How to cast and create a concrete mosaic Slab
Here are the 10 steps to creating a concrete mosaic slab. Make sure you have ready :
soft sand – sharp sand – cement- wooden frame mould – pebbles- stone – water – scoop/trowel – mixing tray – wooden guides – wooden float – metal reinforce grid.
- Use your wooden float and guide bars to create a level layer around 5mm thick of soft sand ( also known as building or brick laying sand and is often in colour) in the base of the mould.
2. Place out the shapes to make a picture upside down pressing them gently into the sand layer to stop them moving once you are happy with their position.
3. Start filling in the gaps with pebbles and p9t toppers. KEEP IT SIMPLE!!! Use bold patterns and contrasting colours to make it stand out, don’t make complicated shapes.
4. Use the best flattest side of the grave embedding it slightly into the sand bed. Make sure there is a gap between the gravel and stone for the concrete to pour into and bind the surface together.
5. Once the design is laid out check it and adjust where necessary then make sure its secure and won’t move about when you pour the concrete.
6. Mix the sharp sand with the cement, the ratio will be measured out as a four parts sand to part cement.Make sure it is thoroughly mixed get to the edges of the tray right into the corners mix the sand and cement till it is all one consistent colour. Leave a few scoops of dry mix to one side. Add water slowly, gradually to the rest of the mix so that it becomes all wet (no dry spots) and keep mixing and adding water until it becomes like the consistency or porridge od rice pudding. If it is to wet or runny use the free mix saved on one side to thicke it make sure it is consistency moust through the whole mix.
7. Scoop the mix over the mosaic being careful not to disturb any of the peices, filling into the corners and edges, fill the mould half way up.
8.Use the wooden float to tamp down the mix so that it levels out and fills in the bottom of the mould.
9. Sit the mesh on the surface of the concrete pushing it very slightly into the concrete.
10. Fill the mould right to the top of the mould, using the wooden float to tamp the surface getting it even stop when the surface gets covered in the a sheen of water. Store the mould on a level surface in a dry place where it won’t get knocked or disturbed. Clean everything that I contaminated with wet cement with cold running water.
To view the next stage through video click here