Dowels in hollow bricks? - Tips for Safe Retention
Unfortunately, dowels in hollow bricks are not that easy. However, with the following advice, screws also hold firm hold in this masonry.
The use of all-purpose dowels
The all-purpose dowel is suitable for almost all walls. Depending on the nature of the wall, it reaches the stop by spreading or knotting. Since the hollow brick dowels encounter both solid areas and cavities, such a dowel is almost always ideal for fixing screws in the masonry.
Use the turning in drilling
Who drills a hole in a hollow brick for a screw, should always use the turn. This avoids that the impact mechanism can break away internal webs. The craftsman must be prepared for the drill to re-contact after a short break in the cavity. Red drilling sand proves that it is really a brick wall.
The Appropriate Cavity Dowel
A Cavity Dowel is designed to knot in the cavities of the wall. He is too wide to be pulled through the hole. However, this anchor does not hold in cellular concrete, which is why this dowel shape is rarely used in shelves as mounting material. Dowels for hollow bricks are also shaped slightly differently than cavity dowels for plasterboard walls.
Choose the right dowel length
When choosing the dowel, its length must fit the wall. Plaster or other layers that can not hold the screwed-on shelf must be included in the dowel length. Only then is this behind the non-bearing layer still long enough to transmit his power. The drill hole must be much deeper to allow the screw to pass through the dowel and deform it accordingly.
The Use of Liquid Dowels
A so-called Injection Dowel consists of a quick-setting resin that is injected into the drilled hole. Simply insert the correct dowel into the still liquid dowel and let it harden. So that the resin does not run in the hollow chambers, first insert an anchor sleeve into the hole. Screw in the screw after hardening.
Better drill a little smaller
To prevent a porous brick from crumbling when using the dowel, select the drill bit a bit smaller. Once the necessary depth is reached - if the dowel does not fit - carefully and manually rework. Too deep, the hole should not be, after all, hollow bricks are also intended as insulation. An adhesive tape on the drill helps to maintain the drilling depth.