Shed build - help

listermint · 04-09-2018 10:04am

The orcan is not for that purpose it's actually for the tape itself.its primary purpose is between wall and tape to create additional adhesion on uneven surfaces. You used it in a gap filler capacity which it's not intended for and of course would have used tonnes.

Gap filler is more appropriate for what you wanted there and tap to seal. I wouldn't waste any more money using orcan as a gap filler

Lumen · 04-09-2018 12:27pm

listermint wrote: »

The orcan is not for that purpose it's actually for the tape itself.its primary purpose is between wall and tape to create additional adhesion on uneven surfaces. You used it in a gap filler capacity which it's not intended for and of course would have used tonnes.

Gap filler is more appropriate for what you wanted there and tap to seal. I wouldn't waste any more money using orcan as a gap filler

Thanks, I realise it's not the primary use of it but I figured it has the advantage of a guaranteed long life and is super sticky and flexible.

What's products are suitable for permanent air tightness sealing of small gaps in building fabric? I think I've read that ordinary silicone sealant degrades after a time.

listermint · 04-09-2018 2:09pm

Lumen wrote: »

Thanks, I realise it's not the primary use of it but I figured it has the advantage of a guaranteed long life and is super sticky and flexible.

What's products are suitable for permanent air tightness sealing of small gaps in building fabric? I think I've read that ordinary silicone sealant degrades after a time.

The tape is performing that job, Stick with it.

You can close the gap with simple window foam gap sealant, (window one because it doesnt expand rapidly)

But the tape is performing the job of air tightness thats its job.

Lumen · 06-09-2018 11:44am

I discovered some unevenness whilst attempting to lay the second layer of OSB. I'm not sure whether the joists were crowned or I'd caught some insulation between the joists and the OSB, but since I'd stupidly glued the bloody tape on there was no way I was going to pull the floor up to diagnose it. (Aside: the only way I could find to to remove glued Tescon tape is using the edge of an random orbital sander, moving it along the seam at a speed of about 1mm a second. I did a short section, cursed a lot and then re-taped it).

So I laid some 4mm woodfibre panels on top of the first layer, left out a row over the raised joist, and put the second layer of OSB down over the top. Couple of hundred more decking screws and now it's done!

The door position has been bothering me. It seems so arbitrary. At the side of the gable end, off the raised platform? Something is wrong here.

So I'm going to switch the front gable from a single king post design to a pair of queen posts, and put the door underneath. This also enables me to raise the door height to a comfortable 2m, and put some diagonal bracing in the stud wall.

And it looks better.

Anyway, I effectively now have an empty wooden paddling pool. It's raining and I'm trying not to think what happens to all that OSB and woodfibre if my tarp fails, so I'd better get on with it.

Lumen · 06-09-2018 11:58am

Oh, I was a bit worried about load bearing on the king/queen posts until I watched this.

Wood is strong.

https://www.youtube.com/watch?v=cEUgNjT1nGU&t=1490

listermint · 06-09-2018 3:45pm

Lumen wrote: »

Oh, I was a bit worried about load bearing on the king/queen posts until I watched this.

Wood is strong.

https://www.youtube.com/watch?v=cEUgNjT1nGU&t=1490

Newgrange and the Pyramids strong

Trasna1 · 06-09-2018 11:15pm

I can see why you went for a king/queen post construction for the roof, but it will be quite unstable when it's being erected. That king post frame, unless it has engineered joints will not offer much lateral stability. The design shown won't actually be stable until it's fully sheeted out, so that is something to be mindful of.

An alternative way of doing the roof would be to have your structural members at the top of the wall panels and have the roof propped off that, somewhat like a ring beam. Granted these beams would be big as they'd have to control the thrust of the roof too - but a couple of ties would bring it back to a manageable size (if it were an option available - work them into the mezzanine design?).

I'd put braced bays in the long wall panels too, instead of just depending on the diaphragm action of the ply sheeting.

Rows Grower · 06-09-2018 11:32pm

Lumen wrote: »

Not sure yet. Maybe just really big screws.

Nope, I'll probably just run it along the boundary hedge. Have a load of 6" perforated pipe left over from fixing drainage elsewhere.

But, but.....................................

Lumen · 07-09-2018 9:56am

Trasna1 wrote: »

I can see why you went for a king/queen post construction for the roof, but it will be quite unstable when it's being erected. That king post frame, unless it has engineered joints will not offer much lateral stability. The design shown won't actually be stable until it's fully sheeted out, so that is something to be mindful of.

Indeed. The way I've seen it done on Youtube is to nail sway braces between the frame and deck (or in my case ring beam) until they're fully braced and sheeted.

I haven't quite worked out the order of construction yet. In order to prevent the OSB getting rained on I need to get the rafters in place so I can at least drape a tarp over the top.

So I guess I'll frame the long through walls on the flat, raise and brace them, then frame the gables between them, raise those with posts in place, fix the overlapping top plates, pop the ridge beam on, then rafters, then OSB over the rafters, then insulation over OSB, detailing in the membrane over the edge of the first row of roof insulation.

At that point I'll have a rainproof roof (the roof insulation will do three months of exposure) and curtains of membrane down the sides, prob polythene stapled to the gables, so it'll be mostly weatherproof. I can then sheet, insulate and batten the the outside of the frame at my leisure.

Trasna1 wrote: »

I'd put braced bays in the long wall panels too, instead of just depending on the diaphragm action of the ply sheeting.

I think I can do that in the corner studs where I'm not going to want windows or recessed shelving. I'll probably turn them 90 degrees and cross them in an "X".

Trasna1 wrote: »

An alternative way of doing the roof would be to have your structural members at the top of the wall panels and have the roof propped off that, somewhat like a ring beam. Granted these beams would be big as they'd have to control the thrust of the roof too - but a couple of ties would bring it back to a manageable size (if it were an option available - work them into the mezzanine design?).

There won't be any outward roof thrust, all the static load is down. That's what the ridge beam is for.

As I understand it, in a conventional ridge board design the ridge is held up by the rafters, and the collar ties prevent the walls from spreading.

In a ridge beam design, the top of the rafters are held up by the end posts (via the ridge beam), so there is no outward force on the walls.

A ridge board design is stronger and more efficient, and works on large spans. The ridge beam design requires very deep timber (or a steel beam) and won't work on large spans. Fortunately I have only 4.7m longitudinal span, and by my calculations I should only get something like 7mm ridge beam deflection at the middle of the 300mm (D) x 150mm (H) beam (the L/360 standard would allow 13mm of deflection).

Lumen · 07-09-2018 9:59am

Rows Grower wrote: »

But, but.....................................

What?

Rows Grower · 07-09-2018 10:27am

Lumen wrote: »

What?

Leftover materials lying around to be used?

This reminds me of my shed building tactics.

Get back on track here now, dam the expense and throw money around like it's burning a hole in your pocket.

Trasna1 · 07-09-2018 1:29pm

If

Lumen wrote: »

Indeed. The way I've seen it done on Youtube is to nail sway braces between the frame and deck (or in my case ring beam) until they're fully braced and sheeted.

I haven't quite worked out the order of construction yet. In order to prevent the OSB getting rained on I need to get the rafters in place so I can at least drape a tarp over the top.

So I guess I'll frame the long through walls on the flat, raise and brace them, then frame the gables between them, raise those with posts in place, fix the overlapping top plates, pop the ridge beam on, then rafters, then OSB over the rafters, then insulation over OSB, detailing in the membrane over the edge of the first row of roof insulation.

At that point I'll have a rainproof roof (the roof insulation will do three months of exposure) and curtains of membrane down the sides, prob polythene stapled to the gables, so it'll be mostly weatherproof. I can then sheet, insulate and batten the the outside of the frame at my leisure.

I think I can do that in the corner studs where I'm not going to want windows or recessed shelving. I'll probably turn them 90 degrees and cross them in an "X".

There won't be any outward roof thrust, all the static load is down. That's what the ridge beam is for.

As I understand it, in a conventional ridge board design the ridge is held up by the rafters, and the collar ties prevent the walls from spreading.

In a ridge beam design, the top of the rafters are held up by the end posts (via the ridge beam), so there is no outward force on the walls.

A ridge board design is stronger and more efficient, and works on large spans. The ridge beam design requires very deep timber (or a steel beam) and won't work on large spans. Fortunately I have only 4.7m longitudinal span, and by my calculations I should only get something like 7mm ridge beam deflection at the middle of the 300mm (D) x 150mm (H) beam (the L/360 standard would allow 13mm of deflection).

I think you might have misunderstood what I was getting at. I can see why you went for the design you did in that there is indeed no outward thrust from your design of the roof. The alternative I suggested does have an outward thrust and is somewhat more structurally complex but that can be overcome with a sufficiently strong beam at the top of the longitudinal walls (or by using ties). My suggestion is more structurally inefficient (unless you use ties) but the advantage is that you and do most of the structural work on the ground and avoid having to lift a 4.75 * 0.3 * 0.15 C24 timber beam over your head (which will be not far off 100kg) onto the tops of the posts. You might need to think of lifting the two halves of the double 300x75 separately and bolting together in place and/or having help with the lift. It's the trickiest bit you have left to do (along with how you'll connect it to the posts), and is well worth having a good idea in your head how you are going to go about it.

I'm not being critical here btw, it's clear your put tons of thought into your design and just as there are many ways to skin a cat, there are as many ways to erect a shed.

Keep us updated, I love a good shed!

Lumen · 07-09-2018 2:25pm

Trasna1 wrote: »

My suggestion is more structurally inefficient (unless you use ties) but the advantage is that you and do most of the structural work on the ground and avoid having to lift a 4.75 * 0.3 * 0.15 C24 timber beam over your head (which will be not far off 100kg) onto the tops of the posts. You might need to think of lifting the two halves of the double 300x75 separately and bolting together in place and/or having help with the lift. It's the trickiest bit you have left to do (along with how you'll connect it to the posts), and is well worth having a good idea in your head how you are going to go about it.

Aha! OK.

I thought that would hard too, until I discovered the idea of ladder jacks.

https://www.youtube.com/watch?v=tlOhNdz0T9I

Lumen · 12-09-2018 8:49pm

Bit more progress today.

Built/assembled a mitre station. Played with my new track saw. Dithered over wall height. Cut some studs and plates. Banged in some nails. Raised the first wall.

Started on the second wall but due to it being after 5pm it was a bit rushed and crap so I'll have to sort that out in the morning.

https://imgur.com/a/6xYzFtp

listermint · 13-09-2018 7:07am

There's no pictures of the track saw. :P

Lumen · 13-09-2018 7:58am

listermint wrote: »

There's no pictures of the track saw. :P

Not sure if serious.

The track saw is like a portable table saw, without the serious injury risk. Mark a couple of points, plonk the track over them lining up to the rubber edge, drop the saw on and buzz it.

I might actually do the rest of the studs with it.

listermint · 13-09-2018 11:40am

Lumen wrote: »

Not sure if serious.

The track saw is like a portable table saw, without the serious injury risk. Mark a couple of points, plonk the track over them lining up to the rubber edge, drop the saw on and buzz it.

I might actually do the rest of the studs with it.

Oh i know what a track saw is, just wanted to see which one you had.

was close to pulling trigger on a festool last year. Still might

Lumen · 13-09-2018 1:48pm

listermint wrote: »

Oh i know what a track saw is

Sorry, am trying to write these posts for people as ignorant as I am.

Lumen · 13-09-2018 9:18pm

Fixed and raised the second side wall. Glue-laminated a king post. Framed the back wall. Collected the chunky door header. Made some rafter templates.

Goodnight Elizabeth.
Goodnight John Boy.
Goodnight Shed.
GOODNIGHT SHED.
<barely audible rustling of polythene sheeting>

Steve · 13-09-2018 9:25pm

I feel your pain with trying to keep the rain out.

3 years ago I started my shed this time of year and no sooner was the timber delivered, it pi$$ed rain every day for 3 months.

Try keep it dry, it will swell more than you think and when it dries again and settles to a 'normal' state then cracks can appear.

listermint · 13-09-2018 9:27pm

Frustration and satisfaction in equal measure I'm sure.

Solid work!

Lumen · 13-09-2018 9:36pm

Steve wrote: »

I feel your pain with trying to keep the rain out.

3 years ago I started my shed this time of year and no sooner was the timber delivered, it pi$$ed rain every day for 3 months.

Try keep it dry, it will swell more than you think and when it dries again and settles to a 'normal' state then cracks can appear.

The framing timber has been under cover before and during the build but would be fine with a bit of rain, however the constant fear of getting the OSB and woodfibre/hemp floor wet is slightly wearing.

I'm been quite lucky with the weather so far, but looking forward to getting a proper roof on it!

I was down at MDS/woodcomponents.ie today picking up the header and had a look at their collection of cladding profiles. All quite impressive. I think I'm going for "rainscreen profile" Siberian larch cladding on the walls and cedar shingles for the roof rather than slate. They also do bevelled battens which will be handy to prolong the life of the horizontal elements of the cladding support.

Rows Grower · 13-09-2018 9:38pm

Good night John Boy.

Steve · 13-09-2018 9:50pm

Lumen wrote: »

The framing timber has been under cover before and during the build but would be fine with a bit of rain, however the constant fear of getting the OSB and woodfibre/hemp floor wet is slightly wearing.

I'm been quite lucky with the weather so far, but looking forward to getting a proper roof on it!

I was down at MDS/woodcomponents.ie today picking up the header and had a look at their collection of cladding profiles. All quite impressive. I think I'm going for "rainscreen profile" Siberian larch cladding on the walls and cedar shingles for the roof rather than slate. They also do bevelled battens which will be handy to prolong the life of the horizontal elements of the cladding support.

I'll see if I can dig up some pics.

I used 18mm t&g covered in an underlay covered in bitumen shingle tiles.

https://www.youtube.com/watch?v=FgPiqizf_Eg

Beneath that, I have 50mm hard rockwool insulation, 20mm foil covered pipe insulation roll sealed on the seams and 6mm decorative t&g on the inside. Have had no condensation or issues in the last 3 years.

penno · 14-09-2018 1:32am

Love this thread xx

Lumen · 14-09-2018 9:07pm

Cut the king post in a hurry as I'd persuaded wife to help raise the wall before going to work. 47mm too short, forgot about the second top plate. Fffff. Raised the back wall anyway. Nailed, fiddled and fettled until everything was straight.

Glued an extra slice to the king post. Glue joints are stronger than wood, right? Newgrange, pyramids, etc. Be grand.

Tidied up.

Planed the queen posts and headers for the front wall.

I've inset the king post from the studs 25mm so that even if I add internal cladding, I'll still be able to see the "post and beam" structure. Looks nice. Will do the same for the front wall.

https://imgur.com/a/05ExnXK

Zebbedee · 15-09-2018 8:39am

Lumen wrote: »

Goodnight Elizabeth.
Goodnight John Boy.
Goodnight Shed.
GOODNIGHT SHED.
<barely audible rustling of polythene sheeting>

Noting with interest that this project is no longer inanimate.
It lives... It breathes...

You don't think perhaps you've become a tad 'obsessed' with it?

Lumen · 15-09-2018 2:26pm

Obsession is necessary!

Fourth wall!

20180915_141344.jpg?dl=1

Zebbedee · 15-09-2018 10:43pm

Lumen wrote: »

Obsession is necessary!

Fourth wall!

It's certainly driving this project forward.
Well done, keep it up!

Lumen · 16-09-2018 12:43pm

Spent all morning fixing problems from yesterday's wall raising. The biggest problem was that there was a ~2mm gap between the top of one queen post/door jamb and the header, and it would be bothering me until the end of time, so after arsing around with a power plane and hitting it repeatedly with various hammers, I eventually just ripped and replaced the stud. Which is quite tricky when it's nailed up through a bottom plate, two top plates and attached to a queen post.

This is how it goes, two steps forward, one step back...

Anyway, gaps and wall straightness are all good now, more or less....

Lumen · 16-09-2018 11:14pm

Well that went better than expected.

Installed the overshooting second top plate, glued and screwed the minor king post, raised the two beam members to just below their final position ready for gluing and bolting together in place, walked the wall to cut a few overhanging branches, tarped and sheeted the exterior ready for the rain.

I'm glad I used nice chunky TR26 (47 x 147) studs cos there was a lot of load on them during the beam raising.

Will take a few days off to catch up on work.

prosaic · 17-09-2018 2:33pm

The tent will get tested over the next 24 hours.

Lumen · 17-09-2018 3:40pm

prosaic wrote: »

The tent will get tested over the next 24 hours.

Yeah. I was thinking about this over lunch. Which is painful, cos Shed and I are supposed to be on a break.

The beam is currently not very secure. I mean, it's fine with gravity, but it's just sitting there in two pieces held together with some straps. And there are no rafters. And Baunativ screwed up dispatch of my massive Spax order, so the front queen post/header arrangement is held together with a couple of deck screws.

What it needs is to be raised, glued, bolted and braced with four rafters.

But I'm not sure I can be bothered. Everything hurts.

Be grand.

I just need to make sure the wind can blow through and then cover the floor with cotton painting sheets for any driven rain.

slavetothegrind · 17-09-2018 6:39pm

fingers crossed weather won't be too bad!

Enjoying thread thanks!

17-09-2018 6:52pm

A couple of rolls of duct tape could be a worthwhile purchase if you have time. Tape up the edges of your tarps.

prosaic · 19-09-2018 10:37pm

Hope it all held up ok

slavetothegrind · 19-09-2018 11:41pm

hope so too, i had a tree down. No damage luckily.

Lumen · 20-09-2018 9:36am

It's still standing, yeah, yeah, yeah. :pac:

Lumen · 20-09-2018 9:38am

One corner of the floor did get wet when an unsecured corner of the roof tarp folded back in the wind, but it seems to have dried out since. That's what I get for tarping in the dark.

prosaic · 21-09-2018 9:24pm

Sail on to calmer waters!

Lumen · 24-09-2018 8:51pm

A steady day today after a bit of a break.

Raised the two-piece beam to its final position. Decided not to bother gluing it, coach screws in the gaps between the rafters will do. Put a couple of big Spax screws into each end. Nobody died.

Cut and attached about 8 rafters. Slow work. Slight differences in ridge-stud distance, maybe 5-10mm over the length of the shed, mean that each rafter needs to be individually trimmed to satisfactorily close all the gaps.

The structural ridge beam combined with a vaulted ceiling in which I want no visible fixings makes rafter-beam attachment tricky. I ended up fixing the lower end with a 200mm Spax screw and a 6 inch nail, and then the upper end with a counterbored 180mm M10 stainless coach screw. Normal screws don't do well in shear, and nails can bend, so whilst the coach screws are a bit of work the result feels very strong. I'm somewhat hedging my bets by using three types of fastener.

The counterboring is normally neater but this is at a funny angle and will be covered by OSB anyway.

https://imgur.com/a/Q4RSPEU

my3cents · 24-09-2018 9:01pm

Ever tried a Kregg Jig? Hd version - https://www.amazon.co.uk/Kreg-305380-Jig-HD-KJHD/dp/B00TWWCGDQ.

Lumen · 24-09-2018 9:03pm

my3cents wrote: »

Ever tried https://www.amazon.co.uk/Kreg-305380-Jig-HD-KJHD/dp/B00TWWCGDQ ?

I have a straight jig but not one of those pocket hole things. I wasn't sure which range of angles they did.

So I made up my own jig out of a bit of scrap, works well enough.

my3cents · 24-09-2018 9:16pm

Lumen wrote: »

I have a straight jig but not one of those pocket hole things. I wasn't sure which range of angles they did.

So I made up my own jig out of a bit of scrap, works well enough.

The kregg system is ridiculously expensive but it does work. The HD one is handy for wall framing. The smaller jigs are adjustable for the thickness of the timber the HD one if for timber thats at least an inch and a half thick.

listermint · 24-09-2018 9:51pm

my3cents wrote: »

Ever tried a Kregg Jig? Hd version - https://www.amazon.co.uk/Kreg-305380-Jig-HD-KJHD/dp/B00TWWCGDQ.

Have a kregg, love it.

Lumen · 30-09-2018 8:53pm

Rafters finished. Bit of a PITA, massive time suck. Whereas on the rest of the framing 1mm or so either way is unnoticeable, on the rafter cuts the slightest gap looks awful, and each rafter needed to be ever so slightly different from the one before due to accumulation of previous tiny errors, twists in the timber or the flapping of a butterfly's wings in Beijing.

I switched back and forth between the mitre and the plunge saw, and was never very confident with either. So if I never see another rafter it'll be too soon.

Also got a few sheets of OSB up on the roof, fun easy job. Am painting them first with vapour permeable clay paint as they'll be exposed on the inside. No pics as it was dark when I stopped. Again!

Getting there...

Zebbedee · 01-10-2018 9:41am

Well done.
That's the hard bit over with.
On to the fun and fast end of it now.

Lumen · 04-10-2018 8:11pm

Nearly finished the sheeting. Just the front wall and the top of the back gable to do. It's been easy but time consuming.

Paint, cut, clamp, screw, tape, repeat.

I have a workshop, temporarily.

A couple of visible joins (5mm expansion gaps) in the painted OSB along the roof. What to fill with? Tec 7?

Need to buy the rest of the insulation now. Road trip!

I might put fixed glazing all across this wall, behind the studs. Maybe a narrow door. Later though, need to get it winterproofed first.

Rows Grower · 04-10-2018 8:43pm

Looks majestic, fair play Lumen.

Lumen · 11-10-2018 6:33pm

So, another week on. Where does the time go? EVERYWHERE!

I finished the sheeting, taped it all up, fiddled around, then started the insulation.

It's nice stuff to work with this woodfibre board. After I had the first wall up I thought I'd better read the writing on the side that says...squint...."outside". Ah right, so that bottom layer is the wrong way round. Does it matter? No idea. Do it again!

Underestimated the amount of insulation I needed so I cut some T&G into the offcuts by hand.

The membrane was tricky to get right on my own, and then I had to figure out how to hit the centre of each of 18 studs blind with a screw through ~130mm of batten, membrane, insulation and OSB. Laser measuring thing came in handy for that. Only missed one!

Seriously though, the time goes so fast. Each layer of each wall seems to take a day. And there are a lot of layers.

Anyway, both side walls are done so with the tarp on top the rain isn't causing any problems.

It'll be all over by Christmas!

Hand-cut tongue

Bevelled edges to go under the roof

How to position 5x3m of flappy membrane on a wall solo with no fixings? I'm still not sure how I managed that.

Battens just have one screw each, to allow fettling

These will be cut and mitred later

Membrane trimmed around cantilevered joists protrusions

....and this is what it looks like now, except I've tidied up the front a bit since this pic, removing those sticky out bits at the top corners

Shed build - help

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