DIY Outdoor Fireplace install - chimney/flue

[ProjectPete]

I'm installing an outdoor fireplace in my alfresco area and need to run the chimney flue through the roofspace above. There's about 1.6m of roof space.

I understand it should have a triple sleeve set up however I'm wondering if anyone has any experience installing one themselves and if you think it's really necessary. Given there's no insulation in that area of the roof space (ie. nothing flammable) I don't see the need for triple sleeve.

Main concern is, the price to do it triple sleeve is about $800 while single sleeve is about $150-200. If I was concerned about safety/flammable I wouldn't question the price, but I think it's overkill in this situation.

TIA

[Jason]

No worries, thanks for the update Pete. 

Do you think you'll use the fireplace all year round or just in winter?

Jason

[ProjectPete]

I'm a fire lover @Jason so literally use it year round, except 40 deg days but use it as often as possible. I've got 2 portable fire places so they move from alfresco-ish area to pool area and back. But looking to have some fixed fireplaces too.