[TheGreenMachine]

I'm now at the stage where I'm ready to start insulating and lining out my new man cave but I thought I'd ask for a bit of advice / input before I get too carried away. Hopefully someone knows more about insulating than I do and can point me in the right direction.

 

So my build is made from Shiplap timber 16mm all round with 14mm roof and i'm looking to insulate it sufficiently to use as a workshop and for chilling out etc. It's going to house electronics and test equipment, a computer, some machinery such as 3D printer, CNC Router etc. I've been reading up on the subject of insulating sheds for ages but I'm not 100% sure (so much conflicting info out there) so I thought I'd run my idea past you guys here and see what you think.

 

How I plan on Insulating the Shed:

 

1. Line the inside of the shed first in Vapour Barrier secured against the shiplap (what I call the cold side).
2. Fit spacer battons over vapour barrier in the cavities to create a small air gap between the vapour barrier and the insulation material when it's fitted in.
3. Fill the cavities with 100mm Mineral Fibre (loft) insulation.
4. Line all the walls with Damp Proof Membrane across all the insulation, battons etc to completely seal the shed.
5. Board over the whole lot with 12mm OSB3 or Moisture Resistent MDF
6. The same applies to the roof as above.
7. Install free floating floor lined first with DPM and then with kingspan and overboard.

 

Climate Controlling the Inside:

 

I was originally planning on having a small wood burning stove in the shed in one corner as a cheaper source of heat but then I read about condensation, insulation, cold spots, dew points, air circulation, moisture control and it threw my head into a spin so I scrapped the idea of a wood burning stove and opted for this idea instead.

 

Basically, I've read that in order for the insulation to work how it should I need to climate control the room to ensure the cold point of the shed is not inside or in the insulation so moisture condenses and the thing rots from the inside out.

This means installing air circulating fans to pull in new air and take out the old. If I do that I can't have a wood burning stove as it risks pulling monoxide inside so I've had to opt for Oil radiators instead. I thought about fitting one Oil Rad to each gable end as it's a rather large build. 20ft long by 8ft deep. I'll also be installing a dehumidifier as well just to be doubly sure. I plan on having everything work from one controller to keep the room at a set temp and a set humidity level if possible though I've not gotten that far yet.

 

My main concern is that I'm doing everything correct which I think I am but I'm not 100% sure. People have got this wrong and they've ended up with damp spots, mould growing inside the insulation, the shed rotting from the inside out etc.

 

I really don't fully understand the complex science of insulation, heat transfer etc etc etc. I get the fact that cold damp air condenses on a warm surface and that I don't want that to occur inside the shed except where it's supposed to but I really don't get it 100%. There's so much to take into account like how many people in the building, how often it's used, what it's used for, when it's used, where it's built... So much it's mind boggling.

I just thought it was a case of whack the insulation in and get on with it but it's not. Some time spent thinking about this before I get too carried away can save me from having my shed rot away in 5 years time LOL

 

If anyone knows anything about this stuff, I'd appreciate some input


Thanks

 

 

 

 

Edited by TheGreenMachine, 30 September 2016 - 08:17 AM.

[duke]

hi green when i used to grow large scale i had 2 purpose built sheds first thing i done was collect up lots of good quality pallets which we used to mount the sheds on so we could use very discreet inlet vents via the floor and also keeps wood from rotting also acted as drain for emtying res etc easy,then gloss paint all the wood inside and out (plywood built)and use top quality marine ply atleast for the roof and floor,then i just lined all the walls and roof with kingspan and fitted aircon and a couple of oil rads it lasted over 7 years and was still in good condition when we left so must have been good build,im convinced good gloss paint is better than wood preserver for longevity the cavity can be filled but not crucial as the air gap imo helps also to avoid trapped pockets of moisture,tbh unless the shed is well shaded (mine was under a massive oak tree) you really need ac for the summer or have to use only low wattage lights,maybe leds? i still miss my sheds tbh and was gutted leaving them behind so good luck i shall follow along,peace

[Chew]

I would ditch the mineral fibre and use foiled Kingspan/Celotex all the way.

 

Look at Seconds and Co. You can get some good deals there.

[captain beefheart]

kingspan

[The Dude Abides]

Yeah, gotta agree with Chew and Cap, no need for a vapour barrier either as both are totally waterproof.

 

All good things

 TDA

[weedtroll]

Yeah kingspan will do most what you need but Duke's advice about lifting up the shed off the floor is imho number 1.

 

Always have wooden buildings on footings and never directly on the ground as wood will draw up moisture, treated or not.

Treating wood with anything from gloss paint to wood stains works better if you can heat up both the wood and the paint/stain.

You want the wood to "drink" in as much paint as possible.

 

I like to soak anything used in the floor and lower walls in Pine tar (using heat again) makes it highly water resistant and virtually rot proof.

[TheGreenMachine]

Hey guys!

Thanks for the responses.

 

I can confirm the shed is off the ground. It's stood on top of dense concrete blocks (40 total) spanning the entire floor. The blocks are laid face down and have been placed at 2ft intervals on every joist. This has raised the shed up off the slabs by about 4 inches giving a nice air gap. At first I was just going to build it directly on the slabbed base but last minute I decided to sit it on blocks as well so air could flow properly. I also had to jack up the small shed at the rear and stand that on blocks too else they wouldn't have lined up when connected. The underside of the base / floor was treated with 3 coats of wood preserve prior to assembly along with the all exterior walls.

 

I did look at kingspan including the second hand stuff but it still worked out more expensive than mineral fiber and I also looked at that polystyrene sheet stuff but I read some horrible stuff about that polystyrene including how it reacts with the insulation of electrical wires.
I have got sheets of Kingspan for the little shed which joins on to the big one (which is an 8 x 6 apex) and is going to be my secret grow room but I had to get the thinner kingspan for that because the battons aren't very deep and it wasn't cheap.

 

I do wish I'd asked here earlier now as I've ordered the insulation and 100sq/M roll of DPM thinking it would be more or less right.

The DPM wont go to waste but I think I'm just going to have to use the loft insulation and suck it up now. I've calculated that I need to insulate an area aprox 50sq/M not including the floor so I ordered 5 rolls which cover aprox 10.5 SqM each. Cost £115 which was what drew me in lol

 

Hmmm...

 

Ok, new idea on the fly.....

Maybe I could section off 1/3 of the shed and turn that into an "office room" of sorts. I could concentrate on insulating and heating that area the most and store all my sensitive equipment in that while lightly insulating and boarding out the other 2/3 of the shed.
The small area would be easier and cheaper to insulate and keep warm etc while the other 2/3 could be kept as is. I could always fit a fan heater or oil radiator in the other 2/3 to use for when I'm actually working in that space. Now I'm thinking about it, it seems to make more sense than heating an entire shed just to protect stuff that could go in a smaller space.