April 11 Share Posted April 11 Just a thought. That composite cladding needs to be at least Class B-s3 d2 spread of flame classification. The external wall needs 30 minutes fire resistance from both sides. Your fireline plasterboard should be ok for the inner face but the composite cladding is unlikely to allow the wall to be fire resistant from the external side. My thought is it will need a cement based board behind the cladding. You will need to check this with your SIP provider. The door off the garage just needs to be an FD30S door with a closer. Also BC may want a landing at the top of those steps that is not obstructed by the door..... Link to comment Share on other sites More sharing options...
Swissfil Posted April 11 Author Share Posted April 11 2 hours ago, markc said: Why? What sort of loads are we talking? About 40 yrs ago I put one of the first sips floor houses up in Ideal Home Exibition, during the panel testing a 3mx3m panel had around 4tons in the centre and this was only supported around the edges. Point loads can be minimised with a little thought It's going to be a garage/workshop. I need a solid slab floor. I will be using 100mm EPS under the slab. The slab will be C32/40 and appx 175mm depth. Link to comment Share on other sites More sharing options...
Swissfil Posted April 11 Author Share Posted April 11 1 hour ago, kandgmitchell said: Just a thought. That composite cladding needs to be at least Class B-s3 d2 spread of flame classification. The external wall needs 30 minutes fire resistance from both sides. Your fireline plasterboard should be ok for the inner face but the composite cladding is unlikely to allow the wall to be fire resistant from the external side. My thought is it will need a cement based board behind the cladding. You will need to check this with your SIP provider. The door off the garage just needs to be an FD30S door with a closer. Also BC may want a landing at the top of those steps that is not obstructed by the door..... Thx I will check with BC and sips provider. Link to comment Share on other sites More sharing options...
DillyDilly Posted September 30 Share Posted September 30 Looking at your drawings, do you / would you require a cavity wall at ground level, even if you fix cladding as your external skin ? Link to comment Share on other sites More sharing options...
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