Poroton plastering - what is important?

Poroton walls are basically considered brickwork. Therefore, what has to be considered when plastering inside and outside, which regulations the DIN makes, and what additional measures may be required, informs this guide.

Rules for plastering

The regulations of DIN 105 / EN 771-1 and, if applicable, the general DIN regulations regarding plaster mortar and its processing apply fundamentally to the professional plastering of brick masonry.

In particular, the suitability of individual plaster mortar for the brick substrate is here to pay attention.

Poroton plastering - what is important?: plaster

Special features of Poroton

Outside, Poroton needs a so-called burn-up barrier. This must be painted on all bonded Porotonsteinen - including those with thermal insulation - before plastering and dry accordingly.

It prevents the brick from quickly draining moisture from the plaster and "burns" it.

In the interior, a primer is also highly recommended, so that the plaster keeps better on Porotonwänden. To what extent a burn-up barrier is also necessary, must be assessed on the spot using the respective object.

Suitable plasters

For Porotonziegel - which are a special lightweight construction material - lime cement plaster is not suitable. Only light plaster may be used here. Plasters based on gypsum or lime are also well suited for Poroton, as long as they are designed as light plaster.

In the outdoor area, plaster heights of 0.5 cm to 1 cm can be sufficient in many cases. As a result, the surface load is kept low. Which plaster can be used in detail, however, must again be decided on an individual basis on the basis of the circumstances of the object.

Pre-grout and Spritzbewurf

Neither pre-mortar nor spray guns should be carried out on Porotonsteinen. They increase the weight per unit area and are usually not necessary for easy-clean plaster adhesion.

An accusation with very thin plaster shortly before the plastering is recommended by some craft enterprises. With the main plaster should be maintained until the litter plaster has a plasticine-like consistency. This should help to avoid cracking in the main plaster.

Due to the very low plaster strength, however, the risk of cracking is very low. Pre-wetting of the wall for uniform, full-surface plaster adhesion and uniform, crack-free drying is certainly sufficient in the majority of cases.

Tips & Tricks

A burn-in barrier may also be necessary with other lightweight materials before plastering on the outside: for example, Ytong or sand-lime brick.

Video Board: Rendering corners by hand on cement block walls