inspired by shed th...
 

[Closed] inspired by shed threads, do you think its possible for.....

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You could, but equally you can have them all in line.

 
Posted : 20/08/2016 7:10 am
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how mate? cant get my head around best way of arranging the posts, 4x2 ring beams and intermediate struts to make strongest structure.

the ony way i can see of having 4x2 nailed all the way outside the posts and have the struts inline with the 4x2 is by actually nailing more struts up the side of the posts too for the cladding to nail to. which firstly i dont think would look as good, and secondly wouldnt actually make it any stronger, in effect id just be pushing the cladding out a little. make sense?

 
Posted : 20/08/2016 7:26 am
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You can sit the ring beam on top of the studs.

I wouldn't worry too much about strength. Once everything is up and the cladding is on you'll have a box like structure and it's hard not to have a strong box.

 
Posted : 20/08/2016 7:29 am
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thats how ive been thinking itd be originally, floor beam nailed to outside of posts, roof beam above it and studs/struts in between the two, fastened with 4 angle clips, 2 top and bottom. all in line.
but..... then if im cladding the outside, theres no post at the end to nail onto as the cladding is 2" off the posts.

or..... i could clad the [i]inside[/i] of the gazebo instead (my preferred look as all posts and struts would be invisible) but then the cladding would be butting up to the side of the post with nothing to tack onto at the end.

EDIT: i spose all this can be sorted later on, can we all agree that the length of gazebo [i]cannot be any more than 4.8m[/i] as this will be the length of the decking plank that will be the front of the floor section? end of?
so the distance between posts will definitely have to be 4.8, minus 4" (100mm), minus the thickness of two decking boards (used to finish the edges by being placed vertically)
so the whole length of the gazebo floor on view will be 30mm/4.74m/30mm to add up to 4.8 on the surface.

 
Posted : 20/08/2016 7:37 am
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I haven't read through the entire thread so don't know if anyone's mentioned it - the size quoted for most timber is nominal; 100mm x 50mm is more like 96mm x 47mm.

 
Posted : 20/08/2016 9:12 am
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yeah i saw that whilst looking for sizes, seems strange. i just assumed 47 x 100 was 4 be 2 cos its near as dammit, but i couldnt understand why they also had 2 be 2 listed as 50 x 47.

 
Posted : 20/08/2016 2:52 pm
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as promised, heres the first progress shot. 3 posts in, my mate hasnt been able to come over to help yet so im trying to do what i can where im fairly sure im not making a booboo.......

[img] [/img]

[img] [/img]

frustrating as im at work again tomorrow for a few days, so i wont be able to do any more now til friday.

todays questions......

1. when i start constructing the floor ring beam and support joists, can they lay directly onto my concrete slab (left of the site), or will they need raising slightly to avoid damp? itd be easier if i could work straight off the concrete but if i have to raise it ill need to work out a way of supporting it in various places just an inch or so off the slab.
certainly to the right of the site where the grounds lower and uneven ill need support at the right height. the suggestion earlier in the thread of postal tubes filled with concrete may be the right answer but id rather build it first, see where i want the supports and how high, then sort it.

2. mcmoonter suggested using nails for all my 4x2 beams which im happy to do. member of family has told me he can get me a load of 4" screws tho, so if cost isnt an issue are screws a better bet?
i assume whether its nails or screws, 4" is the right length, to go through 2" thick beam and into a 4x4 post?

3. 4" screws will be big old bits of metal. i assume id have to drill pilot holes for each one? would i have to drill pilot holes for nails too or just bang em in?

thanks

EDIT: i realise my posts arent going in in the right order, id be better off with the big oblong first and then put my side posts in to match, but my other 2 end posts to the left of pic will be postcreted in and im loathe to do this without the nod from my 'project manager' 🙂

 
Posted : 21/08/2016 8:08 am
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4. just pricing up roofing materials, can someone explain this to me please? [url= http://www.listerstimber.co.uk/onduline-roofing-green-2000mm-x-950mm-855mm-cover-c2x14436427 ]onduline sheets.[/url]

sizes show its nearly 2m x 1m yet coverage says 855mm. dont know whether thats sq metres or what, and how somwthing 2x1 can have a coverage of less than 1.

5. an earlier post on this thread suggested that it may sag if not put on OSB or somethings. if i have a pent roof and it slopes backwards, youll only ever see the inside material of the roof, so itd be pointless using onduline. so i think my choice is [i]either[/i] onduline or OSB, not both.
id prefer onduline but itll depend on the answer to Q4 ^^^ 🙂

6. never seen shiplap up close so im going on google pics here, but am i right in thinking the profile allows a fair manipulation for different widths? so i could overlap them by more or less to fit into whatever gap i have?

 
Posted : 21/08/2016 9:30 am
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855mm allows for 15mm (? 3 corrogations of overlap), the length will give 1985mm if overlapping. If using it make sure you support it as per manufacturers spec otherwise expect it to sag if you skimp on supports.

 
Posted : 21/08/2016 10:01 am
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6. never seen shiplap up close so im going on google pics here, but am i right in thinking the profile allows a fair manipulation for different widths? so i could overlap them by more or less to fit into whatever gap i have?

Depends. The cheaper stuff is just tapered board so you can vary the overlap. Most has a machined lip so one board sits on another with a built in overlap. A table saw comes in handy for the last board or you can just overlap it in a casually bodged way. It's a shed. Nobody but you will ever notice... Just as long as it doesn't keep you up at night knowing what you've done...

 
Posted : 21/08/2016 10:08 am
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thanks chaps, very helpful, should be able to work out an exact price from that. is there any reason the onduline needs 3 'corrugations' overlap? if width was tight can you get away with 2 you reckon?

also any takers for Q's 1-3?

cheers

 
Posted : 21/08/2016 6:24 pm
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If the slab isn't usually under water you're fine to lay them on top.

Screws are preferable to nails generally. 4" will be fine,

It depends on the screws if you need to drill first. I always buy screws you don't need to drill (timber screws rather than wood screws). It more than doubles the amount of work having to pilot drill holes. You won't need to pilot drill for 4" nails (6" you probably would have to).

 
Posted : 21/08/2016 6:28 pm
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Ah didn't know there were different types of screw, wood and timber. Thanks a lot, much appreciated

 
Posted : 21/08/2016 7:20 pm
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struggling for help with my shed at the mo as my mate cant make the days i can. was hoping we'd have a good day at it friday but now looks like ill be on me own. i may have to do more of this myself than i thought!!

with that in mind, i may have to sort out the roof ring beam myself. floor ring sort of sorts itself out i hope, but not sure how high or what angle to do the roof. ive pretty much decided cost will dictate itll be a pent roof, either covered in OSB plus felt, or onduline with nothing underneath.
if i had to make a guess id say make the 4x2 ring 7ft at the front, and 6ft at the back. ive nothing to back up these sizes, ive plucked them out the air.

any comments on this please?

thanks

 
Posted : 22/08/2016 7:06 pm
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Where are you based?

Edit : Also...

either covered in OSB plus felt

I'd go for EPDM over felt every time.

 
Posted : 22/08/2016 7:07 pm
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im in lincoln mate. and ill look into EPDM, havent heard of that so far.

thanks 🙂

 
Posted : 22/08/2016 7:54 pm
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If you can get a gap between concrete and beam, airflow always helps. Just space it up temporarily with off cuts to get it level, then fix.

Think my shed at home uses 150mm self pilotting screws and I shoved coach bolts in because I had them.

Do put enough supports in for the onduline. Mine sags a little as I am about 6" over stretched due to being too lazy to grab another timber from the barn when nearly done. That said, it's fine. Height wise it probably goes from 7'-6'. Not a lot was measured, just used bits of timber as templates.

Finally, there is no consistency in timber measurements. We cut 4 different lengths of 6' for different buyers, and sell by weight, volume or hoppus and it will all be summarised as something else for easy invoicing.

 
Posted : 22/08/2016 9:19 pm
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If you can get a gap between concrete and beam, airflow always helps. Just space it up temporarily with off cuts to get it level, then fix.

doh, that had been a comfort to me thinking ive already got my support, my concretes level, bobs yer uncle :-/ you say space it up [i]temporarily[/i] then fix. ok but surely i need permanent support underneath too in various intersections? i cant have a 5m X 3m floor all unsupported surely, just fixed on with 2 x 4" nails/screws at the ends of each joist??

Do put enough supports in for the onduline.

yep, will do. if each sheet is roughly 1m wide im guessing every half metre then?

Finally, there is no consistency in timber measurements.

thats scares me a little, im sizing this up to suit supplied timber sizes. dont mind if theyre a bit too long but itd be a disaster if they were too short!

thanks

 
Posted : 23/08/2016 6:06 am
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im in lincoln

Ah, okay. A few counties too far.

Good luck with the build. Enjoy it - carpentry is good for the 'soul'.

 
Posted : 23/08/2016 7:48 am
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thanks for even considering helping, much appreciated, some great people on here. makes me think i may just get it built one way or another 🙂

bring on friday!

 
Posted : 23/08/2016 9:03 pm
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You've got uprights every metre and a bit to fix it to. Mine is about 4.5m span, just attached to corner posts. Admittedly it's a 6x2 and I had to jack it and put in a prop at the front (sloping site) after it sagged a bit under the weight of an old barn door and a couple of double glazing units, but you have far more posts to attach to and share the load.

The corrugations should be square to the supports, nail through the highpoint of the corrugation. 50cm sounds like the figure off the spec sheet I ignored.

 
Posted : 23/08/2016 9:18 pm
 5lab
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i rested my flooring joists on bricks (spaced at 1 foot centres) to allow a little more airflow. Think they're 30p each or something. cheap and solid.

for screws i'm using decking screws for longer reaches, and external zinc plated screws for shorter (turbogold xts) - ie fixing the cladding. someone will probably be along to tell me they're wrong, but theyre cheap enough to use lots 🙂 impact driver meant I didn't need to pre-drill anything

out of interest, what are the clamps for? my sheds nearly done and I haven't used a single one yet..

 
Posted : 23/08/2016 9:26 pm
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out of interest, what are the clamps for? my sheds nearly done and I haven't used a single one yet..

i havent been able to get hold of any yet but i can see why theyd be useful, especially if ill be working on my own a fair bit. i envisage a 4.8m length of wood, clamped at each end onto the posts, me sticking a level on it and then going from side to side tapping up or down to suit. then screwing into place.
or even clamping both sides (so 4 clamps) and ensuring the bit thatll go between them will be right length, level etc.

with that in mind im gonna see how much 4 clamps are today in B&Q/screwfix etc.....

decided im gonna try 4" screws first rather than nails, just for the reason that i can unscrew them if i make a booboo.

also i was going to postcrete 2 end posts only, as theyre the ones nearest the fields/cliff that take the brunt of any winds. im now considering not doing so for the reasons above, 'moveabilty when wrong' 🙂
hopefully the weight of all that wood in the earth will be heavy enough to not move.

 
Posted : 24/08/2016 5:07 am
 5lab
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fair enough, i've just been fixing one end with a screw (not tightly) then wondering to the other end, levelling it, and whacking a screw in there. Once the first length of cladding was in, each one was just stacked on top of the old one, then lifted 2mm to get to the right height.

I also found cutting to length roughly (say 5mm over), fixing, then cutting them all to the correct length in one go with a circular saw was a good way to get a really neat finish..

 
Posted : 24/08/2016 4:54 pm
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good idea, however i dont have access to a circular saw. ill be using an electric mitre saw so the wood will need cutting to size beforehand.

as they say..... measure twice (then three times then four), cut once 🙂

 
Posted : 24/08/2016 7:30 pm
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as promised, more progress pics.....

had a good day today, my mate came over and helped a lot, certainly got me on my way and i can do a lot more myself now im sure...

all 8 posts are in now, end 2 are postcreted, and floor ring beam done, started on the roof.

[img] [/img]

[img] [/img]

dunno how it happened but the post screwed into the concrete ended up waay out plus the bolts never really caught the metal plug to tighten, but....that seems to be the good thing about wood, theres always a work around so ive screwed a bit of 1" strut to it, it wont be seen anyway 🙂 its still as secure as the wood in earth i reckon.

the 4" screws given me were spot on, screwed into the wood like butter, so ill be using those wherever i can. i also bought some 6" quick-clamps from screwfix which are spot on too.

really feel on a roll now and want to get cracking again, but... bittersweet, im off on holiday before i can do any more now, so itll be a couple of weeks before any more pics.

thanks a lot for all your help, its invaluable.

 
Posted : 26/08/2016 6:13 pm
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on holiday at the mo but doesnt stop me thinking thinking thinking.....

i was thinking id be connecting all joists to the ring beams by screws into the ends of the joists. then i read about using joist hangers, and that screwing into the ends reduces strength by a third etc...

opinions from the experts please? 🙂

 
Posted : 05/09/2016 7:13 am
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Id just nail them, a couple of nails through from the outside of the ring beam into the end of the joist then some cheek nailed through the joist back into the bean on each side.

Use a block of wood clamped beneath the ring beam to support the joist at each end. Make a spacer so the centres of your joists are at 600mm centres or what ever the flooring material is.

I'd still nail a length of 4x2 vertically between your floor and roof rails, midway between your 4x4 posts, to give more support for your cladding.

 
Posted : 05/09/2016 8:08 am
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back from hols, nice weather today, so had a full day at it.....

[img] [/img]

[img] [/img]
got all the floor joists in and the noggins. took ages breaking up different thickness slabs we got lying around in the garden, to use as supports. theres all sorts of stuff under there, bricks, slabs, and where i couldnt find anything the right thickness i made little tapered chocks. not convinced theyll stay under nice and tight as the wood moves about, but ive got that many other bits of concrete and bricks that its pretty solid.
no comments please on state of garden, washing on line, or mrs expunk sat on her a*se while im grafting 😉 its a building site at present, itll all be tidied on completion 😉

[img] [/img]
also had time to sneak a few decking boards on, but ill have to wait for my mates tools to do the nearest couple as theyll need jigsawing around the posts.

I'd still nail a length of 4x2 vertically between your floor and roof rails, midway between your 4x4 posts, to give more support for your cladding.

yup, ill do that when i know exactly what size the cladding needs to be and thus where theyll need joining. cladding will not be long enough for full lengths so im thinking rather than have em all join in a line, ill do one from one end and finish with an offcut, then reverse it for next one up etc etc.

tomorrow im hoping to get cracking with the shed side of it, thats a lower floor and a couple more posts to put in.

still not decided on roof yet so wont put roof joists in until i know where theyll need to be positioned.

thanks

 
Posted : 11/09/2016 7:19 pm
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It's looking more like a shed with every post. Keep at it, winter is coming.

 
Posted : 11/09/2016 8:47 pm
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another hard day at it with my mate. half the decking now done (discovered 9 damaged boards so waiting now for them to deliver some swapsies) and the shed structure nearly complete. door and window frames put in, tops of posts sawn off and the shed floor joists in.

[img] [/img]

have to start thinking bout roof now as ill need to be putting some roof joists in and need to know widths for connections.
none of the top can be seen, so all im bothered about is it being waterproof and 'not looking sh1t' from the inside.
with that in mind my mate has suggested 5mm ply as base layer, followed by thinnish OSB, then felt on top.

anyone care to comment on that at all?

thanks

 
Posted : 12/09/2016 6:16 pm
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Just use a 12 or 15mm external ply unless cost is a issue just use Osborne and finish the boards on the middle of rafter.
Rafters minimum 400mm oc.

 
Posted : 12/09/2016 7:06 pm
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If you can get away with it put some diagonal braces in..

 
Posted : 12/09/2016 7:09 pm
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Just use a 12 or 15mm external ply unless cost is a issue just use Osborne and finish the boards on the middle of rafter.

cost [i]is[/i] an issue, but im prepared to spend a bit more to have a better finish. how does 12mm ply compare with OSB pricewise?
whats osbourne?

Rafters minimum 400mm oc.

and

If you can get away with it put some diagonal braces in..

just been thinking bout that in the bath (its where all the best thinking happens...) and ive started wondering about the weight of the roof. the more rafters i put in, plus diagonal braces maybe, all adds a big heft to the weight of the roof. ive started thinking that all that weight is supported in the main by 4" screws.
all that weight is on the roof ring, which is screwed to side of the posts. ok, shed side ive got a few more beams built into the structure, but gazebo side theres nothing.

should i be worried?

 
Posted : 12/09/2016 7:18 pm
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Osbourn = osb auto correct sorry.
I'll have a quick study of your build..
Re rafters..what's the span?

 
Posted : 12/09/2016 7:32 pm
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the whole structure is roughly 7m X 3m. (split is roughly 5m gazebo, 2m shed)

 
Posted : 12/09/2016 7:43 pm
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4" screws have a high shear strength..what size screws are they 100mm x 5 or 6mm. If no moisture gets in to them they won't rust. As for the braces I'd be more concerned about the side load caused by wind over the months years etc..
Treated 100 x 50mm C24 at 400mm centers will be good for any snow-load that might occur in this country. 15mm ply will aid roof strength better than osb.

 
Posted : 12/09/2016 7:44 pm
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Will the roof be over the decked section ?
I'd personally use 150 x 50 C24 @ 400 oc but as you've already the 100mm on the ring I'd reduce the measurements 100 x 50mm treated C24 305mm oc and use ply lengthways front to back and stagger the joints..ie. 2.44m + 0.56m ( 3m ) then on the next row.start with 0.56m + 2.44m...

 
Posted : 12/09/2016 7:54 pm
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just been out to garage to look. theyre reisser cutter screws, yellow tropicalized, 100 X 5mm.

good enough to take that weight do you think? would i add twice the roof strength if i stick 4 screws in per post instead of 2?

ill look into 15mm ply costs. thanks.

EDIT: looks like we were typing at the same time..... dont really understand all that, have you got a link to the boards youre suggesting? and yes, the roof will cover everything, its the full oblong.

EDIT EDIT: ah i understand a bit more now, youre on about preferring 6X2 but accept id be using 4X2 yep? and all the wood ive got is tanalised, not sure how that compares to C24.

and your 305 oc? youre suggesting 4 joists per board??

what thickness and quality ply would you suggest?

thanks a lot

 
Posted : 12/09/2016 7:56 pm
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Looks like you are doing a good job, keep the pics coming as you go along!

 
Posted : 12/09/2016 8:08 pm
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The boards I'm suggesting is ply. A full ply sheet measures 2.44 x 1.22m. The roof slopes front to back and is 3m long. This would mean if you put a ply sheet on lengthways front to back you'ld be left with a 56cm cut. The piece of board you have left you cut off a 56cm rip and start the next row with this. You'll get 4 56cm wide strips out of a full sheets of ply.
Over a 3m span I'd normally use 6x2s @ 407mm centers but you've already 4x2s forming the ring so I'd span the 3m with 4x2s but bring the centers down to 305mm.
Put noggins in to prevent twisting.

Edit..we're typing at the same time again..over the 3m span I'd definitely go 305 centers..on the shed bit you have a supporting wall so 407 centers will be fine.
Don't go to travis for your ply. I'm trade and buy my ply from wickes at normal prices as it's cheaper than TP.
Wbp ply if you can get it if not Hardwood ply from wickes..

 
Posted : 12/09/2016 8:15 pm
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thanks mate. just looked at wickes and cant see any 15mm hardwood ply there at 2.44 X 1.22.

google shows Travis Perkins do sell them. ive had all my wood from there so far and have been haggling on price and knocking price down so have a decent relationship with them.

how much would you be happy to pay for 15mm sheets if i give em a ring and say i wont pay any more?

 
Posted : 12/09/2016 8:36 pm
 5lab
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i finished my roof last week, used EDPM instead of felt - cost more, but was pretty easy to lay, and given the amount I'd spent on the rest of the shed, I figured a longer lasting, more waterproof solution was best

 
Posted : 12/09/2016 8:46 pm
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[url= http://www.wickes.co.uk/Structural-Softwood-Plywood-CE2%2B-18x1220x2440mm/p/120945 ]wickes 18mm ply[/url]

Last time I asked TP for this they wanted £50

 
Posted : 12/09/2016 10:06 pm
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i saw that mate but noticed its softwood. TP is hardwood. is softwood still ok?

 
Posted : 13/09/2016 5:59 am
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It says it's rated for external use so yes..

 
Posted : 13/09/2016 6:48 am
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What about OSB3? Cheaper than ply.

 
Posted : 13/09/2016 7:06 am
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wickes 18mm ply

Last time I asked TP for this they wanted £50


so that works out if i buy 9 boards at £24 each, £216 if my maths is correct. just rang TP and asked them for their price, i asked for WBP and was quoted £226 inc vat, so not tooo much difference.
the quote from them is shows it being.... '529899 SELEX B/C STRUCTURAL RADIATA PINE
PLYWOOD 2440X1220X18MM E1'

do you know from that description whether that is indeed WBP and if its any better or worse than the wickes stuff?

What about OSB3? Cheaper than ply.

yes itll be cheaper, but wont look as nice sat inside looking up at it.

thanks

EDIT: just done a proper measure, with a bit of overhang at the back, its 6.7m X 3.4m.

 
Posted : 13/09/2016 8:46 am
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change of plan for the roof. ive already got two 18mm OSB boards for the shed floor, 8ft X 4t and it takes 2 of us to lift one, theyre heavy!

i really was getting quite worried about a dozen+ big 4be2 joists plus 9 of them boards, thats some weight!
i started questioning why i need that weight (i dont think i do), i only want a cover, and the lighter the better.
i started looking at onduline again, got a quote from a place online, realised wickes were cheaper, realised my mate has a 20% discount at wickes and on impulse rushed through a purchase before he goes abroad tonight for a couple of weeks.

so, im having 16 green sheets delivered tomorrow. should have ordered the screws too but didnt want to p1ss my mate about with too many things when he should be packing 🙂

did it all quickly, hope my sums are right. each sheet is 950 by 2m (950 becomes 850 after overlaps). i figure 2 of them per 850 width will give me the depth i need with plenty to spare. and 8 of those comes out at 6.8m, i need 6.7m. think im ok. now have to work out how to fit these things, may need less actual joists and more thinner wood going across, not sure yet......

EDIT: oh, and at £179 for 16 sheets im happy with that.

 
Posted : 13/09/2016 5:14 pm
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Wouldn't of been my choice of material for a pent roof but hey ho.

 
Posted : 13/09/2016 8:19 pm
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yeah dont know if ive made a booboo or not, as i say it was a snap decision driven by my fear of overloading the roof ring with too much weight.

the dynamics of fitting it tho and all the accessories may make it dearer in the end :-/

 
Posted : 13/09/2016 8:56 pm
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ok, this really is 'make it up as you go along'..... 😀

ive cancelled the onduline. looked at how you fit it (on purlins which are mounted on top of joists) and realised ill struggle to stop the wind getting underneath it, [i]and[/i] to dress it well enough afterwards without more wood on the ring beam. im stumped now.

ive mentioned i want the roof to be as light as possible as i dont particularly trust the weight of a dozen 4be2 joists plus 9 sheets of 18mm ply on just screws. i was awake half the night thinking bout this, its not doing me any favours 😀 i considered last night that its probably an even worse idea than i thought before. rather than the whole ring taking that weight, really all the weight of that wood is just on the front and rear beams, as each beam is individually screwed to the posts, theyre not connected to each other.

my gut feeling now is to go back to the ply option but as thin as poss, 5mm or somethings. im pretty sure youll advise its a bad idea but why? if its supported well enough i cant see half metre sections sagging for instance.

could i have your thoughts on that please?

thanks a lot, we'll get there in the end, all part of the journey 🙂

 
Posted : 14/09/2016 6:20 am
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Firstly if the strength of the screws is bothering you whack a coach bolt or a bit of studding through the joint. Easy to retro fit and will significantly strengthen the joint.

Thin ply isn't a great idea. It'll take its own weight to start with but over time will sag. I'd say 15mm minimum but 18mm is often cheaper as its more readily available.

Once you've got a solid deck any number of waterproof top layers will do. Felt roll (or shingles if you have a pitch), epdm or fibreglass for a tougher but more expensive finish.

 
Posted : 14/09/2016 6:52 am
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I wouldn't worry about the weight of the ply. A foot of snow however...

 
Posted : 14/09/2016 7:33 am
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Firstly if the strength of the screws is bothering you whack a coach bolt or a bit of studding through the joint. Easy to retro fit and will significantly strengthen the joint.

good idea, ill do that.

been googling again..... what about [url= http://www.wickes.co.uk/Wickes-10mm-Twinwall-Polycarbonate-Sheet-900-x-3000mm/p/105909 ]polycarbonate sheets[/url]? they say theyre for shed/garage roofs etc, would they take a foot of snow/not look sh1t? think they do opaque as well.

i picture it looking a bit like this from inside the gazebo which seems acceptable. even better if opaque.

[img] [/img]

 
Posted : 14/09/2016 9:02 am
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I've just used twinwall 10mm polycarbonate sheet on a greenhouse. Light weight and easy to work with. The sheets have a male/female edge so you can butt join them. Have a look at polycarbonate button fixings to attach them with.

It's the size, spacing and pitch of the timber that will give you the strength rather than the roofing material.

 
Posted : 14/09/2016 10:15 am
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finished the decking last night, theres nothing else i can do to it now til i sort out more wood for the roof and cladding. spent this morning digging up grass and replacing with gravel so it gives it its own 'area'.

[img] [/img]
that pic maybe shows the end nearest the field a bit better too, with the 3.4m span ive got for the roof beams. looking at it now it just seems ive maybe made it a bit wider than i should 'just cos i could'.

It's the size, spacing and pitch of the timber that will give you the strength rather than the roofing material.

which i spose is what im talking about above. gut feeling is ill still use ply, 12mm compromise, but ill look into polycarbonate. had a quick look on youtube and it does seem a bit of a faff with all the edge and joining beads, tapes etc. and they wont come cheap either.

 
Posted : 14/09/2016 1:19 pm
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That's looking great.

 
Posted : 14/09/2016 1:27 pm
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thanks mate, yep, im pleased with how its going.

next question..... after talking it over with my mate, ive decided to stick with ply for the roof, but thin ply first (4mm) topped with 8mm OSB, and staggered for strength and then that topped with felt.
got a quote for all the ply, plus some decent felt (38kg mineral if that means anything to anyone?) but im unsure about the felt adhesive. i thought id just be tacking it down with clout screws, and then using adhesive on overlaps. reading up on it suggests i should use underlay too??
is this just belt and braces, ive never seen felt plus underlay on any other sheds, so can i get away with my original plan, or do i really need to splash out another £100 or so on underlay? :-/

thanks

 
Posted : 16/09/2016 12:31 pm
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oh and also, do i have to spread bitumen/adhesive over the whole roof first or just the overlaps?

clout nails directly into felt through to the joists, or do i use wooden battens to hold the felt down?

thanks

 
Posted : 16/09/2016 6:33 pm
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just popped into builders yard on way home from work this morning to look at shiplap and ply. disappointed to see they dont do treated shiplap, id always thought they did, but ill just use another yard for that then.

also a bit dismayed to see just how flimsy 4mm ply is. it was warped and bowing all over the place on their pallets, so thats making me think i should just stick with 12mm ply rather than 4mm ply/8mm OSB and risk a warped inner lining at some point.

would appreciate thoughts on that as its your opinions and invaluable advice thats helping me out on this bad boy 🙂
also answers to above questions re underlay/bitumen/adhesive etc much appreciated.

thanks a lot

 
Posted : 17/09/2016 8:04 am
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When I've done sheds with felt I've never used underlay and just used that black sticky stuff on the overlaps, IANAR 🙂

 
Posted : 17/09/2016 8:08 am
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The thinnest ply I've uses is 9mm, but... It's the wood you screw the ply to that gives it the rigidity. 4mm will be fine if you've got the noggins.

 
Posted : 17/09/2016 8:45 am
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ahhhh balls, forgot bout the noggins. thats more timber needed then 🙂

i assume my only option for noggins is offsetting them to get the screws in yep as i did with the floor? and would i get away with just one set of noggins going across or will i need a couple of rows at a 3.4m span. i feel the answer is going to be 2 rows 🙂

 
Posted : 17/09/2016 10:27 am
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Forgot to check back with this... looking good!

On the polycarbonate subject - are you still planning on using it? If so I can take some pics of the canopy I completed last year - looks similar to that pic on the last page - using 25mm poly. In fact my entire build is spookily similar to yours in essence.

Pics if you want them - I can just send them in a email to save cluttering up your thread. I think I took a few of the build itself showing some fancy cross halving joins.

 
Posted : 17/09/2016 10:59 am
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i assume my only option for noggins is offsetting them to get the screws in yep as i did with the floor? and would i get away with just one set of noggins going across or will i need a couple of rows at a 3.4m span. i feel the answer is going to be 2 rows

You can offset them or skew the screws in at 45 degrees on half of them if you want them in line.

Noggins at the end of each sheet and one in the middle would be how I'd do it.

 
Posted : 17/09/2016 11:12 am
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You can get a torch on felt called tecnatorch. Goes on very easy. Used it a few times and had no problems.
Or you could use a edpm rubber roof.

 
Posted : 17/09/2016 11:20 am
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On the polycarbonate subject - are you still planning on using it? If so I can take some pics of the canopy I completed last year - looks similar to that pic on the last page - using 25mm poly. In fact my entire build is spookily similar to yours in essence.

Pics if you want them - I can just send them in a email to save cluttering up your thread. I think I took a few of the build itself showing some fancy cross halving joins.


thanks mate. id have liked to use that from a weight and looks perspective, but when i started pricing it up the cost started running away, so basically..... i just cant afford it :-/
id certainly like to see pics tho purely out of interest.

You can offset them or skew the screws in at 45 degrees on half of them if you want them in line.

ah ok, yep, 45 degrees may look better to keep em in line. i was going to say that surely [i]all[/i] the screws would have to be 45 degrees wouldnt they, but then thought you probably mean to screw in every other noggin first, then 45 degrees for intermediate noggins, yep?

Noggins at the end of each sheet and one in the middle would be how I'd do it.

thanks

You can get a torch on felt called tecnatorch. Goes on very easy. Used it a few times and had no problems.
Or you could use a edpm rubber roof.

looked at epdm and ruled it out on cost and i think the torch on stuff is also more expensive isnt it? budgets being stretched so far so need cost effective materials. thanks tho.

google google googling as usual and had another idea from stuff i saw for sale...... i assume instead of felt i cant use [url= https://www.roofingsuperstore.co.uk/product/black-jack-flashing-trade-100mm-x-10m.html ]this flashing tape[/url] on all the ply joins, and then paint [url= https://www.roofingsuperstore.co.uk/product/black-jack-fast-drying-roof-waterproofer-25-litres.html ]this waterproof coating paint[/url] over all the roof too? as i say, it doesnt matter too much what the top of the roof looks like, it slopes away from view and only the inside is visible. viable alternative or should i really just stick with the felt?

 
Posted : 17/09/2016 11:28 am
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ah ok, yep, 45 degrees may look better to keep em in line. i was going to say that surely all the screws would have to be 45 degrees wouldnt they, but then thought you probably mean to screw in every other noggin first, then 45 degrees for intermediate noggins, yep?

Yeah, that would do it.

 
Posted : 17/09/2016 11:39 am
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Don't use the paint. The wood will have a certain amount of movement in all weathers and I doubt the paint will move with it and would probably crack over time. Don't hold the felt overlap down with batons as this will just hold moisture and rot.
Do use 12mm external ply or above. Do use noggins but I'd space every 1.22m staggered.

 
Posted : 17/09/2016 11:53 pm
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Don't use the paint. The wood will have a certain amount of movement in all weathers and I doubt the paint will move with it and would probably crack over time. Don't hold the felt overlap down with batons as this will just hold moisture and rot.

advice noted and taken, thats why this thread exists 🙂 must admit i was kind of hoping someone would say yep, good idea if you cant see the finish but im not going to ask for advice and then not take it, ill use felt.
i wont use the batons then either.

Do use 12mm external ply or above.

im certainly not going to have my overall thickness any less than 12mm now, 12 is the figure ive come up with as a good compromise of strength and weight. can i just ask whether you mean [i]use 12mm ply only[/i] or [i]its ok to use 4mm ply and 8mm OSB[/i] please?
my mate has suggested that the ply/OSB combo would actually be stronger than just ply if all the edges of the two layers were staggered and overlapped, so top layer starting halfway along bottom layer. would you agree with that?

also i have 2 X 4.8m length bits of 2X2 left over so far so was looking at utilising them somewhere. my thoughts at present are to use 2X2 as noggins, save the cost of more 4X2 (joists will be 4X2). ok it means the noggins wont be flush with the joists but as long as they all look the same then am i right in thinking its no big deal? they are only there to stop the joists from bending arent they, which 2X2 will do fine?

Do use noggins but I'd space every 1.22m staggered.

ok, so thats noggins halfway along each 2.44 length, thanks, so 2 rows of noggins. can i ask why you state staggered please? yes staggered will be easier to screw in, but less aesthetically pleasing as theyll be on view. spose its no biggie but just wondering if theres a strength advantage.

thank you very much.

 
Posted : 18/09/2016 7:31 am
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Personally I'd stagger at 1m intervals and not worry about the join. Structural above asthaetics..
Staggered over 3 rafters so that you land on the join of the ply if your that bothered about looks but people will only look up once when they first visit and will tell you what a brilliant job you've done. After that they'll just get on with doing whatever under it..
Space your rafters at 305 centers over the large span if using 4x2. Put the crown upwards.
The noggins will be to stop the rafters twisting..2x2 won't cut it here
If you want to use the 2x2 up cut at 45deg and put in strategically placed braces in to resist side-loading from the wind.

 
Posted : 18/09/2016 8:01 am
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Space your rafters at 305 centers over the large span if using 4x2.

see this is where i may have to ignore advice unless theres a very good reason. 4 joists per width of ply, over 6 widths of ply, is an awful lot of wood/weight. im trying to get an acceptable compromise of strength to weight, as i mentioned before, im not totally happy about the weight of all that wood resting on basically the front and rear beams which are just screwed into the posts. the weight doesnt go down the big 4X4 posts, its on the ring beam itself.
i was thinking of 2 joists per 1220 width as a compromise, so centred every 610.

sorry, i dont understand the rest of your post as i cant imagine in my head what you mean.
staggered over 3 rafters and at 1m intervals? and i also dont know what the crown is. i apologise, youre being very helpful but i just dont understand 😳

EDIT: im also not sure what the diagonal bracing would bring to the party as im thinking the noggins would be resisting wind from the side? i dont spose you could find any google images of what you mean by any of the above could you so i can see it in my head?
thanks a lot 🙂

 
Posted : 18/09/2016 8:26 am
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If you were going to have 3 rafters per board the 1.22m ply joint would span 3 rafters.

Re Diagonal bracing..forget these if you're happy with how far you've sunk the corner posts. What size are they and how deep did you go?

How wide is the opening on the open part..you might need a knee-brace to help support the weight of the roof here..

If you're worried about weight on the ring put coach-bolts through.

[url= &imgrefurl=http%3A%2F%2Fwww.timberframediy.com%2Fchoosing-reference-faces-part-2%2F&docid=TzEPAHAmzZH8hM&tbnid=4wB9uLWN25rxrM%3A&w=800&h=618&bih=512&biw=360&ved=0ahUKEwiP66L68pjPAhXrIcAKHdsfDAYQMwghKAYwBg&iact=mrc&uact=8]crown up[/url]

 
Posted : 18/09/2016 12:19 pm
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Re side-/front-loading...sustained loading WILL cause movement...and although the noggins are in place you've only screwed into the end grain of the noggin which is the weakest connection you could make..don't think it will be as strong as a pegged tendon a la ' timber-frame '..overtime the structure could weaken. Any diagonal bracing reduces any movement significantly..
I must admit though I do tend to over-build..

 
Posted : 18/09/2016 12:27 pm
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How wide is the opening on the open part..you might need a knee-brace to help support the weight of the roof here.

the open end facing the field is 3.3m wide between posts. the full front of the gazebo facing the garden is 4.6m with the intermediate support post 2.3m so exactly halfway.
just googled knee brace and i can see how thatd work. i may well try and saw some 45 degree angles into a few bits of wood and do that. ive just started on the joists (2 rafters per 1.22m ply width so 610 spacing). and as you can see from below pic, i made a few support bits of wood that i thought would set the front off nicely. i reckon your knee brace suggestion may look better now tho 🙂 havent got any coach bolts right now so plopped some 4" screws in, but i plan on swapping for coach bolts, whether thats my chocks or your knee braces.

[img] [/img]

Re Diagonal bracing..forget these if you're happy with how far you've sunk the corner posts. What size are they and how deep did you go?

theyre 4x4 posts, the holes were around 18" for them but i probs used a couple of those inches with gravel for drainage. the 2 end posts (that would take the brunt of the winds from the field and cliff) i did with postcrete.

If you're worried about weight on the ring put coach-bolts through.

yup, thats my plan now.

re diagonal bracing, i dont really want any wood to go from corner to corner as that removes the access to it doesnt it? i just want it to look nice and open.

crown up

gotcha, thanks. id do that naturally anyway, but as it stands these joists seem pretty straight.

thanks a lot mate

 
Posted : 18/09/2016 1:03 pm
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By diagonal bracing I didn't mean corner to corner I meant knee-braces..my fault..
Good luck

 
Posted : 18/09/2016 2:18 pm
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thanks.

roof joists completed today. as mentioned before, theyre at 610 spacing so will support each end and halfway along each ply sheet too.
oh and colins guarding it protectively 🙂

[img] [/img]
need to do the noggins next, just need to know how to stagger them if you have any advice. at 3.3m depth, and joists halving each ply sheet, i was thinking first side do on the join and halfway, so from the front, set noggins at 4ft and 8ft (easier to work with imperial now as thats how the sheets are measured), then next joist do either just offset by the width of a 4x2, or..... do 4ft and 8ft from the rear as thats probably where the next sheet would be started from to stagger the sheets. that makes the noggins look a bit haphazard tho.

thoughts please?

EDIT: youll notice i also had to stagger the joists on the shed part, thats cos of the framework in the way of a full run, so i decided to do the front joists 'on the join' (as thats on view), and then inside the shed just off the join but i can muck about with extra noggins and whatnot for support in there, it doesnt matter how that looks.

 
Posted : 18/09/2016 5:35 pm
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Space the noggins at 610 also for a nice symmetrical pattern..start on the join ..
You should have a ply overhang front and back..

As for the shed part you can sister the rafters where they're staggerd..

 
Posted : 18/09/2016 8:58 pm
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Space the noggins at 610 also for a nice symmetrical pattern..start on the join ..

yup, can do that on the join on the first row (and third, fifth, seventh etc), but what about the 2nd/4th/6th etc where they need to be staggered in some way, so cant be on the join?

You should have a ply overhang front and back..

ooh wasnt planing overhanging the front, thought itd need to be flush for the felt to fold over neatly, and maybe a board of some sort screwed to front to finish off. i get the overhang at back, but why the front?

As for the shed part you can sister the rafters where they're staggerd..

had to google that, but yes, that makes sense, should have thought of that meself 🙂

thanks

 
Posted : 19/09/2016 6:39 am
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