For all alkali bearing substrates, ie. Concrete, Shotcrete, Stucco, Mortar, etc. 
  • As a waterproofer, moisture vapour barrier, hardener, strengthener, or pH neutralizer.
  • As a pre-treatment or primer prior to the application of subsequent repair mortars, patching compounds, overlayments and secondary coatings. I.e. paints, adhesives, floor coverings, tile, epoxy, etc.

Surface Preparation
Concrete and masonry surfaces to be treated should be free of any cracks or defects greater than 1 to 2 mm(in width), and cleaned of any and all paint, laitance, dirt, dust, efflorescence, grease, grime etc., down to the bare concrete.
Once clean, the surface need to be dry prior to the application of Virobond 505. Ensure no puddles remain, remove excess water with mop or squeegee. Prepared surfaces should readily absorb Virobond 505. Test slab for absorbency.

Curing New Concrete
Virobond 505 applied during the curing stage slows down the concrete curing time while speeding up the setting time. The result is the reduction or elimination of hot spots and hairline cracking and surface checking due to spot drying. To achieve these benefits, apply Virobond 505 within 24 hours of starting the pour, after the surface sheen has disappeared, and the concrete can be walked on without leaving marks. Wetsack or cover the concrete within a tarp for a minimum 2 days.

Virobond 505 is pre-mixed at the factory, shake well before using to ensure maximum effectiveness.

Virobond 505 can be applied to dry surfaces, but is best applied to damp surfaces using a brush, mop, roller, or low pressure sprayer (max. 20-30 psi). Ensure there is no standing or running water on surfaces to be treated. Be aware of surfaces temperature. If the concrete of substrate is too warm, (l.e. warm to the touch), evaporation will reduce the amount of Virobond 505 available to penetrate into the substrate. To ensure a minimum of product lost to evaporation, pre-wet or soak all areas to be treated with water, spread out or mop up any puddles, begin application when the surface has dried to the “damp” stage. Apply Virobond 505 liberally (at minimum the predetermined coverage rate) and saturate all areas. Each spray swath should overlap the previous one by half it’s width. To ensure full saturation, check areas 15 to 20 minutes after application for areas which appear to be drying faster. Apply Virobond 505 again over these area at the same rate of spray. Do not leave puddles of Virobond 505 on surfaces. Use a mop squeegee to spread or remove any puddles. Apply Virobond 505 as per above twice. I.E. Apply until concrete is wet and shiny, soaking areas again within 15 minutes where the Virobond 505 is sucked into concrete most quickly. Wait 1 hour repeat as per above.

Procedure for Determining Coverage and Application Effectiveness
Three to four days after the application of Virobond 505, the surface should be thoroughly flushed with clean water, to remove any alkali or contaminants that Virobond 505 pushed to the surface. Then allow to dry. ASTM 4263 “Sponge” Test Procedure : (Check moisture vapour transmission) Tape several 12″ square pieces of poly or foam rubber to the dry substrate. Leave for 24 hours, then remove. If the poly or the substrate beneath is wet, an additional application is required. Apply application coats in the same manner as the first coat and allow to dry. Flush with clean water, allow to dry and sponge test (as required) to determine the need for an additional application. If a third coat is necessary, dilute Virobond 505 1:2 with clean water.
Note : Examples of highly contaminated substrates which may require multiple applications include steps, sidewalks, driveways, etc. When flushing with clean water to remove all salts, or contaminants which have been pushed to the surface, Virobond 505 may penetrate deeper into the substrate resulting in more contaminants being forced to the surface. In very extreme cases, cycles of daily flushing and drying for up to 3 to 7 days may be necessary before no further contaminants appear on the surface after drying. When rinsing no longer flushes anything to the surface and the sponge test reveal no moisture; no further application of Virobond 505 is required. The treated and flushed surface should be allowed to thoroughly dry for a minimum of 24 hours prior to the application of any subsequent coatings.

On vertical, formed surfaces
Apply Virobond 505 as soon as the forms have been stripped and the surface rubbed, (if required). Apply from the bottom up, going over the area twice to ensure full saturation.

Back-filling foundations
12 hours after application.

Foot traffic
Within 4 hours of application or when surface appears dry.

On overhead surfaces
Apply with a low pressure sprayer using multiple light applications as required. The first application should only wet the surface. Do not saturate as dripping will occur.

Application over Repair Mortar, Patches and Overlays
Follow the same surface preparation and application procedures as shown previously. Application onto polymer modified repair mortars, patches and overlays will not penetrate as deeply as non-polymerized, alkali substrates, but will increase surface hardness, dust-proofing performance including the bond strength of subsequent coatings.

Packaging Standards
  • 5 Litres Pail
  • 20 Litres Pail

Virobond 505 should not be applied if the ambient temperature is expected to fall below freezing, (0 degrees Celsius) within 24 hours of application. Do not apply Virobond 505 to any non-alkali bearing material, glass, glazed surfaces or aluminum, as “etching” will occur. Use protective coverings to ensure no over spray or wind carried contact with these surfaces occurs. In case of accidental contact, rinse immediately with water. Freezing will not harm the Virobond 505. If frozen, thaw out completely, shake well and fully remix prior to using.

Virobond 505 is not a stain blocker. Although properly treated surfaces will not allow penetration of liquid materials below the top 1/2 mm of the surface, staining may still occur. Therefore, if a higher stain resistance is required, the application of an additional coating to fill that top 1 mm such as Virobond 515 (Penetrating Top Layer Seal), should be considered over the Virobond 505 treated surfaces. Contact our technical support department for more details of using these products. Most of the benefits of applying Virobond 505 are permanent. Virobond 505 is a sealer, hardener, pH neutralizer, moisture vapour barrier and more. Virobond 505 works below the surface by permanent replacing.

Virobond 505 contains unique, propriety catalysts, which allow the following reaction to take place :

  • The water-based Virobond 505 will penetrate below the surface of the concrete or masonry where it will encounter a CH (Calcium Hydroxide) rich environment.

  • Upon contact with the alkali (lime) and CH (Calcium Hydroxide) within, the Virobond 505 will instantly react to form aero-silica gel membrane within the voids below the surface of the concrete, masonry or alkaline substrate. This gel alone will often waterproof the substrate. However;
  • Over 3 to 7 days. this gel membrane will hydrate, hardening into CSH (Calcium Silicate Hydrate), providing a permanent, internal, seal and moisture barrier, as well as increased surface hardness, dusting resistance, and dramatically increased compressive strength.
  • Waterproofing, hardening and vapour-proofing for all old or new concrete, shortcrete, stucco, mortar, etc.

  • A pre-treatment prior to patching or overlaying concrete for the purpose of waterproofing, hardening and moisture vapour-proofing the substrate, or pre-treatment prior to painting, installing a floor covering, hardwood, or secondary coating, epoxy, urethane, polyurethane, etc.

Surface Preparation – Old Concrete
Surface to be treated must be free of any cracks or defects greater than 1 mm. (in diameter), and cleaned of any and all materials; laitance, dirt, dust, grease, grime, etc., down to the bare concrete or substrate.

Greasy, oily, or acidic conditions, will require appropriate cleaning in advance of and prior to the application of Virobond 505. Scrubbing with a floor buffer and stripping pads, chemicals, acids, high pressure hot water, or other means may required to get down to bare substrate. To test readiness sprinkle water on the surface, if water drops bead up and are not readily absorbed by the concrete, the surface is (still) coated or contaminated by an organic compound which must be removed. Tight, power towelled floors may require surface abrasion.

Once clean, the surface need not to be dry prior to the application of Virobond 505, but ensure no puddles or any visible water on the surface. If so, remove excess water with mop, etc.

The untreated old concrete will still needs to be cleaned down to the bare concrete prior to application of Virobond 505. Follow the usual site preparation and surface readiness testing procedures, as required, i.e. Water absorption test.

Surface Preparation – New Concrete
Curing – The silica gels formed when Virobond 505 is applied, will as they hydrate slow down the curing time while speeding up the setting time of the concrete. The result is the reduction of elimination of hot spots and the hairline cracking and surface checking due to spot drying.

To achieve these “curing” benefits, apply Virobond 505 within 24 hours of starting the pour, but, no sooner than when the concrete has set, the shiney, surface sheen has disappeared, and the concrete can be walked on without leaving any marks.

Appropriate coverage rates when applying Virobond 505 for this purpose can vary from approximately 1.5 to 3.0 sq. Meter per litre, (if you apply the Virobond 505 towards the end of the allowable 24 hours after the start of the pour. Pro-rate coverage and application rates accordingly, depending on when Virobond 505 is applied during this period.

Application Equipment
Brush, mop, roller, will work, but the best way is a Low Pressure Sprayer (max. 20-30 psi).

Virobond 505is a pre-mixed solution st the factory. Shake it well before using it, this agitation will ensue the maximum effectiveness.
The particular viscosity of Virobond 505 has been developed to allow the applicator to successfully complete most applications to most substrate, in the shortest possible application time, usually with one coat. Thinning Virobond 505 will enable it to “go deeper, faster”, but more applications will be necessary to ensure Virobond 505 maximum effectiveness.

Do not dilute or mix Virobond 505 with water or any other liquid. Use only as supplied. However, there are occasional exceptions :

  • You might have an application to a substrate at the extreme edge of the low porosity/high surface tension scale, l.e. Some power towelled floors, or some second and third coat Virobond 505 applications.

  • You might have surface temperature high enough to cause evaporation of the water in the Virobond 505 before the Virobond 505 can all penetrate.

In such low porosity/absorption or high surface temperature situations, Virobond 505 diluted with potable water, 1:1 to 1:2, may better serve the purpose.
Note : Even if diluted on occasion for such an application, ensure Virobond 505 is applied as usual, with as many coats as necessary, until the concrete or substrate successfully passes the ASTM “sponge” or moisture transmission test as described in this Spec.

Predetermine the Coverage Rate
It is always recommended to predetermine coverage rates; Conduct a small scale test in an out-of-the-way corner of the area to be treated following the application instructions below. Pro-rate the estimate accordingly. If ensure of any aspect of a potential or actual application, please consult your dealer or distributor or email to us at [email protected]