Lightly corrosive environment (ORTHO)

Intergrate® ORTHO GRP gratings are produced with a high-quality patented orthophthalic polyester resin combined with a continuously woven fiberglass pattern. There are two types of ORTHO resin:


Types of resin

When choosing the type of resin, you need to determine whether the grating must be fire-resistant. You can choose between:

    • ORTHO-NFR is a polyester resin that provides good protection from atmospheric corrosion. However, it is not fire-resistant. The abbreviation NFR stands for ‘Non fire-retardant’.
    • ORTHO-FR is a polyester resin that provides good protection from atmospheric corrosion. This type of resin is also fire-resistant (high-quality fire-retardant). This type of polyester resin has a flame propagation index of 25 and a smoke index of 800 in accordance with the ASTM E-84 tunnel test. The abbreviation FR stands for ‘fire-retardant’.

Anti-slip class

As standard, all Fiberstruct GRP gratings are produced with an anti-slip class in accordance with BGR 181 and DIN 51130. The slip-resistance of surfaces is categorised in anti-slip classes. These GRP gratings satisfy anti-slip class R13 (greater than 35°, extremely high coefficient of friction).

Class      Angle of inclination
R 9 6° - 10°, low coefficient of friction
R 10 > 10° - 19°, normal coefficient of friction
R 11 > 19° - 27°, good coefficient of friction
R 12 > 27° - 35°, high coefficient of friction
R 13 > 35°, very high coefficient of friction

Available mesh widths

Fiberstruct GRP gratings are available in the following thicknesses and mesh widths:

Grating thickness

(in mm)

Grating mesh width (in mm)


 Gratins mesh width inside

(in mm)

13 51 x 51 45 x 45
25/30/38 38 x 38 32 x 32
30/38 Micromesh      19 x 19 13 x 13
51 51 x 51 43 x 43

RAL colours

  • As standard, ORTHO-NFR GRP gratings are provided in the colour grey RAL 9006 (other colours on request).
  • As standard, ORTHO-FR GRP gratings are provided in the colour grey RAL 7040 (other colours on request).
A new office Our new office at Industrieweg 32 in Terneuzen is almost finished and our GRP gratings cannot be missed of course! We will move to the new office by the end of this year.
Project reservoir Africa Fiberstruct has recently succeeded in providing a total GRP solution for an important reservoir in Africa. We supplied GRP gratings and ladders with anti-slip and GRP railings Another great collaboration abroad!