marmic

everything on the 140mm. manufacturers response to question about gap: We’d expect a circa 10mm gap (for your yellow highlighted section) to the underside of the Larson so it wasn’t loading the brick / insulation cover. This could be closed with a compressible foam (compriband or similar). thermal bridge free - absolutely! if you've done this would appreciate seeing a detail please? for increased thickness we'll need to go down as height restriction in relation to adjacent stable block. hence wondering about beam and eps

albeit our walls are much thicker, and with timber cladding

just found this which looks reasonably sensible (actually replicating one of my thoughts but hadn't got any further!) - be interesting to see the other section with beam ends. and not sure what happens structurally at the sub-floor vents!?

nothing built. commence spring once ground dried up! but need to get ahead........... extracts of drawings herewith. 1. timber frame section (ordered) - scribbled bit will be insulation bonded on. May add brick plinth? But probably just insulation as you would with raft and rendered over, or bitumen, or a capping of some sort. 2. SE foundation design (strip footings) - not final, subject to the design drawings for the insulated precast planks - which are overdue and getting nervous! 3. strip footings on plan with direction of planks.

Good afternoons, I have also asked same question on an old post, but thought it worthwhile adding a new one too! We are using a larsen truss system from Timber Innovations (ie all the load on inner 140mm stud) and have to have suspended floor due to heavy clay, trees, hedges. We are at passivhaus high performance (won't quite meet certified due to form factor - not huge and single storey). Current plan is preinsulated planks (avoiding screeds etc) with timber frame sitting directly onto edge - so almost replicating a raft, but suspended. But getting very nervous due to long delays with design (need for coordinated drawings for submission to building control), therefore now urgently exploring other options. Seems to be a few beam & EPS products out there - but how to detail edges with no traditional masonry/brick, where to sit timber frame, and prevent/minimise thermal bridging. Plus dpc/dpm/ventilation detailing.......... I'm probably not the first one to be doing a lot of head scratching on this topic! Would appreciate any pointers please... many thanks kr.........ma

good afternoon, would be very interested if resolved and what the conclusion was please? I see things went off topic a bit! We are using a larsen truss system (ie all the load on inner 140mm stud) and have to have suspended floor due to heavy clay, trees, hedges. We are at passivhaus high performance (won't quite meet certified due to form factor - not huge and single storey). Current plan is preinsulated planks (avoiding screeds etc) with timber frame sitting directly onto edge - so almost replicating a raft, but suspended. But getting very nervous due to long delays with design for coordinated drawings and building control, therefore now urgently exploring other options. Seems to be a few beam & EPS products out there - but how to detail edges with no traditional masonry/brick, where to sit timber frame, and prevent/minimise thermal bridging. Plus dpc/dpm/ventilation detailing.................. kr.........ma

thanks Nod, spoken to a building control surveyor today - he tells me there isnt any reg that covers this - bonkers! when there should be something there isnt, yet many regs are simply rubbish! have been talking to likely window installer again since, they aim for 5deg, albeit ours will be 4 due to depth - but fine as has upstands to rear and sides (ends) to acts as a tray. and have clarified fitting details. better than packer under window as weakens the thermal properties. He even said he's seen flat or sloping wrong way! No surprise there.

Hello all, Getting close to making decision on aluclad windows and doors (for passivhaus high performance) - but can't find anywhere in regs / nhbc etc what the min pitch needs to be for window sills. Anyone please? (for England if that makes any difference) Timber frame structure with flat reveals. Window frames will be set mid span of insulation from which it's circa 202mm to face of timber cladding. The sill itself (which is aluminium RAL finish with upstands at ends as well as back) will be circa 195mm allowing for a 30mm overhang* * another one that seems to be grey area - is 30mm correct? here's hoping somebody has found the official answers?! many thanks,

Long shot this - hoping there may be somebody out there who has tried something similar? Or any educated opinions and ideas please?! We installed some earthpress grass grids about 4 years ago (vibrating roller to push in - link below) - looks like being marketed differently now. Tracks to park/drive on, walk, and for horses. We are on heavy clay and some areas have over time sunk a little - or the grass and mud risen, whichever way you look at it same difference! (areas on a very slight gradient and less wet still pretty good, but still bit muddy. fortunately this is the horse bit 🙂). Not sunk deep and still stable but no longer practical to drive on with road tyres! And walking on requires wellies at the moment. I'm thinking maybe run some gravel boards to edges and add a layer of 6f5 or similar. Thinking is the grids will work as a base and the aggegate will lock into the grids. Or will it make a bigger problem and go through and sink pushing up more mud, and/or push the grid down? Or maybe lay a woven geotextile membrane straight onto the muddy grids first? I can't decide what I think and going round in circles! 🤪 Want to avoid an expensive mess! The plan was for more grid extending a track but I'm now thinking we'll probably dig 2 trenches with french drains as wheel tracks - we can run them downhill fortunately. Then maybe grids over that (albeit if we do it well probably not necessary). Hope there are some opinions, ideas, and/or experiences out there please 🤞

hello again all, starting to think perhaps supply only too - if nothing left on the table at least it keeps some control ! Has anyone experience with 21degrees (formerly green building store) please? possible one stop shop for fenestration, mvhr, and PV........ website says all the right things kr.............ma

I think the problem is with your commercial background your used to calling the shots. not at all - on the other side of the fence actually - and with made to measure high end systems! (rarely used in resi) in this self build world your a very small fish, you will only be ordering one set of windows, not a continuous stream. they don’t really need to be that flexible. absolutely - still not right though! if we were all to do this more than once needs a buying group setting up!

great conversation with Uniwin - unfortunately we are too far south for them to install. But if we end up going supply only route will definitely be talking to them!

great conversation with Uniwin - unfortunately we are too far south for them to install. But if we end up going supply only route will definitely be talking to them!

thanks Mike - didn't occur to me such companies would accept credit cards! So yes some protection that way. Most clearly see us as retail transactions then and presume build in the bank charges. All seems very strange and unreasonable to me doing what I do for a living (including providing due diligence advice to prinipal contractors, big and small). Guessing there's been lots of window industry fingers burnt? Albeit going back in time there certainly used to be a lot of dodgy players out there too! Hopefully I'll find time later to explore further...............

ps - and for supply only credit completely normal with builders merchants!

thank you - will be getting my head into this saturday with plenty of coffee!

thank you. on my call list for tomorrow 😀

thank you for responses - any more recommendstions welcome please. will be trying to find time to make some calls tomorrow. ref payment terms on supply and installed nothing like buying sausages! More comparable perhaps with a meal in a restaurant - you woudn't accept or pay for it if dished up on a mouldy plate or it was raw chicken with grass sprinkles for veg! Yes a ridiculous analogy I know - but would you pay in advance for say some decorating work - the answer has to be no! I work in the construction industry (mainly commercial) for a specialist sub-contractor and agent for a number of manufacturers - it's completely normal not to pay in full until work complete and to a satisfactory standard and handed over snag free, then generally retention (often at 5%) for defect period. usual scenario is 50% released at project PC, 50% at 12 months! terms usually agreed on credit checks / risk - so yes occasionaly in full in advance with stage payments. Vesting certificate generally then required. The window company mentioned didnt even know what that was! So yes I'm finding it a bit of a culture shock how suppliers and manufacturers treat self builders and it seems quite a number of them assume we'll all do exactly as we are told! Yes of course payment terms will be less generous as companies need to protect themselves to an extent against individuals not paying, but paying for everything in advance is not reasonable if supply and install! Which I see as a de-risking exercise (as long as payment terms leave something on the table!). Supply only yes a different conversation, but then if a third party used for install and it goes wrong they will be blaming each other. And yes everything will be throughly checked for correct install and procurement undertaken with very careful due diligence! Timber frame terms renegotiated - everyone happy. Another timber frame company nearly secured the order until they insisted on a ridiculous contract being signed (putting all risk on me and making a mockery of a so called fixed cost) and unreasonable payment demands............ The customer should be issuing the contract! BE CAREFUL OUT THERE 😀

Hi all, have added my question to an existing discussion but thought worth posting new too: Any recommendations please for passivhaus timber windows and doors supplied and installed (properly!) with sensible payment terms (alu-clad finish ideally). Had been talking to a company which seemed a likely choice, but rather arrogant in end with full payment required in advance of install, and won't budge. And stating they won't make mistakes and if there is an error it will be the fault of the timber frame company! many thanks..............m

Hi all, have been trawling around looking for MVHR design info to enable me to work it out myself with a view to buying unit and ducts etc and fitting - but struggling to find guidelines. Assume key points will be room volumes / positioning within rooms / duct volumes/lengths. (we are building a circa 100m2 single storey passivhaus). Hoping somone might have some pointers please? I'm about to look at in detail and need to make some decisons. Mostly exposed ducts - plant room for the unit itself. duct layout should be straightforward with primary straight runs through central hallway with branches off into rooms I did approach a few companies at early stages some time back now wanting a conversation - but just received quotes (useful for cost plan but not requested!). Unfortunately they just give lump sums and can't say what they've allowed for in terms of design - but won't design until ordered, and for a fee! Seems like a rather cloak and dagger market! And commisioning? Really necessary? Surely can't be that complicated!? We aren't going to buy something without due diligence and understanding what we are getting so finding it all very frustrasting / strange!! Or failing a diy design and buying components option 2 is a supply and install company who will actually have a proper conversation and discuss reuirements in detail - hoping somebody has had some good experiences with a company that is more up front and can provide a recommendation please? many thanks

Hi all, glad I've found this discussion which confirms to me yes it's a very mixed bag out there! We commence soon on a timber frame passivhaus project and need to make some decisions on windows/doors. Seems to be plenty of experience here and wondering if anyone can narrow down which suppliers/manufacturers offer supply and install please to high standards, which in theory de-risks things. Have been trawling around websites and straightforward info rarely obvious. (i wouldn't place two orders for separate supply and install). And with sensible payment terms. Currently only spoken to one (no names!) at early stages including a quotation. On paper seemed a very likely choice and i don't doubt the quality (albeit not checked further as yet) but having spoken further with them they insist on unreasonable payment terms wanting the whole lot before anything installed, which in my book is completely unreasonable as leaves nothing on the table as a lever if they get anything wrong - which the chap I was talking to said was not possible, and that if there were any errors it would be the timber frame company! Arrogant? many thanks