New obsy build - advice on insulation?

[DJT (David)]

Hi
I am in the middle of an obsy build at the moment and I am about to get the roof on and add the cladding. I intend to use some moisture membrane inbetween the cladding and the struts as well as under the roof but wondering if I need to be thinking about insulation? Is it necessary in terms of impacts on an obsy setup? Not really used to seasons in sydney but temperatures dont tend to drop below 8 or so degrees in winter, positively mild where I am, however I would imagine the heat build up during the day might have an impact though of course there would be a cool down when the roof rolls off?

If anyone has any advise it would be much appreciated

This is a full timberframe build with a roll on roll off roof (well, half a rolloff anyway) and I get the impression the plans were drawn up by someone with a vested interest in the timber trade

http://i1154.photobucket.com/albums/...ndoftheday.jpg

[Marke (Mark)]

David have a look at how I did mine in this forum , best thing to use in wall and roof is Air-cell Insulshed : http://shedblog.com.au/buy-insulshed...on-by-air-cell

Mark

[DJT (David)]

Originally Posted by Marke

David have a look at how I did mine in this forum , best thing to use in wall and roof is Air-cell Insulshed : http://shedblog.com.au/buy-insulshed...on-by-air-cell

Mark

Cheers Mark

[sheeny (Al)]

G'Day David.

The moisture barrier is essential if you want to stop the roof from condensing and dripping all over your scope.

Insulation, well... I'm not so sure. Insulation just means it heats up and cools down slower. Not sure if that's really what you want.

With insulation, it won't get so hot in the middle of the day, and it won't get so cold in the middle of the night while its closed, but it will take longer to cool early in the evening.

Rather than insulate, I would probably try to double skin the roof (and maybe the western wall?) so air can circulate between the two layers. Without insulation the obs will follow the ambient temp as quickly as it can, but the double skinned roof will stop a lot of heat entering from the sun.

Al.

[DJT (David)]

Thanks Al

This could get interesting..

I see where you are coming from on the long evening cool down if I insulate. Not decided on roof materials yet so not sure how much condensation will be generated.I am putting exterior ply up on the rafters and maybe shingles. Or maybe colour bond..hmm

[sheeny (Al)]

Double skinning will work well with colorbond, and the moisture barrier will be essential. Metal cladding will supercool and condense dew on clear nights.

Exterior ply and shingles I imagine would be less likely to trigger condensation than metal, but that's not to say it won't happen. I've had condensation form on the inside of my POD on the odd occasion so I'd expect it to happen infrequently with ply and shingles too.

I'd really like to hear from anyone who had and uninsulated obs and then insulated it to see what the difference is. Insulation is not a no brainer IMO. It might be good, it might not, it might even depend on how its done.

Al.

[Marke (Mark)]

I can tel you with my colour bond roof and the insulshed I get no condensation what so ever. The wall will get dew on them during the night with roof off but never when its closed .

[DJT (David)]

Hi Mark
Any issues cooling down when you open up in the evening? Or is it not material? Your pretty local to me so would face the same issues I might?

[Marke (Mark)]

No prob cooling , dont know why people worry so much , with the roof back
inside temp equalizes faster than the OTA will . I just roll it back before dark and all is good by the time I want to start using it. We have pretty temperate weather really . I have inside lined with ply as well and temps stay pretty even as long as it is locked up.

[DJT (David)]

Ok

Thanks Mark and Al

I will do one or the other anyway. Leaning towards Marks as I have seen similar products which also act as a moisture barrier.

Any other input much appreciated.

[Marke (Mark)]

Isulshed is a moisture barrier as well as giving a bit of insulation it was designed for use with colour bond sheds and roofs.

[sheeny (Al)]

Originally Posted by DJT

Ok

Thanks Mark and Al

I will do one or the other anyway. Leaning towards Marks as I have seen similar products which also act as a moisture barrier.

Any other input much appreciated.

Sounds like Mark's got a handle on it!

Al.

[baileys2611 (Simon Bailey)]

I'm interested in how you insulated the floor? I Just ordered a roll of Insulshed for my shed roof and am thinking of using it for the walls also - but am wondering if I could put some on the floor to help make a barrier against moisture seeping up from the slab.

Would that be a "bad thing" I wonder.

[niko]

they are quite some wall studs you got there! They look bigger than 90mm - you should be right in any conditions!

good luck with the build

[DJT (David)]

Originally Posted by niko

they are quite some wall studs you got there! They look bigger than 90mm - you should be right in any conditions!

good luck with the build

hmm..140mm for the studs..This is THE over engineered shob (SHed & OBservatory)

Thanks

[DJT (David)]

Originally Posted by baileys2611

I'm interested in how you insulated the floor? I Just ordered a roll of Insulshed for my shed roof and am thinking of using it for the walls also - but am wondering if I could put some on the floor to help make a barrier against moisture seeping up from the slab.

Would that be a "bad thing" I wonder.

I dont have a concrete slab. This is sitting on concrete piers. However there is weedmatting and gravel under the floor and there is 18mm exterior grade ply for the floor on the effing huge bearers and joists.. If you are using a concrete slab you really should have a waterproof membrane from what I have read.