zoothorn

Ok understood. Thanks for confirming. So when the suggestion is a 'dpm' all I recall is that stiff black rigid textured stuff that comes on a 6" wide roll.. which I can't see how malleable enough to pull over a sharp edge. But is the suggestion a -sheet- over the whole expanse of the osb? does that mean then the same type of plastic DPM (thinner than this rigid textured roll stuff) laid under my extention floor concrete top (poking up I bent up & trimmed then laid PIR on > caber floor): is this what you have in mind? Or maybe the thinner 'vapour sheet' stuff suggested on topside of my ceiling pB (which I can't face doing!)? not sure if this was a 'DPM' per se. thanks, zH

@PeterW hi Peter if you're out there.. was your suggestion like Onoff's 1st sketch.. to put the PIR directly onto my (^) base, within the 3x2 perimeter frame (so this 'frame' sits directly onto the base) >>> THEN the osb covers the lot? [Or Osb goes 1st onto base..). Thanks zoot.

Hi @Onoff cheers for thesees sketch (calming!). Two discrepencies: the Osb goes below the 3x2 & PIR (I think this is how PeterW suggested/ this subfloor his idea). But your idea I think remains the same (& sprung to mind over w'knd) of adding a side to cover the osb edge. And the t&g in your 1st sketch is the wall, not cladding (I dont have an inner load-bearing wall) & so sits upon the 3x2. So any dpc will need to do another 90*. If its thin enough a dpc can maybe squeeze between the cabin floor & wall.. but any thickness & it'll then prevent a tight join between them & stick out sideways.. and/ or onto the 3x2 as well. But if thin & able to be bent 90* out > then 90* down over the osb edge = bingo. Not sure. Yes a floor is with cabin: not great but useable: 3 interlocking sections (2x1 battens with floor slats nailed across ontop) slide together making the floor. So it has double-use: a floor obviously & a 'start' section, to position walls tight around > & build up. Sorry even if I could sketch.. I don't have a cam now to photo it. Thanks alot- zoot

Hi- does anyone know if these osb edges can be covered/ or, what's the best thing to do here? The 11mm board edges will be exposed to weather you see I need to sort this before I can proceed. Osb3 will lie onto of this (^) base. A periphery square 'frame' of 3x2 will sit ontop of the osb. 50mm PIR will go inside the 3x2. Thanks, zH

@Onoff Ok so where there are single nogs/ the 2.4m square for the cabin: osb (11mm) will cover to the edge of this (^) base. Then an outer square of 3x2 (IE, the cabin's 4 walls go upon this). Within this square 3x2 'frame' : the 50mm PIR.

Sorry, a sketch of 3x2 ontop osb? not sure if it would help, even one of yours tbh. plus my camera's rip. Its simply the fallible edge of the osb.. what is usual to 'cover it' to the elements? Ive thought if I extend the 3x2 out so it hangs 1" over edge of the osb, that will hide it a bit- but it'll still get wet surely. (my other Q: shall I soudal-foam fix my PIR to the osb? I need to fix it down really).

Can someone help with what to do with my osb edges, & fixing my PIR: The 3x2 will have a sandwiched layer of osb3 between it & my base, so this edge will be prone to rain. What's best to do? And the PIR 50mm which will be within the outer 3x2. I may have to leave it/ tarp this sub-floor work (trying to get overhanging ash cut before I put cabin up.. not easy with lockdown/ maybe not possible) so should I fix it to the osb I wonder.. soudal LE foam 'dabs' maybe? thanks zoo-t

So how else do you propose killing knotweed growing on stream & river banks here then-? roundup? pull it out? you have no idea Onoff. I have had to or my property would be infested with it by now. And neat glyphosate too is only thing that works, 15x stronger than 'roundup' too (which is all grass needs/ all what I was proposing to use)! Its not next to a stream, the tricky areas I'm mainly talking of ~5m from it. And just needs a weak roundup even @ 50/50 for just grass: I'm not the slightest bit concerned about anything significant at all getting into the stream with the idea.

Anyone know if ground below my base -must- have some sort of weed barrier? Since made end of summer last, all I have is some tall grass coming up thru/ easily cut. Once i have floor on including front deck bit, light will be diminished alot, & I can get under & cut it from the low side with a long blade I guess. Or just spray weedkill when neeeded? I wonder if this growth will naturally just be kept in check being mostly dark underneath. Logistics & expense of a weed layer are ~big I think. thanks.

Exactly- actually it'll be me taping/ filling as only a workshop not perfect is fine for me in here.. if BCO agrees that is. thanks chaps- thread all but over then. miraculously on page1!

Ok this sounds good.. I might just need plasterer in to do my ceiling upstairs only. £saves me.. as surely just 1/2 a day labour to skim it, in these current times, isn't gonna be sniffed at by a plasterer.

Good point. Ok so long as I can go ahead & get the pB up.. I can cross this bridghe later. I'm just suddenly landed with my delivery (including xyz for the cabin job).. not end of next week, but tmrw!! (good tho- but panic on!)

I had thought you recommended 18mm osb for the top layer, back wherever the post is. Not so? good. No 18mm then. 11mm osb3 top layer. Ok so just 'edging with timber' to consider then: so I have two 'end/ edge' profiles of osb top & the btm layer of 20mm t&g I assume this timber attatches to.. but these edges hardly ideal to whack screws or nails into, especially the osb-?

That's great- a relief I can progress/ cross this bridge later then (if needed at all now it seems). thanks

Good job! (ok nod when it comes to taping/ filling my wall boards, I'm gonna be asking a few Q's your way). Good news I can get plasterer to do TE boards then.. don't need to worry & get the damn things up now. Actually thinking on it.. why can't I just tape/ fill & no need for any plastering, like you here then?? I was just under the impression for B.Regs all ceilings had to be plastered, only walls could be taped/ filled. Not neccessarily so then?

Hi Peter, thx for such a quick reply. Just googling 'insulating a cabin roof' & some photos shows 1) adding PIR onto my t&g roof (as it is), then 2) osb layer on top > 3) felt over presumably).. & wasn't your suggestion somewhere similar? thanks- zoot

@PeterW &/ or @Onoff could either of recall your suggestment for my roof? IE going an insulated layer, & osb was it ? so at the moment what I have/ what I pulled off the cabin when decontructing it.. is just t&g 20mm pine sections. Can you remind me of a better plan, maybe using 25mm PIR & 11mm osb? (no need for 50mm & I'm concerned with added weight of 2x 18mm osb sheets). I'm in a major rush too as I need to add to order (plasterboard etc) that's being delivered asap > tmrw!! sorry I will try to find the suggestion now.. but any reply in meantime really helps! cheers zxoot.

Back to the original OP q of the board junction: why couldn't the gap be filled before the plastering? I mean just "extending" the RHS angled end gap where it butts up, onwards 10mm or so? so then you replicate the seamless join as if 1 board split & bent 'perfect' to form this junction. I ask not as a suggestion -I don't have any jurastiction to!- but because I have the same situation of two boards joining like this, & I too don't know how it will be skimmed here.

Hi. Does anyone know - ie from the pov of a plasterer- of any issue with plastering onto taper-edge boards on a ceiling? or, could I not just taper-edge-fill & then its plastered? Reason is: I cannot source 12.5mm straight-edge Soundblock boards (current situation etc).. only taper-edge, so no choice/ have to put on ceiling now. Thanks. zoot

Ok I'm drawing line under this thread now, ok mods? ----------------------------------------------------------------------------------------------- Insulation/ vapour layer/ ceiling/ wall pB prepped & ordered. MANY THANKS chaps. zoot

@Onoff you mean get in more I think! I'm only asking a few Q's but thx for the pointer. Is that the same then/ as a rule you mark on floor, put board up whole, leave your spark to find the cable via drilling after its skimmed-?

Understood. Unfortunately I think your idea came a bit late, I'd put alot of time & searching on the 12.5mm avenue I was driving on that route. I can only go with what's ordered now.. at least I only have 1 layer. Is the idea to cut small holes for the light wires in the board before fixing up, & somehow pull it thru whilst getting board up (I cant see how I could, alone).. or mark/ drill a hole to leave it for electrician to enlarge/ find cable later?

A good idea & easier sections/ considered Peter.. but 18mm total so 20mm skimmed call it = too much. I need to scrimp every 5mm's. The only square-edge pB available was standard knauff 12.5 in fact.. this then for ceiling. So I need to source a skimmer. thx zt

Ok pB ordered/ end next week. In meantime can I ask a Q on 'skimming' ceiling(s). My top room2 above, has a sloping ceiling side section (where rafters form a collar, just one one side) and also a bit of sloped sections around the knock-thru doorway area. So the pB sections join quite abruptly, sloped bits to flat majority. Will a 'skim' be able/ be appropriate? or will a full 'plaster' be needed I wonder. Can a skim navigate the abrupt joins ok? Thanks, zH

Haha! well could do it next week if I go soundstuff now, might be able to get a delivery. or do I wait for 2 more weeks & ask ask & get so many facts- facting me till I fart.