Masonry Treatments

Silicone-based water repellents from MBI Silicones extend for years the life of a broad range of masonry substrates including brick, concrete, stone and wood. They provide a variety of unique benefits like water vapor permeability, clear and non-tacky finish, reduced efflorescence, reduced dirt deposition and also reduced freeze-thaw damage.

The group of MBI Silicones masonry water repellent products consisting of ready to use and dilutable concentrates can be easily applied to masonry surfaces by dipping, spraying or brushing to confer durable protection and weather resistance to treated substrates as well as improved thermal insulation to building walls.

MBI Silicones masonry water repellents can be classified as follows:

A. Water repellents for concrete
Newly formed concrete requires silane treatment. MBI Silicones recommended silane treatments are:
1. Solvent based SWR20 and SWR40 silanes
2. Water based MWR12 and MWR50 silane/siloxane emulsions
3. Solvent based silane/siloxane concentrates SFS-104, SFS-104A and SFS-105
The high alkalinity of the substrate will provide an accelerated cure of the silane, with no change in substrate appearance after applications. Silanes can be applied to damp surfaces although dry surfaces are preferred to achieve maximum penetration. Silanes will cure with moisture present in the air and give off an alcohol by-product that evaporates into the air.

The recommended treatment for aged concrete, with reduced alkalinity are the siliconate solutions, like MBI Silicones SFS-151M. Siliconates are alkaline materials and therefore do not require a catalyst to cure like silanes and can be used on a wider variety of substrates. SFS-151M is supplied as a concentrate and is effective on substrates when applied at 3-5 % solids. The solvent and water based silane/siloxane blends also provide a tough water repellent film against salts blooming and wind driven rain.

B. Water repellents for brick
Most of the brick substrates are neutral and water based siliconate like SFS-151M is again very effective when applied at 3% solids or less. Over application of siliconates will cause surface whitening. Great care should also be taken to protect nearby vegetation or other articles from over spray, due to siliconates high alkaline character. Much more easy to handle and environmentally friendly, MWR50 silane/siloxane emulsion proved highly effective at 5-20% solids on brick and stone surfaces, as well as MWR12 ready to use emulsion.

Solvent based silane/siloxane blends as SFS-104, SFS-104A or SFS-105 may be successfully used on alkaline and non-alkaline substrates at 5-6% solids to impart excellent water repellency.

C. Water repellents for wood
MWRB3 is a 20% actives organosilicone emulsion initially designed for wood water repellency. It would provide water exclusion, dimensional stability and water beading to any unpainted wood that needs protection from moisture.

The tables below summarize the applications and properties of MBI Silicones Masonry Water Repellents.

Masonry water repellents typical properties

Masonry Water Repellents application guide

●● Primary recommendation
● Alternative recommendation