bricklaying (Building materials)
Sharp sand is a course and gritty material, normally used with other aggregates for making concrete and floor screeds bricklayers always use soft sand known as builders sand it has a finer grade than sharp sand and is mixed with cement to produce mortar.
The most commonly used binder in bricklaying mortars is ordinary Portland cement o.p.c. masonary cement is fine but is rarely used as it contains only 75% o.p.c. the rest being a filler which has no binding capability.
In the 19th and early 20th century hydrated limes were used as the only binding agent in mortars even if they were still available they would not be practical for the majority of building work as they harden slowly rather than set rapidly as cement mortars do today powdered limes are often added to Portland cement to improve workability being water retentive lime also improves the bond with the bricks and helps against rain resistance.
Cement sand and water alone often produce harsh mortars which are difficult to use their workability can be improved by adding lime or liquid plasticisers which entrap minute bubbles of air in the mortar you should only use permitted plasticisers such as fed mix the builders alternative such as fairy liquid should be avoided as it produces uncontrollable amounts of bubbles producing weaker less durable mortars.
There are 2 ways of producing coloured mortars the first is to buy pre coloured sand the other is to add a pigment such as cement tone make sure you gauge this properly as it will come out different shades of colours.
Ready mixed mortars
Ready mixed mortars are available to buy, they are delivered in plastic tubs and have retarders in them to make them last 24 hours, the trouble is they are more expensive and in bad weather they will be wasted.
Sometimes after building a new wall white patches can appear on brickwork this is because of the soluble salts in the bricks being brought to the surface by water usually after the first heavy rainfall once the wall has dried out efflorescence should not appear and should naturally weather away if not a brick cleaning acid can be used
Bricklaying Tutorial Links:
- bricklaying tutorial (How to set out and gauge your brickwork)
- bricklaying tutorial (Rules for cavity insulation)
- bricklaying tutorial (Foundations for a garden wall)
- bricklaying tutorial (cutting bricks)
- bricklaying tutorial (rolling the mortar)
- bricklaying tutorial (buttering up the perp)
- bricklaying tutorial (pointing)
- bricklaying tutorial (exercise)
- bricklaying tutorial (garden wall English bond)
- bricklaying tutorial (porches and extensions)
- bricklaying tutorial (porches and extensions part 2)
- bricklaying tutorial (porches and extensions part 3)
- bricklaying tutorial (porches and extensions part 4)
- bricklaying tutorial (porches and extensions part 5)
- bricklaying tutorial (Building materials)
- bricklaying tutorial (How to set out for a house)