How to drill in hollow brick ? Which dowel to use ?

To ensure your success, you must systematically anticipate and prepare for your work. Without it, in the least worst case, you do not achieve your objectives, in the worst, you have deteriorated the premises. As far as the drilling of walls is concerned, you can quickly reach the worst. So here’s what you need to know to drill into hollow brick.

Identify classic hollow brick

The classic hollow brick is inexpensive and differs from the so-called “alveolar” brick by its thickness and the way the cells are placed. The standard hollow brick size is 20 cm and it is generally mounted with conventional mortar. Very durable, it is however much less efficient in terms of insulation than alveolar brick, which for this reason tends to replace it more and more on construction sites.

Hollow brick is usually covered with plaster, except perhaps in garages, laundry rooms and attics where it can be simply painted. This is why it is necessary to take surveys in the wall you wish to drill to understand how it is made and to determine the best method for making the holes.

What can be fixed in a hollow brick wall?

Before considering fixing heavy things in a hollow brick wall, it must be checked that the wall is sound and without deterioration. Apart from any disaster, the hollow brick, a durable material, retains identical mechanical performance over time, regardless of the date of construction of the building.

Be aware that the main criterion of a construction material is the crush resistance. All other characteristics are usually neglected. The hollow brick is a friable material and therefore fragile to drilling: it is likely to break if it is not correctly drilled.

on pull-out resistance is also limited. It is therefore advisable to be modest about your ambitions and limit the weight of the object you want to hang on the wall. If, for one reason or another, you have no choice, it is safer to place feet or other angle-type supports to prevent the high ankles from being pulled out. With a little ingenuity, what appears to be a disadvantage at the start can often be turned into an advantage or cleverly camouflaged.

Drill hollow brick: dowel and drilling method

It’s here charge supported by the fixing system which determines the diameter and the nature of the ankle. To determine the load of a piece of furniture, for example, add the weight of the piece of furniture itself and those of the elements that you plan to place on it.
The diameter of the hole is of the same dimensions as that of the dowel.

Choose a hollow material anchor. The ankle crampon only suitable for small wall decorations. For heavier loads, you will have to turn to expansion anchor metal dowels. The chemical anchor can increase the mechanical characteristics of the hollow brick, but it is a very expensive solution.

It is absolutely necessary to drill to the hollow part of the brick. Make a pilot hole 5-6 mm deep before making the final hole. To pierce the brick without bursting it, you can use a stamp. The drill fitted with a concrete-type drill bit will also do the trick.

If you use a drill, as with any drilling, the speed is a function of the diameter. It is then necessary to be delicate: it is essential to press while retaining the drill because it is necessary to anticipate the moment when you will reach the hollow of the brick (after approximately 1 cm).

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