Register a SA Forums Account here!
JOINING THE SA FORUMS WILL REMOVE THIS BIG AD, THE ANNOYING UNDERLINED ADS, AND STUPID INTERSTITIAL ADS!!!

You can: log in, read the tech support FAQ, or request your lost password. This dumb message (and those ads) will appear on every screen until you register! Get rid of this crap by registering your own SA Forums Account and joining roughly 150,000 Goons, for the one-time price of $9.95! We charge money because it costs us money per month for bills, and since we don't believe in showing ads to our users, we try to make the money back through forum registrations.
 
  • Post
  • Reply
Jaded Burnout
Jul 10, 2004




cakesmith handyman posted:

Alrighty, I'm going to build my wife a garden office-type building because she needs the room to store and work on various crafts and activities, and lets face it who doesn't want their own private space? It'd be nice to get it out of the house too, as it's spread about various rooms.

WHAT: a timber-framed fully insulated and heated space, currently looking about 4.0x2.8m. Overall height under 2.5m. Needs to be secure/lockable, have a permanent electrical supply, weatherproof, not look like an abandoned shipping container.

WHERE: in the garden duh.
Option 1, the sunniest bit:

Pros, the sunniest bit, gets the sun from early afternoon to sunset
Cons, the sunniest bit, permanently filled with a box.

Option 2 not the sunniest bit:

Pros: far less intrusive into the most used part of the garden, still gets sun Sunrise to early afternoon
Cons: in shade early afternoon onwards, those trees the other side of the fence include sycamores, so we'll be pulling seedlings out of the roof until we die.

Option 2 it is.

WHY: Big question that, lets start with moving to a bigger house or extending this one are both not on the cards money-wise. I'd be looking min £30k to get an extension and I'm sure moving would end up costing a similar amount. Budget for this project is ideally £3k, honestly I'm expecting to go to £4, 4.5k. I'm not loaded so I'll be doing just about everything myself where legislation allows. We don't have a spare room that could be used instead.

Design:
Foundation
I'm planning to use ground screws because they'll cost about the same as pouring a pad, but are far far less effort and can be installed in about an afternoon regardless of weather.



You just screw these into the ground by hand (we have clay soil which is pretty good for this application) and bolt the joists to the included brackets. I'll need 9 or 12 of these at £30 each. They have a 0.43 tonne load rating each and you set the height by just winding them in and out a little until they're all level. Neat!

Frame
I originally wanted to build it from SIPS, which would have gone up quick and made a wonderfully warm building even with the minimum 100mm panels. I had to ditch this idea when compulsory delivery raised the price nearly 40% over the material cost. So I'll be timber framing it.
Walls 2x4, from outside to in: Cladding, probably board and batten, depends what comes up at an affordable price. Battens, breathable membrane, 9mm OSB sheathing, 2x4 frame with 75mm insulation, 9mm plasterboard.
Floor 2x6, three long ones bridging the rows of screws, shorter ones between those. Insulation again, 18mm OSB subflooring on top of that.
Roof 2x6, 2 long ones either long edge, 18mm OSB on top, insulation in the roof space. Flat roof design utilising pre-cut tapered firring strips to give the ~35mm over 2800 fall. Still undecided between EPDM rubber membrane roof or ECOPanel 30mm insulated sheets, which I understand in this case will just get glued straight onto the roof deck:


Services: I'll get mains power to this via trench, it'll have its own 20A panel inside with seperate light and power circuits. Enough to run a bunch of lights and a sewing machine etc. Hoping the Wifi stretches this far, else the router will get rehomed closer to this corner of the building.

Legality: As you may have guessed from the £s I'm in the UK, we have what's called permitted developments that don't need planning permission, basically it's under half the floor space of your home, under 2.5m tall if close to the boundary, no bed in it. Build it sensibly and safely and you're pretty much in the clear. My electrical cert is a few years out of date so I'll gen up on that and install everything in the cabin myself then pay for it to be inspected and connected.

After some discussion in the tooling thread I came to the conclusion DeWalt are liars for claiming their 18ga nailguns are for framing, and that the best tooling investment I could make would be to buy or borrow a small compressor, get an air framing nailer and sell it when I'm done. Estimated cost £100 plus nails but saves me hours in driving screws and nailed frames seem to be slightly stronger too. I can borrow a brad nailer for fixing panels to frames too. Same with a mitre saw for the hundreds of straight cuts needed. I think I have all the other tools I'll need, we'll see.

Artists impression: (doesn't include door, window, cladding)


I've never built anything this big before so I'm trying to work out everything in advance, I'll have a whole bunch of questions and I'm sure I've missed a whole lot already.
Oh and I've already been banned from calling it the Hormone Dome, so it's the Crafty Crab for now :v

Nice. I'll be watching with interest because eventually I'll be doing something similar.

Regarding the "no bed in it" rule, that's planning permission stuff for sure, but there's also related rules around building regulations that apply to something which *could* be used as accommodation, and being insulated is one of the qualifiers, I think. Worth checking on that one but IIRC the only result of that is you need to apply the fire safety rules which is perhaps not a bad thing.

Have you confirmed that it won't push you over the "outbuildings no more than 50% of plot excluding the 'original dwelling'" rule?

Adbot
ADBOT LOVES YOU

Jaded Burnout
Jul 10, 2004




cakesmith handyman posted:

I thought I had but I just realised I can't remember counting the garage into that. House is approx 7x10?m garage is 5x3m, this will be 4x2.8m, total 26.2m2 that leaves me 9 or 10m2 for shed and greenhouse, easily doable. Both shed and greenhouse are very cheap temporary ones so maybe when I finish this that'll be the next project.

I don't quite follow the maths here, but the sqm of the house itself doesn't matter unless you're starting from the total sqm of the plot.

The process is: (sqm of garden / 2) = amount of sqm you have to stick outbuildings on, where "garden" means "anything not-dwellinghouse when the dwellinghouse was built or 1978 if it was built before that" (might be wrong on the year there).

cakesmith handyman posted:

First questions: what do I do about breathable membrane under the floor structure? The membrane from the walls will get tucked and (stainless steel)stapled to the underside of the floor timbers, is the bottom of the floor just left open?

My house certainly is like that, in that if you pull up the underfloor on the ground floor you see dirt. I don't know what the recommended approach is for new stuff, though. I think there was a post in another thread about having your "crawlspace" be part of your house's general atmospheric bubble to reduce condensation on the underside of your floor joists.

cakesmith handyman posted:

Similar area: the bottom of the floor timbers will be about 50mm from ground level. What do I fill that gap with to stop leaves, critters and cold air blowing under without wicking moisture up to the frame?

Bricks, stone, or concrete, usually.

Jaded Burnout
Jul 10, 2004




Cool. How high off the ground will your DPC be?

Jaded Burnout
Jul 10, 2004




So, the reason that DPCs are minimum 150mm above ground level (rather than right at it) is to account for raindrop splashes, since splashing a bunch of water above the DPC would defeat its point.

An alternative is for whatever the wall is to be totally waterproof up to 150mm, which in some cases people do by rendering it or slapping bitumen on it or whatever. If the lift of your ground screws plus whatever height of 100% waterproofing your walls have is 150mm or more, you're good, otherwise you'll need to account for that.

Since it's timber framed I guess either a wrap, coating, or cladding at the bottom would be more appropriate than a DPC, if you need one at all.

Jaded Burnout
Jul 10, 2004




cakesmith handyman posted:

I can't find any mention of using breathable membrane under a suspended floor so sounds like the air gap does that job.

As long as you seal it around the perimeter, yeah, otherwise those gusties are gonna blow your heat away. In my inexperienced non-scientific opinion.

Tomarse posted:

I don’t think critters will spend much time under there if it is open; or you could just put mesh round it to keep them and leaves out.

The fox that lived under my shed back in London would disagree. Well, actually it would probably scream and steal bread, but that's a form of disagreement.

Jaded Burnout
Jul 10, 2004




Kaiser Schnitzel posted:

I don't know what the price difference between plywood sheathing and OSB is for you (here plywood is ~20% more), or your budget, but for a small project like this I would spend the little bit of extra money to use plywood vs OSB at least for the subfloor and roof and sheathing too if you can afford it. It will outlast OSB 3:1, especially if/when it gets wet.

What sort of plywood? I know marine plywood is rather expensive.

Jaded Burnout
Jul 10, 2004




Kaiser Schnitzel posted:

Exterior grade pine. It uses an exterior grade/water resistant glue, but not rot resistant core/veneers like marine grade. The pine plies will still rot with long term moisture exposure, but it doesn't turn to mush and swell up like OSB if it gets wet. The glue in OSB is sort of water resistant and it has a waxy coating on it so water beads off, but that is there to protect it if it gets rained on while the house is under construction, and doesn't really give any long term water resistance. Termites are a big problem here too and OSB seems to be their very favorite food. Here 3/4" OSB is ~$16/sheet and 3/4" exterior CDX pine is ~$20 sheet. Plywood is quite a bit stronger as well, but that's not as big a concern here.

Something like this?
https://www.alsfordtimber.com/sheet...0x18mm-elply18s

£25.80/sheet for 18mm "structural" plywood. OSB3 is £34.72, less for the (half-sheet) T&G version.

Jaded Burnout fucked around with this message at 14:41 on Oct 31, 2019

Jaded Burnout
Jul 10, 2004




Kaiser Schnitzel posted:

Yeah that looks like it assuming it has exterior grade glue. Surprised it is cheaper than OSB unless y’all have some kind of fancy Super-OSB over there.

It is OSB3, for what that's worth. Maybe the stuff you're seeing is OSB2? Or maybe we're just getting hosed on the price more for OSB than plywood.

https://en.wikipedia.org/wiki/Oriented_strand_board#Types

Jaded Burnout
Jul 10, 2004




cakesmith handyman posted:

Dumbass wood question: I've drawn everything up assuming 2*6 material is 38x138mm, gone to look for joist hangers and can't find many at 38mm, so I checked and the closest I can find for a treated 2x6 is tanelised 47*150mm. Am I looking at the right thing? I do need treated wood for this as it's outdoors right?

https://www.huwsgray.co.uk/shop/timber-sheet-materials/timber/sawn-treated-timber/sawn-tanalised-treated-timber-150-x-47-x-4800mm.html
https://www.huwsgray.co.uk/shop/building-materials/builders-metalwork/joist-hangers/st-timber-to-timber-joist-hanger-50mm-st50.html

38mm is 1.5". Even a planed-all-round 2x6 would be more like 45x145mm:
https://www.buildbase.co.uk/50x150-44x144-5th-premium-red-100008798-2825989

As to whether you *need* pressure treated, I mean I don't think it would hurt, particularly on your floor, but *technically* your studwork is inside once you have it boarded and wrapped.

Jaded Burnout
Jul 10, 2004




cakesmith handyman posted:

9mm plasterboard, 15 sheets, about £110ish

This will work, but I would recommend going thicker. I bought 9.5mm and I regret it, because it has quite a hollow knock to it and I'm worried I'm going to put my hand through it. In the future I'd buy more like 15mm.

cakesmith handyman posted:

EPDM for roof, 4.5x3m kit approx £150 inc adhesive

I foresee this being a godawful job to do, maybe one to farm out?

cakesmith handyman posted:

Cladding, I've no loving clue, probably a minimum of £500, could be double that. I can get away with something dirt cheap and ugly for the 2 sides you won't see, there's no point putting something pretty where it'll literally only be seen when I rake the leaves out every winter.

One of my neighbours (who is a carpenter) fitted some fairly simple lapped cladding to his outbuilding and I don't think it would be too expensive. Depends how shed-like you want it to be or not. If/when I do mine I'm eyeing up doing board-on-board or something like that, but that's only because I hate the look of lapped boards.

Jaded Burnout
Jul 10, 2004




cakesmith handyman posted:

Should power and ethernet be run in the same conduit? if it can be I'll do so, it's just the price of a roll of cable.

Depends on the cable. I wouldn't run regular 5e twisted pair alongside power, but shielded twisted pair is probably OK. I used shielded foil twisted pair so I didn't give a gently caress about interference, but it makes installation harder. Once you get into any sort of shielding you really need to ground one end or the other for it to be most effective, which means having the right sort of termination boxes and/or patch panels.

If/when I do this myself, my rough plan was to run power and data along separate shielded conduits but in the same trench, and to make sure they're armoured, one way or another. Digging into an ethernet line is annoying, digging into a power line is something else.

You could always run the cables through the conduit together on the surface so you can test the effects before you go to the trouble of burying it. Presumably you'd be able to pull a new cable if needed even after burying, since you'd have it loose in the conduit.

Jaded Burnout
Jul 10, 2004




Tomarse posted:

approx how many metres of ethernet cable do you need? I can probably sort you out to save you a few quid!

Hah good call. I've got most of a (500m) reel of cat 7a left over here. I'd be up for posting some if needed.

Jaded Burnout
Jul 10, 2004




cakesmith handyman posted:

Hopefully some unexciting pictures of slabs and a pile of wood to come soon.

Sweet beans. Do you want me to fix the grammar in the thread title?

Jaded Burnout
Jul 10, 2004




cakesmith handyman posted:

You're a good mod. Yes please, how long has it been bugging you?

Just since this latest bump, but I wouldn't want to overstep, I consider people's threads their personal property

Jaded Burnout
Jul 10, 2004




How are you feeling about using pavers for foundation?

Jaded Burnout
Jul 10, 2004




dog

Jaded Burnout
Jul 10, 2004




Start to finish construction of a garden office in the north of england:
https://www.youtube.com/watch?v=UWQqGBsqfI4

Jaded Burnout
Jul 10, 2004




Looking good.

May be too late for this now, but I've found one of these is hugely helpful for carrying full boards around solo.
https://www.amazon.co.uk/gp/product/B003CT4DAE/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Doesn't make setting them down flat any easier but at least you don't have to drag them about.

Jaded Burnout
Jul 10, 2004




Endie posted:

Totally agree. I bought one of those for shifting hundreds of sheets of plasterboard during my build, and it is unbelieveable how much better it makes the task.

For setting them down flat I worked out a routine with resting the board on the toe of my boot, slipping out the holder then letting them fall through ninety degrees (after the first one, which I placed). Far from breaking, they land on a cushion of air and usually actually slip along on it for an (annoying) inch or three before settling. Between walls and floors in the new storey and the new ceilings, stairwell framing etc downstairs we're talking round two hundred sheets with no damage.

That sort of aiming is OK-ish, yeah. I guess my main difficulty is when I need to set it down on a bunch of sawhorses.

Jaded Burnout
Jul 10, 2004




cakesmith handyman posted:

Roof height is going to be low in here

Well I can get you a little extra height right off the bat.

https://www.gov.uk/government/publications/permitted-development-rights-for-householders-technical-guidance posted:

“Height” - references to height (for example, the heights of the eaves on a house
extension) is the height measured from ground level. (Note, ground level is the surface of
the ground immediately adjacent to the building in question, and would not include any
addition laid on top of the ground such as decking. Where ground level is not uniform (for
example if the ground is sloping), then the ground level is the highest part of the surface of
the ground next to the building.)

So a) you should be measuring from the grass/soil level, not the underside of the concrete pads, and b) you should be measuring from the top of the slope, not the bottom.

Questions:
- is it too late to switch to a dual-pitched roof? I guess you're within 2m of the boundary.
- How do you feel about moving it to the side and digging the feet deeper? 150mm from the grass at the top of the slope to the DPC (which I assume you'll be putting on top of the floor you have now) is recommended, so you could reclaim the height of the feet and however much the pads protrude.

Concerns:
- 170mm is presumably the perpendicular thickness of the roof, so when you're at a slope it'll actually be a bit more than that straight up/down, so be careful about that.
- Also you seem to be marking your 2500mm at the back wall, but in fact the roof will continue upwards to the rear past that, so you'll be over 2500 as the drawing stands.
- Could you clarify where you're planning on putting the ceiling, and why you're losing so much height from that? Are you not plasterboarding the underside of the roof?

Jaded Burnout
Jul 10, 2004




cakesmith handyman posted:

My reading of that is it's measured directly adjacent to the building, not the top of the slightly higher eaves.

I don't think that's correct, but it's your place and all good if that's your understanding I haven't heard it from any living horse's mouth.

cakesmith handyman posted:

As it stands internal height will be approx 2017mm which is fine actually.

Yeah not too bad, that's how high my kitchen ceiling is. I think it's too low for me (my personal rubric is "can I touch the ceiling with both feet flat on the floor, if so it's too low"), but it's totally workable, even for a big space like that. In a smaller officey thing that you're sat down in most of the time I think it'd be all good.

Jaded Burnout
Jul 10, 2004




You can always get retroactive permission and it's probably going to be granted.

Jaded Burnout
Jul 10, 2004




cakesmith handyman posted:

You are now entering the third dimension!

:O

Jaded Burnout
Jul 10, 2004




Wickes do better quality doors than B&Q, though I think they're all fairly limited on the amount you can cut them down due to their construction. Most I've seen is 20mm.

Edit: though now I'm thinking about it, all my experience of non-custom doors is for internal doors, so ignore me

Jaded Burnout
Jul 10, 2004




cakesmith handyman posted:

No it's a fair criticism, Wickes are better. 25mm each side/end is at the limit of what most door manufacturers allow for trimming, I don't think I'm up to building my own door so...

Hmm.

I've had a look at my local timber merchant and they have doors like this:
https://www.alsfordtimber.com/doors...8x44mm-col33-44
and like this if you don't care that it's basically a garden gate:
https://www.alsfordtimber.com/doors-windows-joinery/external-doors/softwood-doors/flb27-frame-ledge-braced-external-gate-6-6-x-2-3-fsc-16411

They're listed at 1981, is your 2050 from the height of a door itself, or does that include lining?

I know you said you'd looked into custom doors, but if there's a timber merchant near you they might have something suitable and can tell you if it's constructed in a way to allow more trim than you might get from a B&Q or a Wickes door. They might even be able to modify one of their stock doors for you.

Worst case scenario I could maybe make you one on the cheap, though shipping probably not fun. Where-ish are you located?

Jaded Burnout fucked around with this message at 13:19 on Aug 10, 2020

Jaded Burnout
Jul 10, 2004




Makes sense.

Jaded Burnout
Jul 10, 2004




Rad!

Jaded Burnout
Jul 10, 2004




It's funny how cozy it starts to feel once the wall sheeting is up.

Jaded Burnout
Jul 10, 2004




EPDM seems like a good choice though. I've got fibreglass and no sealants will stick to it.

Jaded Burnout
Jul 10, 2004




Based on the cost of my cladding I'm going to guess at least £500 for the wood alone. Bear in mind all these photos you see of lovely golden cladding are taken 2 weeks after they're fitted. They only stay that way for about 6 months.

Jaded Burnout
Jul 10, 2004




cakesmith handyman posted:

I just wish I didn't feel so thoroughly fatigued for no good reason.

Jaded Burnout
Jul 10, 2004




This project is a wonderful guide to what things I'm best off not doing myself. Thank you for your sacrifice.

Jaded Burnout
Jul 10, 2004




cakesmith handyman posted:

Went browsing cushion floor/lino. My suggestions were not appreciated.


I especially love that the OSB finish would be worse than what's there now. I'm a little baffled why anyone would want that tbh.

cakesmith handyman posted:

Unfortunately the guy I used to use a few years ago isn't answering his phone and I've resorted to contacting anyone in the village Facebook group who recently asked about electricians and seeing who they used and if they recommend them. We'll see, don't want to do much else in there until I've had quotes incase I have to pull something down again.

I've had reasonable luck with checkatrade.com if that's useful in your area.

Adbot
ADBOT LOVES YOU

Jaded Burnout
Jul 10, 2004




You don't bead inside corners, you tape them. You bead outside corners, basically anywhere where you want the plaster to stop at a sharp line in mid air, you need the bead to plaster up to.

You don't often get outside corners between walls and ceilings, presumably why you're not seeing anything about it.

  • 1
  • 2
  • 3
  • 4
  • 5
  • Post
  • Reply