Bricklayer

Interview with Knut, a bricklayaer

Photo: ScandinavianStockPhoto, Dmitry Kalinovsky.

About laying Light Expanded Clay Aggregate (LECA) blocks, rendering walls, tools and HS&E

 

What types of materials do you build with?

We have two main types of building materials: Light Expanded Clay Aggregate blocks and bricks. Most walling is done with lightweight clay blocks of various kinds, and most people use LECA blocks. Lightweight clay blocks are made of clay that is fired. The clay that is used has a low lime content, and the firing process is different from the usual process.

 

Why are lightweight clay blocks used so much?

Lightweight clay blocks are sound-insulating, heat-insulating and fireproof. They are well suited to building interior and exterior supporting walls, façade walls and retaining walls. They are also relatively easy to build with. Just now I’m building a basement wall with leightweight clay blocks.

 

What do you need to be aware of when building walls?

The wall must be straight both vertically and horizontally, so I use a spirit level and lead lines. I set up a cord from corner to corner as a guideline for laying the bricks. When I measure out the wall, I must calculate 10 mm for every joint. I must also make sure that the vertical seams in the brickwork are not placed directly above each other, in order to give the wall greater bearing strength. I insert reinforcements in every other mortar strip to make the wall stronger.

 

How do you treat the wall when you have put up the blocks?

The wall must be plastered to give it a smooth surface and to prepare it for any further treatment such as painting or wallpapering. This basement wall, for instance, will be painted. The external wall must be plastered to protect the brickwork from the elements. When we plaster a wall, we apply finishing plaster. There are many types of mortar and many techniques for plastering walls, depending on what kind of wall it is: Is it an external or an internal wall? Will the wall be supporting heavy or light loads? How do we want the surface to look?

 

What kinds of tools do you use?

A spirit level, lead lines and bricklayer string are used in the preparations to build a straight wall. I use a brick hammer to trim the bricks and a brush to keep the wall wet. I use a smoothing trowel to apply mortar to the wall, and a trowel to apply the plaster. There are many different tools for plastering a wall. What I use depends on how the wall should look. If I am going to make fine joints I use a tool called a caulking trowel. I am very careful to clean my tools after using them. It’s irritating to find dried cement on a trowel when I’m going to use it.

 

What kinds of HS&E (health, safety and environment) measures do you take as a bricklayer?

There is lime in cement, which can corrode your skin and irritate your mucous membranes. It is especially dangerous if lime comes into contact with your eyes. If this happens you must rinse your eyes with clean water immediately, and see a doctor quickly. If there is a lot of dust at the workplace I use a dust mask. Many people think that I overemphasise safety concerns, but I have noticed that dust irritates my throat, and I don’t want to get ill.