Some calculator question?

[david s]

1/4 inch all around is 1/2 inch of expansion space - 1/4 on each side

Yes that's correct and if one is going to the trouble of including an expansion joint, that's why I said "no point in not having enough space" It needs more than is required to ensure it can do its job.

[deejayoh]

At around 500 C the expansion of brick is around 0.5%. So say a dome of 1.0 m (1000 mm) then 0.5% is 5 mm (just under 1/4") So 1/4" all around is about right. There would be no point in not having enough space.

1/4 inch all around is 1/2 inch of expansion space - 1/4 on each side

[david s]

At around 500 C the expansion of brick is around 0.5%. So say a dome of 1.0 m (1000 mm) then 0.5% is 5 mm (just under 1/4") So 1/4" all around is about right. There would be no point in not having enough space.

[Canada 150]

Got it. I think that's how thick the cardboard I have is. I'll see if I can find something thinner!

[deejayoh]

If you are leavin a gap, then yes, you need to add that to the length. IT = radius of your dome. But FWIW, 1/4" seems like an awfully big gap. That's 1/2 an inch of expansion room.

[Canada 150]

quick question - In the dome spreadsheet calculator it provides a recommended IT length. Do you adjust this length for the cardboard expansion joint around floor (ie add a 1/4") or just edge the dome back in?