Building a fireplace

[Rick]

I am trying to build a fireplace, to put a wood burner in.

I intend to use clay flue liners. I intend to build a double skined chimney, initally from 7N blocks, but then into something that looks good once it comes out the roof.

So far I am up to lintel level, I have my lintels cut to size.

I have worked out how to hold my bottom flue liner in place, while I go up a level, but I have some puzzles ........

What holds the bottom flue liner in place? is it simply the fact that it has motar on the sides. If this is the case, then I assume I have to pack this in quite well.

Whats finishes the top of the opening ? I am thinking of putting a cement sheet in (like MDF but made of cement), all cut to shape, with a hole for the flue liner to protrud through.

Once I have the first flue liner in, am I supposed to fill between the flue and the brickwork with vermiculite or a "week lime mortar" ? If the liners are not held on the way up, then they all rest on the bottom one.

Do I seal between the flue liners with fire cement ?

Thanks Rick

[Gerry]

I'm sure others can give you better advice but when I had to rebuild and reflue a very old chimney (which had been badly built). I held the bottom flue in place by creating small lips (1/2 ") around the edge and a few nails driven almost into the wall. I did not use fire cement between the flues. The mixture which surrounds the flues all the way up is a very weak and fairly dry cement/sand mixture (1 cement to ten sand). This allows for expansion - otherwise the flues crack. I made a fairly straight chimney but there is an opinion here that you should hide daylight twice - an 'S' bend shape.

Good luck

Slán