Mick's Notes
Tech-Dry® Stabilised Earth Water Repellent W is a clear penetrating water-based silicone water repellent sealer for external rammed earth walls.
Stabilised Earth Water Repellent W is highly recommended if your existing rammed earth wall does NOT have Plasticure or any other waterproofing admixture or sealer added to it.
This sealer needs to be re-applied as maintenance to a RE wall (2-5 yrs depending on exposure).
Although it is not necessary to apply a sealer if Plasticure is used, we recommend that you spray Stabilised Earth Water Repellent W after your exterior walls are built to help protect them from any visible run marks or construction stains (nail rust and spills etc), and weathering.
Stabilised Earth Water Repellent W dries to a clear matte finish. As this product is penetrating, there is no film/coating present after application so the wall can still breathe.
Please see Aussie Built's Rammed Earth Sealing Process for superior wall preservation and presentation.
Description
Tech-Dry® Stabilised Earth Water Repellent W is a water-based silane/siloxane emulsion water repellent for stabilized earth or rammed earth structures.
The product is designed to penetrate into the capillaries and render the substrate water repellent. This, in turn, reduces the presence of efflorescence and other water-borne staining materials which are responsible for the majority of the deterioration in earth building materials. It is a clear drying sealer and will not significantly change the surface appearance and vapor permeability. However, a slight darkening of the surface may occur.
Recommended Uses:
Stabilized Earth Water Repellent W is recommended as a water repellent sealer for stabilized earth or rammed earth buildings. It may be also suitable for other porous masonry substrates. Some of the important features of this product include:
- Penetrates into the substrate surface.
- Permanently bonds to the substrate with no peel or blister.
- UV, alkali stable, and durable formulation.
- Reduces water penetration, efflorescence, and water-borne staining.
- Does not significantly change the surface appearance and vapor permeability.
- Water-based environmentally friendly formulation and easy application.
As masonry materials vary significantly, a test MUST be carried out prior to application to find out the suitability of this product for the purpose.
Due to the difference in temperatures (internal vs external), it is very important with any earth structure (rammed earth, mud brick, adobe) that the external perimeter walls are left breathable without any coating film applied. On the other hand, it is okay for internal walls, where both sides of the wall are internal within the property, to have a coating applied as the temperature is constant.
Dosage
Stabilised Earth Water Repellent W should be shaken before use.
- The consumption of Stabilised Earth Water Repellent W depends significantly on the permeability of the substrate.
- Stabilised Earth Water Repellent W must first be diluted 1:9 before application.
- 5 gallons (20lt) of concentrate diluted at 1:9 will produce 50 gallons (200lt) of ready-to-use external sealer.
- 50 gallons (200lt) of diluted, ready to use Stabilised Earth Water Repellent W will cover approximately 7,500 sq.ft of rammed earth surface (wet-on-wet).
- 1 gallon diluted Stabilised Earth Water Repellent W will cover approximately 150 sq.ft of rammed earth earth surface (wet-on-wet).
Instructions
Before application
The surface to be treated should be dry, firm and free from grime, oil or any previous coatings/sealers. Please see Aussie Built's Rammed Earth Sealing Process for how to clean your walls.
All cracks should be properly filled and allowed to cure before application. Don’t apply if rain or extreme weather conditions are expected and/or the temperature is below 50°F. Opalescent (milky) appearance may occur if the temperature is below 50°F or if the fresh coating film is in contact with water during application and drying. Close the container as soon as possible so the remaining sealer within the container avoids possible skin formation.
Application
- Stabilised Earth Water Repellent W should be stirred before use.
- The sealer should be diluted with clean tap water at a range of 1 part Stabilised Earth Water Repellent W to 9 parts water before use.
- 1 gallon of diluted Stabilised Earth Water Repellent W will cover approximately 100 sq/ft of rammed earth surface (wet-on-wet).
- Can be applied using a brush, roller or spray. However, the product is preferably applied by using a hand pressure spray or airless spray equipment. The sealer should be applied as a liquid thin film stream that runs down the surface. A second application should follow immediately after the first coat is absorbed by the surface while the wall is still wet. This is termed a "wet-on-wet” application. The object is to saturate the surface to allow better penetration. The emulsion should soak into the earth surface leaving the wall with a matte, wet appearance. On drying, there should be little discernible color change.
- The number of coats depends on the permeability of the substrate. For very permeable substrates, more coats may be required. If necessary, allow the sealer to dry before further coats.
- Avoid any excessive accumulation of the sealer or runs by backrolling the wall with a ½” nap roller to avoid streaking or an uneven finish.
- Don’t spray the product onto any area you don’t wish to treat. If splashing occurs, the product should be removed with a damp cloth before the sealer dries.
After application
The initial surface water repellency may develop immediately after the sealer is
absorbed. Full curing may take 24 hours or up to 7 days. Avoid heavy traffic or
any staining for at least 24 hours. The equipment can be washed in water.
For dusty or crumbling external rammed earth walls:
Stabilized Earth Water Repellant-W can be applied in conjunction with Earth Binder providing excellent water repellent and dust sealing properties to a loose surface.