Where to install Sizelation?

[rogerg]

Hi all,

I want to prevent dew forming on internal roof surfaces, to prevent possible moisture dripping on to equipment during the day (should have done this years ago). Moisture forms on the inside of the Colourbond and then can run to the roof struts where it pools and forms droplets.

Would I install Sizelation between Colourbond roofing and the steel frame structure (by removing the roof sheeting temporarily to do so), or would I install it to the bottom of the roof structure (by adding strips of metal to hold it to he existing metal struts)?

:question:

See attached to help explain what I mean.

Thanks,
Roger.

[acropolite]

Directly under the corrugated sheeting is the norm, often wire mesh is used to give extra support to the Sisalation.

[rogerg]

Excellent, that was quick and easy answered! Thanks :thumbsup:

It should be quite easy to remove the sheeting and insert the Sisalation.

[gregbradley]

Yes its also good to use safety mesh. You can buy it from a roofing supply store. Wrap a "runner" around the start of the roof and run it sideways and tie it off, wrap it around a beam and then itself 4 times.

It helps support the sarking. Run sarking sideways, it cuts with a Stanley knife, and start from the bottoms of the roof sheets. Overlap by a decent amount say 150mm.

An alternative, which is what I used, is simply to put foam cored insulation aircell type insulation. Bunnings sells it.Its about $110 a roll and a roll is 12m2 from memory. The Bunnings version is from Kingspan. A nice product.

No need for wire then as its more rigid and about 10mm thick. That will also keep your observatory less hot in summer. Its got an aluminium finish on both sides so I sprayed mine flat black to avoid light reflections.

Easy to handle and cuts with a knife, a very good product.

The problem with sarking is it will deteriorate eventually. Its not really a long lasting product but I suppose it will last 20 years so long as its not getting regularly wet.

Greg.

[rogerg]

Interesting. There's always an alternative to complicate the issue isn't there :) The aircell, looking on the Kingspan website, looks very similar to Sisalation. It's rolled like Sisalation, how is it more rigid or longer lasting? I'm hoping to go in to bunnings this afternoon on the way home from work to see them and compare.

[rogerg]

Well, I can't find anywhere nearby that stocks the Kingspan AIR-CELL which is suitable to the situation ("Insulshed"). Bunnings has the "Insulbreak" variant which would do, but is $342 for twice the quantity I need and wouldn't provide the stiffer advantage of the Insulshed.

My local hardware has the CSR Bradford Anticon, R1.3 55mm, basically Siselation with 55mm fibre bat on one side. The quantity is perfect, 18m2 when I need 16m2, and $115. Price is very appealing. So, I think I'll be buying that on the way home today (along with appropriate tape and wire).

Roger.

[GrampianStars]

I use this under wooden beams
http://www.bunnings.com.au/ametalin-thermalbrane-4-4-0-x-1500mm-x-20m-insulation_p0811014
:thumbsup:

[rogerg]

Thanks Rob :)

I did purchase the Anticon so will be going with that. Unfortunately life has got in the way, and installation got postponed. Currently slated for 3rd October, weather permitting.

The Anticon was recommended by a local builder I trust. In many ways I would prefer a product such as you have used, it looks very neat. But I'll see how the Anitcon goes - of course it'll be fine, it's just how much it bulges down and if that makes it look "unsightly" :)

[rogerg]

All done and installed :)

... although I hope to get some tape to seal the joins and a couple of holes scraped in the silver.

Hopefully will prevent the condensation, shame it will retain the heat in Summer though.

I think it's about the 3rd time that roof has come off and gone back on, eventually the screw holes are going to wear out :lol:

Thanks everyone.

[astro_nutt]

Very neat job Roger. If you want, you could insulate the walls with polystyrene sheet stuck on with water based liquid nails and cover that with black cloth.
Cheers!

[rogerg]

No intention to at this stage. if it weren't for the condensation dripping from the roof risking equipment damage I wouldn't have insulated the roof, as having just the tin conducts heat out so quickly once the sun leaves it, it really helps cool down times.

I'm hoping that with the roof insulated but the walls not, that the walls (which get very little direct sunlight from late morning onwards) will continue to conduct heat out. We'll see :)