Build a partition from aerated concrete

If you want to retrofit a room, you can choose between an aerated concrete wall or a drywall stud wall. Here is our guide to building an aerated concrete wall.

Anyone who chooses aerated concrete bricks when building a partition can count on several advantages. These walls are very robust and offer good sound insulation and fire protection. At the same time, the weight of the solid partition wall may need to be taken into account statically, especially if it is to be bricked up in the attic.

Compared to solid construction, drywall is cheaper, may be quicker to build and not as wide as solid partitions. However, the load-bearing capacity for suspended loads is not as high here as with the aerated concrete wall.

If you have decided on the partition wall made of aerated concrete, you can proceed with the construction according to the following instructions:

Prepare the surface for the partition

Draw a line where you want to wall the new wall. There you clean the screed with a wire brush. Cover the bottom left and right of it with paper and tape. Spread an elastic primer with the brush, then the mortar will adhere better to the screed.

A primer is applied to ensure that the mortar adheres better.

Photo: Quick Mix

You need a flat floor to wall the walls

To build a neat partition, you need to level rough floors. The best way to smooth them is to lay a thick bed of repair mortar no more than 1.5 centimeters thick. Although it is firmer than everyday cement-sand mixtures, it is still easy to work with. Mix the mortar with water according to the instructions for use. If you want to make your work easier, use a whisk. Now apply the mortar to the matt damp primer and smooth it out. If the floor is level, you can use the aerated concrete adhesive immediately after priming. With this you have to brick the wall. It is important that you only mix as much adhesive mortar as you can process in half an hour. Otherwise the mortar is no longer liable. For 11.5 centimeters thick stones, you can count on 2.5 kilograms of dry mortar per square meter of wall area.

It is best to level the floor with a 1.5 centimeter layer of repair mortar.

Photo: Quick Mix

Set aerated concrete blocks

Use a notched trowel - up to three millimeters - to thinly comb the mortar onto the face of the first aerated concrete block. Wet the stones in the thick bed with a puff and water. Now position the aerated concrete block correctly. Use a spirit level to check whether the stone is level. Use a rubber mallet and light strokes to align the stone horizontally. You align the escape with a chalk line.

Use the spirit level to check whether the stones are straight.

Photo: Quick Mix

Watch out! Butt joints must never be on top of each other. Therefore, start every second row with a half stone. To do this, place an angle iron on the stone and draw a line exactly in the middle. Now cut the stone in half with the AAC saw. Edit the passport pieces as well.

To ensure that the butt joints do not lie on top of one another, saw through the aerated concrete blocks in the middle and start every other row with a half stone.

Photo: Quick-MIx

Assemble the wall anchors

In every second row of stones you have to anchor anchor bolts into the wall. This prevents the partition wall from tearing parts off the old wall. On the top of the first row, apply a thin layer of adhesive mortar.

The installation of anchor iron prevents the new wall from tearing off parts of the old one.

Photo: Quick Mix

Embed rail

Bend the wall anchor until it dips into the mortar bed. When putting stone on stone, mortar often oozes from the horizontal bed joints. Under no circumstances should you continue to use this. The highly absorbent aerated concrete has already drained plenty of water from it.

Bend the wall anchors until they dip into the mortar bed.

Photo: Quick Mix

Lay the lintel

Install a lintel over passages and doors. This is lower than the wall stones. Unlock the stones on which the lintel rests. The fall should be flush with the neighboring stones. When installing a normal room door, you need a wall opening of approximately 188.5 centimeters. But it is better: 200 centimeters high and 88.5 centimeters wide.

Install a lintel over passages and doors.

Photo: Quick Mix

Close the ceiling joint

You should mortar the slot to the ceiling well. The best way to do this is with a small, handy trowel. You can continue working after two days of drying. If you want, slit grooves for the cables with a groove scraper. With a hole drill, you create space for switches and sockets. Special aerated concrete dowels are required for fastening. Sweep the wall with the broom and fill pre-wet cable slots and other recesses with plaster. You should fill flat dents with joint filler. The primed surface can be tiled, filled, plastered and finally painted or wallpapered.

It is best to close the ceiling joint with a handy trowel.

Photo: Quick-MIx