RMweb Premium Pannier Tank Posted December 26, 2012 RMweb Premium Share Posted December 26, 2012 Not a problem! I'm pretty much sorted - I'm finding your dilemma far more interesting than mine ever was!!! Good luck. A bit more stressful as well I guess. I'll have to start a blog or thread at some stage and show you what I've been up to! Link to post Share on other sites More sharing options...
RMweb Premium Pannier Tank Posted December 26, 2012 RMweb Premium Share Posted December 26, 2012 I wouldn't worry too much as you have plenty of room between the underside of the joists and the groundlevel, sometimes we put a DP membrane over the ground held down with a bit of shingle, this cuts down mould growth on the wet ground, or you can spread a bit of lean mix over it. You won't stop the ground water but with a 300mm air gap it shouldn't present any problems for you, you could for a bit of extra vent put 2 more brick sized vents along the 7.5M, the more the merrier. Along with Pete you have the makings of a top notch room coming along there, look forward to seeing what happens on the inside. In the summer months I have had some toadstools grow in the soil so I am a bit concerned about mould growth etc. Maybe I should lay a polythene membrane down and add a jumbo bag or two of ballast over the top (or would I be better off putting down a wet concrete mix)? I'm just looking for peace of mind once the floor goes down. I don't want to reach retirement and have to rip it all out and put right what have I have a chance of getting right now. Link to post Share on other sites More sharing options...
RMweb Gold chris p bacon Posted December 27, 2012 RMweb Gold Share Posted December 27, 2012 In the summer months I have had some toadstools grow in the soil so I am a bit concerned about mould growth etc. Maybe I should lay a polythene membrane down and add a jumbo bag or two of ballast over the top (or would I be better off putting down a wet concrete mix)? I'm just looking for peace of mind once the floor goes down. I don't want to reach retirement and have to rip it all out and put right what have I have a chance of getting right now. That would be a "lean mix" concrete, If you are hand mixing/small mixer (rather than ready mix) concrete you would usually mix at the rate of 5:1 ( or 15 heaped shovels and a half a bag of cement) but for lean mix you can push that out to 8:1 or if you are really tight 10:1. You don't want the concrete for it's structural strength as such but to create a large slab over the membrane. With pressure treated joists, plenty of ventilation and insulation, your floor will outlast us all. For the floor covering use 18mm chipboard with 450mm centre joists, or 22mm with 600 centre, when you lay the boards use one of the epoxy gap filling glues that are made for T & G chipboard, it costs more but is well worth it, it will expand and fill any small holes to cut out any air leakage as well as tightly seal the joint against moisture ingress. Nowadays there is a product to suit all conditions so there is no need to worry......unless like me it's your modelling you worry about ! Link to post Share on other sites More sharing options...
RMweb Premium TheQ Posted December 27, 2012 RMweb Premium Share Posted December 27, 2012 If you are having a wooden floor you definately need the membrane to stop the humidity coming up through the floor. I would use sand rather than ballast, as ballast may pucture the membrane, I would get the sand from the Beeston quarry if you have some way to transport it by the ton, it's a lot cheaper! As you can guess I'm also in North Norfolk and can see the back of the sand dunes. I would definately recommend a dehumidifier due to our High humidity around here. Some flooring chipboard is relatively waterproof Resistant if it is of a bathroom grade however most hate water and will disintegate if you get a leak through the felt. as soon as you can you need to replace the felt with a something better like Coroline corrogated panels or metal sheeting or as I have done, I've fibreglassed my railway shed roof. I've found CFSnet.co.uk a good supplier for that. The Q Link to post Share on other sites More sharing options...
Pete 75C Posted December 27, 2012 Author Share Posted December 27, 2012 Almost everything that's gone into the renovation of this house has come from Drayton Stone Pits at Beeston! I had half a dozen bulk bags from CT Baker on the drive earlier this year when Shane from DSP simply walked up the path, knocked at the door and offered a better deal... Back to the structure, the lean-to has actually been built on the footprint of a structure that's been there since the house was built in 1894. The foundation just seems to keep going down forever so I have no worries about a suspended floor and the airflow problems associated with it. the only reason for rebuilding was that the longest wall was unsafe, bowing outwards by over 12 inches in a 6ft height. When I demolished the structure, it only took a gentle nudge to come down! I'll put a couple of pics of before and after to another post in this thread. As I said earlier - my only concern is the longevity of the roof. The structure is not a concern - 125mm x 50mm treated timber at 400mm centres topped with 22mm chipboard flooring panels and they are the green water-resistant type. The covering, however, is a cause for concern. I know 2 layers of heavy duty felt aren't going to outlive me. I'll keep an eye on it and maybe recover with corrugated bitumen panels in the near future. We've had a stupid amount of rain lately and everything seems ok but, yes, it is a concern. Pete. Link to post Share on other sites More sharing options...
Pete 75C Posted December 27, 2012 Author Share Posted December 27, 2012 If you can't tell which is "before" and which is "after"... very funny! Internal size is 12ft by 6ft which is ample for my needs. As it's an old house with combined drainage, I've taken the run-off from the gutter into the top of the soil stack - not perfect I know, and a proper P trap will be installed when the concrete is replaced for something a little more aesthetically pleasing. That will keep the rainwater and the vent apart. Link to post Share on other sites More sharing options...
RMweb Premium Pannier Tank Posted December 27, 2012 RMweb Premium Share Posted December 27, 2012 That would be a "lean mix" concrete With pressure treated joists, plenty of ventilation and insulation, your floor will outlast us all. For the floor covering use 18mm chipboard with 450mm centre joists, or 22mm with 600 centre, when you lay the boards use one of the epoxy gap filling glues that are made for T & G chipboard, it costs more but is well worth it, it will expand and fill any small holes to cut out any air leakage as well as tightly seal the joint against moisture ingress. That's great, now we have a good plan of action! I'll borrow / hire a small mixer and go with the lean concrete mix over a polythene membrane. Ok on using a glue / filler on the T&G Flooring, I'd not considered gluing so that's great advice! I'll try and get a picture up later to show progress so far, I'm encourage by the help you given. Link to post Share on other sites More sharing options...
Pete 75C Posted December 27, 2012 Author Share Posted December 27, 2012 Ok on using a glue / filler on the T&G Flooring, I'd not considered gluing so that's great advice! Hi David. I used something similar in the grooves when assembling the T&G roof panels and it works a treat - it fills any voids as the panels are assembled and is an extra safeguard against moisture getting into the gaps. Well worth doing. Pete. Link to post Share on other sites More sharing options...
RMweb Premium Pannier Tank Posted December 27, 2012 RMweb Premium Share Posted December 27, 2012 Hi Pete, I am really pleased that you started this thread and allowed me to ask a few questions, it has help me no end. Link to post Share on other sites More sharing options...
RMweb Gold Jonboy Posted December 27, 2012 RMweb Gold Share Posted December 27, 2012 Have you considered one of the rubber roof sheet materials instead of felt? My Dad had his garage done with them 15 years ago. It cost about 20% extra but has'nt needed any maintainence to date. If I were to install a shed or garage myself I would use it without hesitation. Link to post Share on other sites More sharing options...
RMweb Premium Pannier Tank Posted December 27, 2012 RMweb Premium Share Posted December 27, 2012 This is where I am at present:- A lot to do! Link to post Share on other sites More sharing options...
RMweb Gold chris p bacon Posted December 27, 2012 RMweb Gold Share Posted December 27, 2012 So you built your structure before the floor? unusual. looking at the threshold height I presume you have dug out the oversite inside ? How are you fitting your joists or are they already laid out internally ? We put the floor down as we build so we have a platform to build off of. The building does looks really good, not your average shed. Link to post Share on other sites More sharing options...
RMweb Gold chris p bacon Posted December 27, 2012 RMweb Gold Share Posted December 27, 2012 If you can't tell which is "before" and which is "after"... very funny! Internal size is 12ft by 6ft which is ample for my needs. As it's an old house with combined drainage, I've taken the run-off from the gutter into the top of the soil stack - not perfect I know, and a proper P trap will be installed when the concrete is replaced for something a little more aesthetically pleasing. That will keep the rainwater and the vent apart. CIMG1041.JPGCIMG1043.JPGCIMG1476.JPGCIMG1477.JPG Just a quick question, did you damp proof the exterior wall that has soil against it ? Roof looks fine, modern "torch on" felts have a long life and are nothing like they used to be, 15 -20 year life is easy if they are laid as per instructions. Same goes for modern day chipboard again nothing like it used to be. It is far superior in it's grade and water resistance, as an example the off cuts get used as muckboards for the brickies and the ones on the present site are 3 years old and are left out all the time, they seem to last longer now than the ply one's which delaminate quicker. Link to post Share on other sites More sharing options...
Pete 75C Posted December 27, 2012 Author Share Posted December 27, 2012 Just a quick question, did you damp proof the exterior wall that has soil against it ? The brickwork you can see on the longest side is the only brickwork in that wall. Once the original structure came down, a further 2-3 tonnes of soil were removed and I also dug down around 18". The bricks sit on a reinforced concrete base around 13ft long by 2ft thick by around 3ft tall. I reckoned this would do a better job of holding back the soil than bricks ever would. You can just see the top of the concrete at grass level. Yes, the concrete was damp-proofed on both sides before backfilling with a couple of layers of dpc between the concrete and first row of bricks as well as between the bricks and timber frame. Pete. BTW, the lack of windows suits me just fine - I've had issues with fading in the past and much prefer to work in tungsten daylight as opposed to natural daylight. I know that wouldn't suit everybody - maybe I'm a bit of a Hobbit... Link to post Share on other sites More sharing options...
RMweb Premium Pannier Tank Posted December 27, 2012 RMweb Premium Share Posted December 27, 2012 So you built your structure before the floor? unusual. looking at the threshold height I presume you have dug out the oversite inside ? How are you fitting your joists or are they already laid out internally ? I will have to consider starting a separate thread / blog to describe my method of construction, but basically I have trench fill footings and then six layers of brick (due mainly to slope of garden) up to DPC Level. I then dug out the excess soil to level the ground inside the building.On the longitudinal lengths (Front & Rear) I have another row of bricks inside on which the Floor Joists will sit. I then built the timber frame (4x2) onto a DPC Membrane. Link to post Share on other sites More sharing options...
RMweb Gold chris p bacon Posted December 27, 2012 RMweb Gold Share Posted December 27, 2012 The brickwork you can see on the longest side is the only brickwork in that wall. Once the original structure came down, a further 2-3 tonnes of soil were removed and I also dug down around 18". The bricks sit on a reinforced concrete base around 13ft long by 2ft thick by around 3ft tall. I reckoned this would do a better job of holding back the soil than bricks ever would. You can just see the top of the concrete at grass level. Yes, the concrete was damp-proofed on both sides before backfilling with a couple of layers of dpc between the concrete and first row of bricks as well as between the bricks and timber frame. Pete. BTW, the lack of windows suits me just fine - I've had issues with fading in the past and much prefer to work in tungsten daylight as opposed to natural daylight. I know that wouldn't suit everybody - maybe I'm a bit of a Hobbit... Sounds a good job and won't give you any problems. Brickwork below ground is ok, but the slightest sign of clay heave and it can move, a concrete shuttered wall is a much better bet. Know what you mean about daylight, it's great to work with on a bright day but a bit of cloud and you have to turn the lights on, so you may as well work that way from the start. Link to post Share on other sites More sharing options...
RMweb Gold chris p bacon Posted December 27, 2012 RMweb Gold Share Posted December 27, 2012 I will have to consider starting a separate thread / blog to describe my method of construction, but basically I have trench fill footings and then six layers of brick (due mainly to slope of garden) up to DPC Level. I then dug out the excess soil to level the ground inside the building.On the longitudinal lengths (Front & Rear) I have another row of bricks inside on which the Floor Joists will sit. I then built the timber frame (4x2) onto a DPC Membrane. A sleeper wall, just wondered how you were planning to do it. Loads of ways to construct floors, my room is an extension on the side of the house (4m X 8.5M) it is a brick and block cavity wall construction, the floor was dug out along with the footings and was hardcored, sand, DP membrane and concreted (150mm) then a 150mm layer of insulation was laid with a chipboard floating floor to cover. I laid a laminate floor in Oak so I could see what I had dropped (well worth it !) It didn't need 150mm of insulation but that was to do with the house levels, also it's cheaper and easier to uase than concrete. So whats going in it ? not looking to do the Bletchley flyover by any chance ? Link to post Share on other sites More sharing options...
RMweb Premium Pannier Tank Posted December 27, 2012 RMweb Premium Share Posted December 27, 2012 So whats going in it ? not looking to do the Bletchley flyover by any chance ? No, not the "White Elephant"........................................ Moretonhampstead BR (W). I do have several other railway interests like LMR 60's (Duchesses & Jinties) and also I like the BR Banger Blue period. I'd better not mention 5" Gauge Live Steam Anyway I decided on a BR(W) BLT with a bit of modellers licence thrown in! I think the Banger Blue comes from my return to Railways / Model Railways after a 1968 to 1982 break from the hobby. First started spotting at Bletchley Station 1961/2, seen a few changes! Link to post Share on other sites More sharing options...
RMweb Gold chris p bacon Posted December 27, 2012 RMweb Gold Share Posted December 27, 2012 No, not the "White Elephant"........................................ Moretonhampstead BR (W). I do have several other railway interests like LMR 60's (Duchesses & Jinties) and also I like the BR Banger Blue period. I'd better not mention 5" Gauge Live Steam Anyway I decided on a BR(W) BLT with a bit of modellers licence thrown in! I think the Banger Blue comes from my return to Railways / Model Railways after a 1968 to 1982 break from the hobby. First started spotting at Bletchley Station 1961/2, seen a few changes! Bit further along the Ox-Cam at Sandy for me. Link to post Share on other sites More sharing options...
RMweb Premium Pannier Tank Posted December 27, 2012 RMweb Premium Share Posted December 27, 2012 Bit further along the Ox-Cam at Sandy for me. I grew up beside the Oxford to Cambridge line at Bletchley. Sandy is a very interesting choice, plenty of variation LMR / ER etc. It'll be a while yet before I start the layout, I guess next autumn at the speed I work! Link to post Share on other sites More sharing options...
RMweb Gold chris p bacon Posted December 27, 2012 RMweb Gold Share Posted December 27, 2012 I grew up beside the Oxford to Cambridge line at Bletchley. Sandy is a very interesting choice, plenty of variation LMR / ER etc. It'll be a while yet before I start the layout, I guess next autumn at the speed I work! Yes, but as with Lifeboatman, having a decent room to start with means you don't have to worry about it when you get in there. I found the time spent getting the room right paid off in the end as the comfort factor pays a bit part in whether you go in there or not. Link to post Share on other sites More sharing options...
CUTLER2579 Posted August 14, 2014 Share Posted August 14, 2014 This is where I am at present:- Railway Room.jpg A lot to do! Is that the New CMK Library mate ! Looks Superb. Link to post Share on other sites More sharing options...
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