Silicone Spray Render

APPLICATION GUIDE

WBS SILICONE SPRAY RENDER

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WBS Spray Render is a cement based, polymer modified, self coloured render, requiring only the addition of water and 10 minutes mixing time. If applied as per manufacturer’s instructions, WBS Spray Render will provide an attractive, low maintenance finish.

WBS Spray Render is designed as a one-coat finish over blockwork. Coverage may be reduced if hand applied.

Apply: 16-22mm thick
Coverage: 1.8kg/mm thick/sq m.
Req: 25-35kg/sq m

WBS Spray Render is normally applied in two passes depending on background conditions and final finish required.

It is important that a consistent minimum finished thickness is achieved over the whole surface and that the maximum recommended thicknesses are not exceeded.

APPLICATION

WBS Spray Render may be applied by projection machine (P11, P13, Rasi, Mixijet, M-Tec or other suitable machine). Minimum pressure 11 BAR.

Mix for at least 10 minutes in mixing section of machine to ensure breakdown of resins. Open time approximately one hour.

Add 4 - 5 litres of clean water per 25kg bag.

Do not polish.

Small areas such as quoins and window reveals may be finished smooth.

Use polythene sheeting to protect doors, windows and other features from any over-spraying during application.

FIRST PASS

Using 12mm or 14mm diameter mortar nozzle, spray, apply WBS Spray Render directly onto the prepared wall surface to the required thickness of
4-8mm.

Level out immediately, using a darby, straight edge, smoothing trowel or float.

Allow the first pass to stiffen before applying the second pass, the time between passes being shorter in warm dry conditions, and much longer in extreme wet conditions.

SECOND PASS

Use a 8mm or 14mm diameter spray nozzle according to the finish required.

The normal recommended finished thickness of most finishes is between 12-14mm.

FINISHES

Textured Finish

To achieve a textured finish, scraping should take place when the render has set but not hardened.

The exact timing of this operation will vary according to the weather conditions.

The surface is ready when a thumb impression cannot be made and when the aggregate scrapes easily from the matrix without sticking to the scraper.

Scraping should be done in a tight circular motion, and the surface brushed down with a soft brush upon completion.

All areas must be scraped at the same stage of readiness, as early scraping will result in darker shades and late scraping in lighter shades.

A uniform approach is essential to achieve an even finish.

Ashlar Cutting

Having scraped the surface level, an ashlar effect may be achieved by cutting into the surface with an ashlar cutter to form grooves.

Leave a minimum 10mm of coloured render between the recessed ashlar cut and the substrate.

When forming cuts take care to avoid damaging the arrises by working away from the external corner.

All cuts must be the same width and depth and set out uniformly as required.

Dry Dash Finish

Apply a butter coat of render to a uniform thickness, depending on the aggregate size.

While the render is still plastic, throw washed aggregate on to the surface to give a uniform dense coverage.

Immediately, lightly tamp the aggregate particles lightly into the butter coat with a wood float and ensure a good bond is obtained.

Tyrolean Finish

The WBS Spray Renderd mixture is applied in light sprays from a tyrolean gun, passing in an arc from 45° left to 45° right, and returning over the same area.

Each pass will apply approximately 2kgs per square metre, with a thickness of 1.5mm per pass. A minimum coating thickness of 4mm with a weight of 5kgs per square metre is usually necessary to achieve a good density of coverage.

Provided strictly for guidance purposes only. For technical support please call 08458 382380.