Internal
walls can be plastered all year round, even in winter. All you need to do is
remember a few rules to avoid unpleasant surprises in the form of cracked or
peeling plasters or discoloration. The final shape, color and appearance of
internal walls and ceilings depend primarily on the plastering work. It is an
important and integral element of construction works, both during the
construction and general renovation of a house or flat.
When
can you plaster?
We
can start work after the period of settling and shrinkage of the walls, ie
optimally from 3 to 6 months after completion of work on the unfinished state. At
this time, the building should initially settle. Concrete and concrete
substrates require waiting for at least 2 months. Also note that plastering of
the walls requires certain atmospheric conditions: should not be plastered at a
temperature lower than 5
° C and
above 25
° C.
A lower temperature would lead to the freezing of the plaster, which in
turn, leads to its uneven drying out and
discoloration. On the other hand, work on dry and sun-warmed walls should be
avoided during the summer.
How
to prepare the substrate?
Proper
preparation of the substrate is an important element of plastering work. The
ideal wall should be even, dry
and
not dusty. It is also important that it is rough and evenly absorbs water and
that the substrate is free of efflorescence and free of scratches and cracks. All
unevenness and dirt should be removed before starting work - only such
conditions will guarantee us optimal plastering results. Remember to cover and
attach, for example with a steel mesh, all metal and wooden elements. Metal
elements must be additionally protected with anti-corrosive agents. What is
important, in the case when the substrate under the plaster is extremely
absorbent, such as cellular concrete or silicate blocks, it is recommended to
make (for a well moistened wall surface) mortar made of, for example, cement
Lepo Lafarge and sand in the proportions 1: 1. Such a treatment will
significantly reduce its absorption.
What
to remember when preparing the mortar?
The
basis of plastering mortar is the appropriate selection of the proportions of
individual components, so that it obtains the right consistency. For the mortar
to meet all requirements, always use good quality ingredients. When you earn
it, remember to mix the right order - cement, sand and 2/3 of the water are
mixed first. Then slowly add the rest of the water until the required
consistency. It should be remembered that the ready mortar maintains its
properties for about 3 hours. After this time, it should be unconditionally
discarded. It is also unacceptable to add water for reuse. This threatens the
insufficient strength of the plaster, and thus its damage, cracking and falling
away.
How
to plaster?
The
key element is proper preparation of the plaster mix. It must be chosen in
complete agreement with
the design and technical specification. The recommendations placed on the
cement packaging must also be taken into account. It should be remembered that
the plaster profiles must be selected in accordance with their future function
and that no empty space can be allowed behind them. In addition, plastering
netting must be applied to all areas exposed to cracks in accordance with the
technical specification. The thickness of the finished plaster depends on many
factors: the substrate, the mix itself, the way it is made, as well as the
number of layers.
We
can distinguish the subsequent stages of laying various types of plasters:
-
making the casting of a rare mortar with a thickness of 3 - 4
mm .
The consistency of the coating should correspond to a 10 -12 cm draft
of the measuring cone;
-
after a slight curing of the coating, a coating of 8 - 15
mm is made .
The mortar density should not exceed 9
cm immersion
of the measuring cone;
-
the next layer is made of thin mortar with fine sand with a grain size below 0.
25 - 0.
5 mm .
The mortar should be more "oily" than the topping, while the
thickness of the coat is usually 1 - 3
mm .
After concentrating the finishing coat, it is rubbed with a wooden, steel or
felt-covered wooden packet, depending on the type of plaster finish.
Cement
recommended for plastering mortars
Lepo
is a masonry cement that does not require the addition of lime or plasticizers.
It was developed for mortar masonry and
plastering, it is also perfect for finishing works, for example leveling the
floor under the floor, or other minor renovations. It is characterized by good
adhesion to the substrate and high workability, thanks to which it accelerates
the pace of construction, reduces executive costs and material losses arising
during masonry and plastering works.
