Primitive Technology: A-frame Roof Tile Factory
Off to make an A-frame hut This will form the central ridge of the hut It is cut to a 4 m length The hut site Hammering in post holes 4 m apart and 0.5 m deep Two 2.5 m posts are inserted into the ground 0.5 m deep Loya cane is cut to tie on the ridge beam Square lashing is used to secure the ridge in place 2 m above the ground 18 x 3m rafters are laid against the ridge, 0.5 m apart 4m wide x 4m long x 2m tall A-frame structure Cutting palm thatch for the A-frame Each frond needs to be split in half lengthways Vines are used for lashing The fronds are tied to the rafters with vine They are laid at the ground level first Subsequent layers are laid over previous ones so they shed rain When one side is finished, it can be used as a shelter while the other side is being built The ridge line is still uncovered Bundles of whole fronds are lashed together These are then lifted onto the roof with a pole Pairs of logs, 0.75m long are lashed together and placed over the ridge to keep the capping on. These are called "jockeys" because they straddle the roof like a horse.
Any leaves sticking out of the interior are pushed back in for neatness Debris is swept out and the floor is graded flat with a stick The hut took 10 days to build and 2000 palm fronds The cane tile mold and wooden form are retrieved from the brick and tiled hut An area is cleared for a clay slaking pit A pit is dug about 1 m in diameter Mud is made A table for forming tiles on is made from mud A white tailed rat goes for a swim Clay is located up a dry side creek The clay for tiles needs to be dense and plastic for strength, a higher quality than that used for bricks It's dug with a digging stick and put into a pot 25 pots of clay were carried to the pit The clay is then slaked with pots of water It is trodden on to get rid of lumps A large stone is obtained for an anvil to crush grog on Don't tread on me The snake, a non-venomous constrictor, is about 3 m long Old roof tiles from a previous hut are collected to be used as grog in the clay The tiles are crushed on the anvil with a hammer stone to form a powder that will be mixed with clay The grog is mixed with the clay so that when it dries it won't crack much The clay is made into 12.5 cm cubes (measured 5 finger joints long) The cubes will each make about one tile The simple A-frame hut provides a large dry work space in wet weather To make a tile, the flat slab is dusted with dry soil so the clay won't stick Clay is then pushed onto the surface and flattened out The tile frame, made from a strip of cane, is then used to form the clay into the trapezoidal shape of the tile The tile is then moved onto the tile form The mold is removed and the tile curves over the wooden form The tile and form are then taken to the drying area The sides of the tile are slightly pressed onto the floor and the tile form removed so that the curved tile is left standing The floor space near the low sides of the hut is used to store the tiles, keeping them out of the weather One 4m row equals 22 tiles 44 roof tiles Tiles safe from the rain 88 roof tiles It's worth mentioning that the table, mold and frame should all be dusted before use to stop clay sticking Wetting the clay stops it sticking to your hands while forming 132 roof tiles During the night, a white tailed rat graffitied the tiles with it's paw prints A local lizard was left speechless following the incident Mud is used to form a stable slab foundation for the kiln Back at the brick hut Fired bricks are taken to build the kiln 74 bricks are needed 4 rows of 3 bricks are laid down to form lower firebox layer Then another 4 rows of 3 bricks are laid on top of the first to form the upper firebox layer Then 5 layers of 10 bricks are added to form the ware chamber (where the tiles go) A 75 cm x 75 cm x 100 cm wood stack is marked out Standing dead wood is collected and broken into 75 cm lengths for the kiln The wood is stacked between the upright stakes for storeage Fire by friction Fire drying the tiles Unfired bricks will be used to form the grate of the kiln so they get fired at the same time as the tiles 12 bricks form the grate Fire is transferred to the kiln to start the drying process Clay needs to be completely dry before firing. The best way to do this is in a kiln with a small fire in the ash pit The tiles are stacked into the kiln in 3 rows, 2 with narrow side down and 1 with narrow side up so they fit neatly I was able to fit 42 tiles in the kiln While the tiles dry, the kiln is plastered with mud to stop cold air getting through the brick joints The fire was maintained in the ash pit to further dry the tiles Broken roof tiles were placed on top of the new roof tiles to keep the heat in during the firing Wood was then placed in the upper fire box layer so the proper firing could commence The fire in the lower firebox layer was stoked to burn the wood above After about an hour wood gas burns above the kiln Periodically, coals are raked out of the lower firebox level to maintain airflow through the kiln Wood must be fed through the three upper firing ports during the whole firing Nearly 2 hours in, the tiles can be seen to be glowing red to orange hot They must all glow at least dull red to not dissolve in water The whole firing took 2 hours and 13 minutes, stopping only when the tiles were glowing red hot The next day the tiles were taken out Superficial cracking, clay just slightly glazed in some places All tiles must be water tested, better to dissolve now if underfired than later in a roof The sound of well fired tiles The now fired bricks that were in the grate level 2 bricks broke during the firing (probably poorly made) These are re-used as grog for clay The newly fired bricks are water tested All the bricks passed the water test They are stacked next to the hut for storage All 42 tiles passed the water test They are stacked against the bricks which act as a back stop 42 good tiles The next batch of bricks and tiles are stacked into the kiln A ridge of bricks is put on top of the tiles and fired roof tiles are placed on top to form a roof The fired tiles' first job is protecting the next batch from rain A-frame roof tile factory
2024-10-04 14:29
