Measure and cut your boxing timber to length then fix in position, keeping level. Cut your steel mesh to fit about 50mm less than the boxed area. Cut enough lengths of D10 steel rods and bend one end about 200mm creating a 90-degree bend. Fix with wire ties to the mesh about every second hole placement on the block.
Step 3
Mix five parts builder's mix with one part cement, add water and mix together to a porridge-like consistency in a concrete mixer or wheelbarrow. For best results follow instructions on cement bag. Pour in the concrete, lifting the mesh with a rake to sit in the centre. Using a straight edge seated on the boxing, screed off the concrete in a back and forth motion to level.
Step 4
Allow the concrete base to set for at least 24 hours. Then mix a bag of pre-mix mortar with water - again following the instructions on the bag - creating a fluffy consistency. Spread the mortar on to the base and between each block and start laying your concrete blocks, making sure each row of blocks is level by tapping it into place. Cut the blocks to fit where needed for each row.
Step 5
With the block framework now finished, leave it to dry for at least 24 hours before filling the block work with concrete slurry.
For the chimney, stack two blocks side by side in a crisscross manner, using a support on the inside until mortar has set.
I made the chimney high enough to draw the smoke from the fire away from the people sitting near the barbecue.
Step 6
For the roof, box up an even overhang about 100mm either side of the block framework, with supports underneath and boxed ends to hold in the concrete. For the front, mark and cut using a jigsaw, creating an even curve to the underside. Cut out an angled shape from the side overhang for the top of the roof shape and fix your 6mm ply to fit the curved shape.
Stop any sag when fitting the wire mesh and laying concrete.
Materials
Cement
Builders' mix
Steel mesh
D10 steel rods
Wire ties
150 series blocks (frame)
200 series blocks (chimney)
Mortar plaster
100x25mm boxing timber
18mm plywood
6mm plywood
40mm screws
Tools
Wheel barrow
Spade
Rake
Level
Tape measure
Pencil
Square
Bolt cutters
Pliers
Trowel
Block layers trowel
Screw gun
Straight edge/screed
Protective safety ware
Jigsaw
Grinder with masonry blade