I explain why I fill vertical joints and grooves in aerated concrete with glue-foam

Aerated concrete blocks from the manufacturer Sibithave grooves and recesses for grip - this is convenient. Blocks with a width of 400 mm weigh about 40 kg (and wet after rain are even heavier). Without grabs, it would be very difficult to lift blocks. But the side grooves in the blocks are also an excellent solution.

I know that some manufacturers in the European part of Russia do not make grooves and notches (they have simple rectangular blocks).

The grooves allow the vertical connection of the blocks to be foamed with adhesive foam. This solution makes the wall more airtight, because there are times when the block is corrected and a gap is formed in the vertical seam. Or the block geometry is not perfect. Therefore, most builders cover seams with mineral glue.

Some self-builders make grooves in blocks on their own, fill them with glue-foam. Foaming the seams between blocks along the grooves has an advantage over applying adhesive foam on vertical seams. Why? Watch the video with the authoritative opinion of the aerated concrete construction expert:

So my process is:

For the first row of masonry, I bought glue-foam from Sibit. Nice turquoise color of the foam, large foam output from the cylinder, adequate price.

Application and consumption recommendations are indicated on the bottle. Later I received a batch of glue-foam from a well-known Russian manufacturer:

The color of the glue-foam is gray, similar to the color of aerated concrete. After using several cylinders from this manufacturer, I can say that it expands stronger, filling all possible space in the grooves and it happens that such a picture:

I cut off the frozen foam with a clerical knife and put it in the gripper grooves in the blocks (then less mineral glue falls into them when it is applied). I foam it after the end of the row, after the mineral glue has set.

Glue-foam yellowed in the sun. Some believe that it will collapse in the masonry. Polyurethane is a durable polymer and in the absence of ultraviolet light, the lifespan is comparable to that of a house.

This volume of foam was used for 4 rows of masonry. The consumption for my perimeter is 8.5x9.5 m, taking into account the masonry of the inner wall - about 1.5 cylinders / row. Yes, the consumption is high, because a lot of glue-foam is needed in the grooves. Approximately 1.5 bags are consumed and mineral glue per row.

The foam gun does not reach the bottom row of masonry. You have to linger for a second when foaming. Squeezing foam out of a groove says the entire groove is well filled.

Foaming process video

Thanks to this hybrid method, laying is fast enough. And the use of a carriage for applying mineral glue to a horizontal surface further accelerates the process. There was an article about making a carriage here.

Why I don't use glue-foam on a horizontal surface - I'll tell you in the next article.

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Photos of the author (c)

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