Dowelling exposed aggregate concrete slabs - The most important information

Exposed concrete panels can be drilled without any problems. This makes it possible to use dowels that extend the uses of the panels. It is even possible to attach dowels to the exposed aggregate concrete slabs. The process hardly differs from conventional drilling work.

Material and tool list

  • Dowels in the desired size (all-purpose dowels, expanding dowels, multi-zone expanding dowels)
  • Rotary hammer (€ 159.90 at Amazon *) or percussion drill
  • Suitable size drill bit (diameter of the anchor)
  • Folding rule
  • Hearing protection
  • safety goggles


Before you can put dowels on the exposed aggregate concrete slabs, you have to turn them over. In most cases, walkway or patio tiles can be lifted with a little force, while you have to peel off tiles that are attached to walls. Be careful not to damage the plates. Next, mark on the underside where the drill holes for the dowels must be. There are a few points to consider:

1. Note the edge and center distance. This is the only way to guarantee that the panels are not damaged by the drill hole and that the dowels are correctly positioned.

2. The markings should not be placed behind a pebble. Otherwise the stones could break out. For this reason, you should choose the spacing between the granules for the drill holes.

Dowelling exposed aggregate concrete slabs: Instructions

1. Fix exposed aggregate concrete plate

As a precaution, clamp the plates in place. This prevents it from moving while drilling. Then pull the protective clothing, as much dust will be made.

2. Align

Start to start the drill (48,00 € at Amazon *) on the mark. You just have to lead the drill as possible in the washing concrete as possible. If this is not the case, the bore will be awry and the dowels can not be used. Drill hammers can be easily aligned like impact drilling machines as they need to spend less power. Do not forget to drill from the bottom.

3. to drill a hole

Now drill the hole for the dowel. Proceed as slow as possible so that the material is not unnecessarily under pressure. Hold the machine straight and drill deeper and deeper into the washbue, until the necessary depth is reached.

4. Determine drilling depth

The depth of the drill holes is either given by the dowel manufacturer or is determined by them. In this case 10 mm are added to the dowel length. Check the determined drilling depth at regular intervals.