ReinGlass Chopped Glass Fiber for Screed, Plaster, Dry Mixes

Q: How is ReinGlass different from ReinLite?

Both fibers work against shrinkage cracks. ReinGlass is stiffer, less visible on the surface and non-combustible. ReinLite is fully alkali-resistant.

Q: Will the fibers be visible on the surface after troweling?

No. Glass fiber filaments are very fine, and during mixing they separate and distribute evenly through the mortar. So the surface stays smooth after troweling, with no fuzz. Glass fiber doesn't interfere with painting, skim coating or tiling.

What is ReinGlass

ReinGlass is a chopped glass fiber with a diameter of 17 µm and a length of 6, 12, 18 or 24 mm. In the mix, it breaks down into thousands of individual filaments and forms a dense three-dimensional network. This network holds the mortar together in the first hours after placing, when rapid drying and settlement cause most cracks.

Glass fiber has a high modulus of elasticity, about three times higher than that of polypropylene. That’s why it holds fresh mortar more rigidly, doesn’t ball up and is almost invisible on the surface. The fibers are coated with an alkali-resistant sizing. ReinGlass doesn’t burn and is unaffected by UV light.

In concrete and cement-based mixes, ReinGlass works best where early crack resistance matters: in screeds, self-leveling floors and non-structural small precast units. For concrete floors that must perform for years and for heat-resistant concrete, ReinBasalt basalt fiber is the better choice, and for reinforcing slabs under load, choose ReinStrong macro fiber.

Specifications

Filament diameter	17 µm
Length	6 / 12 / 18 / 24 mm
Sizing	alkali-resistant
Tensile strength (filament)	3000 MPa
Modulus of elasticity	72 GPa
Density	2.55 g/cm³
Combustibility	non-combustible
Moisture content	< 0.5%

Technical data sheet (TDS) and quality certificate available on request.

Benefits

Fewer early-age cracks

Holds screeds, plasters and mortars together during early hardening, when most cracks appear.

Invisible on the surface

The fine fibers don't stick out or make the surface fuzzy, so they're suitable for finishing coats.

Stiff fiber

Glass has a modulus of elasticity about three times higher than polypropylene, so it resists plastic shrinkage and settlement better.

Non-combustible

Doesn't burn, rot or rust, and is unaffected by UV light.

For gypsum mixes

Gypsum contains no alkalis, so glass fiber retains its strength there without any limitations.

Good value

Direct-from-manufacturer pricing, no middlemen.

How and where to use ReinGlass

Where to use it

Sand-cement screeds and self-leveling floors
Plasters (cement and gypsum), skim coats
Dry construction mixes, tile adhesives
Gypsum products: decor, moldings, boards
Non-structural small precast units

Plasterer applying cement mortar to a block wall with a small trowel, holding a trowel loaded with mortar in the other hand

Recommended dosage

Application	Dosage
Screeds	0.6–1 kg/m³
Plasters, dry mixes	0.1–0.3% of the dry mix weight
Gypsum products	0.5–2% of the gypsum weight

The exact dosage depends on loads, thickness, concrete grade and subbase. We will match it to your project.

How to add it to concrete

Add the fiber to the dry mix or together with the sand and mix until it is evenly distributed.
Then add water and mix for another 2–3 min. Don't overmix, or the fibers will start to clump.
There is no need to change the mix design or the amount of water.
Safety: the fibers can cause temporary mechanical itching of the skin. Wear gloves, safety glasses and long sleeves.
Storage: in a dry place, in the original packaging.

ReinGlass documentation

Click a document to enlarge it.

ReinGlass FAQ

How is ReinGlass different from ReinLite?

Both fibers work against shrinkage cracks. ReinGlass is stiffer, less visible on the surface and non-combustible. ReinLite is fully alkali-resistant.

Will the fibers be visible on the surface after troweling?

No. Glass fiber filaments are very fine, and during mixing they separate and distribute evenly through the mortar. So the surface stays smooth after troweling, with no fuzz. Glass fiber doesn't interfere with painting, skim coating or tiling.

Become a ReinGlass distributor

We are looking for distributor partners in new markets and look forward to your request. Tell us about your company and market, and we will be glad to help with your order, the right fiber range and delivery to your country.