LVL Handbook EUROPE

1. LVL AS A CONSTRUCTIONMATERIAL

1.12.8 Surface coating of LVL

LVL can be painted with fully pigmented non-transparent

paints or stained with translucent stain or varnish. Due to

peeling cracks, the surface of LVL is more demanding to paint

than, e.g., solid wood. The cracks occur in the face veneers as

a result of contraction and swelling of the product. In indoor

conditions these cracks are not usually problematic, but in ap-

plications exposed to weather, a pigmented covering paint is

required to protect the LVL. If the moisture nevertheless pen-

etrates the LVL member, for example at the penetration points

of connectors, at the edges or other similar areas, a thick paint

coating will tend to flake. This is especially evident on large

continuous surfaces. If surface cracks are not problematic for

the application in question, a light non-film-forming surface

treatment can be a suitable alternative. This may require more

frequent maintenance, but the maintenance treatment is eas-

ier to perform.

The durability of the coating depends on various factors:

the base material and how it has been prepared; the level of

Figure 1.66.

Coated surfaces of LVL beams.

exposure to sunlight; the colour and darkness of the coating;

and the level of exposure to moisture. General guidelines for

coating LVL:

• Apply the coating as soon as possible to prevent the effects

of UV radiation on the wood surface. If needed, sand the

surface prior to coating.

• Fill any voids, such as fallen knots, with substitute wood

compound.

• Choose a primer with blue stain and mould protection.

• Round the edges of the member slightly to ensure adher-

ence of an adequate thickness of coating also on the edg-

es. Edge coating is especially important for all veneer-based

wood products.

• Apply the coating agent to an adequate thickness. Apply the

coating agent in at least two layers to ensure proper drying

of the layers.

In all cases of coating LVL the application should be discussed

in detail with the coating agent manufacturer to ensure the

suitability of the product for the application

Stora Enso

LVL Handbook Europe