Thread: Shed insulation

Ten years ago we built a 200m2 shed, 5m roof height. I used fibreglass anti con mat in the roof as it was built. The walls I used poly batts, to attach I just used construction adhesive. On the inside I double lined with a second layer of corrugated iron. Looks really nice, and works well. We lived in that shed for 4 years, a single 3 kw reverse cycle ac was enough to take the heat edge off the 80m2 living section, and a wood burner kept it toasty warm throughout winter.

I've had good results with styrofoam sheet bonded with liquid nails onto the internal side of the colourbond. Agree with the floppy stuff being a haven for starlings and rats.

I've just priced up materials for a ~150m^2 shed with R2.8 walls (90mm fibreglass batts) and R5 roof (200mm fibreglass batts).
It came to ~$NZ6k for walls and roof, with another $2k for 75mm of polystyrene in the floor.

But that's not the end of it, to get the best results you need to line the walls/roof to trap air. Each air gap is worth an R value of about 0.2. Batts which external or internal air can blow through are close to useless. I've got ~$NZ2700 down for gib to line the walls/roof, I haven't priced other options for lining, but considering corrugated iron on the inside of the pitched roof, need something tougher on the walls.

The aircell type insulation is IMO equivalent to building paper. It's enough for your moisture/condensation management but offers no insulation where it's pinched over rafters/purlines and isn't enough if you need to combat either heat or cold. I looked up the stuff used in a mates shed and it's only just R 1.0.

My big question is insulated shed doors. Roller doors are out with no insulation possible, tilt and sectional doors can take up a lot of room inside. Sliding doors are generally a maintenance PITA.

Just coming back to this again after a while. The shed is being delivered in 2 weeks time . Mind you, there's no slab yet so the build might be a little way off yet.

Originally Posted by Bundalene

I know the thermotec material is excellent, having used it for heat proofing our Defenders.


There is a mechanical workshop across the road from us who have a low density bubble type of material as their insulation and they can't stop sparrows from destroying it and making their nests.



Erich

Thanks Erich, the last thing I want is my shed to become home to birds & have bits & pieces falling down.

Originally Posted by Pedro_The_Swift

Maybe sometimes Scott,
More is better.

Maybe, but I just want to make sure after dealing with sales staff who often tell tales.

Originally Posted by Don 130

Check the R value of anything you consider. When I built a shed the builder would only fit the bubble type. After much enquiring I found out it was only R1.2. Not worth the money. I didn't fit any and haven't regretted it.

Originally Posted by Kev the Fridgy

Fibreglass may be "Old Technology" but have a very close look at "R" values, personally and IMO anything under R2.5 or preferably R3 is not worth the costs difference, from what I have seen F/Glass still out performs everything else when it comes to cost V R value per square meter, when it's all said and done you want the best performance you can afford.

The Thermotec insulation is:
E- therm 5mm = RO. 16
E- therm 6.5mm = RO. 20
E- therm 8mm = RO. 25
Information from here:
E-Therm Insulation | M.E.T. Sundry Supplies Pty Ltd


After enquiring direct to Thermotec, I've found they don't supply the general public. A call to their only distributor in Sydney (and talking to 2 staff members who didn't know they sold it), I found that the shed supplier was wanting to slap on a $1000 mark up.
I can get 240sqm of 5mm for $1888, 6.5mm for $1918 or 8mm for $2058.

For the sake of $170, I think I'll go for the 8mm stuff.

Originally Posted by Scouse

The Thermotec insulation is:
E- therm 5mm = RO. 16
E- therm 6.5mm = RO. 20
E- therm 8mm = RO. 25
Information from here:
E-Therm Insulation | M.E.T. Sundry Supplies Pty Ltd


After enquiring direct to Thermotec, I've found they don't supply the general public. A call to their only distributor in Sydney (and talking to 2 staff members who didn't know they sold it), I found that the shed supplier was wanting to slap on a $1000 mark up.
I can get 240sqm of 5mm for $1888, 6.5mm for $1918 or 8mm for $2058.

For the sake of $170, I think I'll go for the 8mm stuff.

Numbers like that mean it's almost a waste of time. A sheet of building paper to create an airgap will give an R value of 0.2

A R value of 0.2 means with a temp of 60C on one side (roof in the sun) and 20C inside you'll be gaining heat at the rate of 200 watts per square metre.
Every 10 square meters is like having a fan heater inside.

If you can get R3 insulation into the roof you'll drop that to 13 watts per square metre.

An interesting topic as I've often wondered how effective the stuff I put in 4 years ago really is so I've just done a little experiment.
The outside temp in direct sun, which my shed is, was 34.1 as shown on the Sontax thingo.
The inside shed temp was 27.2 as shown on the other thingo.
I had one car bay door open.
Shed is 6.5x12.5 C/bond on conc slab.
I used stuff called AIR-CELL INSULSHED.
Stamped as Oz made too.
Hope this helps.
Steve

Is there a particular reason you are thinking of putting the slab down first?

When I built mine, I asked about which order to do it in, and the guy said that it didn't really matter, but with putting the slab in after the shed is built, it goes off a little slower, meaning less cracks, and it seals around the edges, helping to keep water out.

Just a thought...

I built in Queensland 2 homes with Colorbond cladding and in both cases I used Air-Cell in the roof and walls. The result was fantastic, we never used AC in both houses