Building a shed!!!

[Gary Cavie]

Well, not so much a shed, more a home from home! The walls will be studwork, with OSB on the outside, followed by paper & shiplap, filled with Kingspan / Celotex, then plasterboarded on the inside. Floor is to be concrete, insulated, then screeded. I'm fine with the planning once I start on the timber, but would like to seeke some opinions for the floor and base...

My plan is to lay a 6" concrete raft, with a membrane underneath, followed by a blockwork wall (one course). Inside will be the insulation, finally screeded over by 70mm or so. For the insulation, I have been looking at using Jabolite, but was wondering whether I would get acceptable results using large sheets of polystyrene. My in-laws get several 8x4 sheets of this a week in their business, which would save a bit on this stage. However, I'm not convinced that it would stand the load, without giving, and subsequently causing problems with the screed. Any ideas folks? The shed is only going to be used as a radio / electronics play area, with a small office setup, so no heavy equipment.

Secondly, ideas for heating. I've considered using electric underfloor heating, with a tiled floor, but not sure how good this will be as a primary source of heat. Another option is a small air conditioning unit (handy in summer & winter!). Whatever I go for, it has to be electric based, as the shed is a bit far down the garden to run a zone from the central heating system in the house!

Any suggestions gratefully received...

Gary

[Brian Reay]

Several new houses I've come across have a concrete floor, a plastic memebrane, sheets of 1" (or so) polystyrene, then 18mm t&g chipboard. If it stands the "load" in a house, I'd expect it to be OK in a radio shack, even with a few AR88s!

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73 Brian

[Gary Cavie]

It's not the radios that will be the problem - it's the weight of me in a swivel chair that will give the floor something to think about!

That's what I call a fast response BTW - have you got your modulator link sorted out yet to the car radio?

[John Rumm]

I think jablite basically *is* large sheets of polystyrene... I actually used it to insulate the walls of my workshop since it was way cheaper than I could get celotex or similar for at the time. e.c:

Secondly, ideas for heating. I've considered using electric underfloor

How big is the room space?

My workshop is about 8 x 12 ish and is well insulated (although it has a uninsulated suspended wood floor over concrete) and is easily heated by a small wall mounted fan heater that will do upto 2.2kW (but in reality lives on its 800W setting). Controlled via a separate room stat it will get the room to a comfortable temp in under 10 mins from "cold" (I never turn the heating off and leave the stat set to 5 degrees to keep things dew free).

[Adrian C]

Modulator link to the car radio? Arrgghhh!!! Hey, I expect 'hams' to be able to rip things apart to apply 'direct injection' AF techniques. Much better than doing it RF!!!

[Gary Cavie]

(Those 2 JB's above the CU - they aren't hidden & inaccessible are they?!)

Overall size is 5m x 4m externally, so about 4.5 x 3.5 internally, with

2.2m ceiling. Fan heater may well be an option, or even a kickspace one beneath one of the units (forgot to mention, it's also going to have a sink / worktop area!)

[sPoNiX]

Friend of mine had a murphy B40. Very heavy bit of kit which needed at least two people to lift:

[John Rumm]

You can unscrew the panel should you wish... (although since that would involve moving the workbench (or more difficult all the cr*p that resides under/on/near it I would be tempted to take a saw to it should I need access!)

I would have thought a few small fanheaters on thermostats would do the job easily enough and also save having any cold spots that might result with just one heat source. Perhaps a small oil filled rad might work for some background heat. You could always do some heatloss calcs for it if you want to get it "right". (I have always been surprised just how good the thermal performance of mine has been - especially since I did not use the best insulation in the first place).

[Christian McArdle]

Jablite actually is just a brand name for polystyrene.

An infrequently used shed should probably not have underfloor heating. Underfloor heating is excellent at providing background heat, but hopeless at heating a room rapidly when needed, which is likely to be the most efficient method of heating a shed.

I would recommend a thermostatic electric convector heater with selectable fan assist. This will rapidly bring the shed up to temp when needed, and can also be used for frost protection.

Christian.

[Gary Cavie]

I knew to my untrained eye it looked like polystyrene, but didn;t know if it was a denser, stronger version. Looks like a few quid saved!

My shed at present is not infrequently used - I spend too much time in it (2-3 hours per night, and several hours over a weekend!) I think I will go for the convector / fan approach - I use a 1250W convector in the current one, which isn't really enough - shed thermally very leaky, especially when the kids leave the bl**dy door wide open, as they've just done!!!

Thanks for the advice Christian.

[Christian McArdle]

With proper insulation and a closed door, a cheap standard 2.2kW electric fan convector will bring the shed up to temperature in a couple of minutes.

Christian.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember [e-mail] (sPoNiX) saying something like:

You can lift it yourself if you do it right.

I've got a B62 variant. Lovely bit of kit - made up to a quality rather than down to a price. A modern professional comms reciever costing many thousands can just about compete with it for sensitivity.

An old scrap metal man was telling me that in the late 50s/early 60s thousands of them were released from MoD stores and sold for scrap value; hardly surprising, there's a lot of ally in them.

[Brian Reay]

Hmm, new car so ripping it apart isn't a good option.

Basic idea is on hold, I'm still trying to find a way to mount the antenna really neatly so the car will fit in the garage.

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73 Brian

[Brian Reay]

"When I was a lad", a local army surplus dealer sold the crates that things like 19 sets were packed in and threw the 19 sets etc away- or sold them for

10 bob (50p), or 5 bob if he needed to shift them!

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73 Brian

[Brian Reay]

Well, I knew that but was too polite to say.

Still thinking on it. Main problem is the antenna mount- idea was to use a roof rack but the real Honda one is too high to allow the folded antenna to clear the garage door, the alternate rack didn't fit very well (I've just returned it).

I'm thinking on a home made bracket but need to make a cover that will mould around the fore-aft roof rail cover.

To get back OT for the group, any ideas on a moulding material I can form to shape then will "set", while remaining resistant to sun, rain, etc.

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73 Brian

[Gary Cavie]

Rapid Electronics used to have something in their education catalogue - aimed at CDT students, to allow them to make models. I can't remember what the change process was, but it could be moulded, then hardened. If the model was useless, then it could somehow be reverted back to the flexible state. It wasn't a complicated process IIRC, which probably rules it out for car / weather use! I don't have a Rapid catalogue to hand - hang on a moment...

Back again - scrap that idea, it's called liquid polymorph, and states that it is liquid at room temperatures, and sets solid at 2 degrees (sounds almost like water doesn't it?). Unless you plan to only have the car in freezing conditions (and after visiting you last year, that might not be so unlikely!!) it probably won't be a lot of use :-(

Gary