QUESTIONS AND ANSWERS ABOUT
USING WATERPROOFING PRODUCTS
An MS Polymer such as T-Rex or equivalent adhesive should be used to ensure proper adhesion.
For most applications, you can use Gripset 51 as your primer, by mixing 1 part Gripset 51 to 3 parts water. Once dry, you can then apply the first coat of Gripset 51 (undiluted).
One option is to apply a clear penetrative sealer such as Driwal P6 onto the tiles and grout. Remove any excess sealer that is not absorbed with a cloth as you work. The sealer will penetrate into the grout (and tiles if they are porous), making the area water repellant. It is of note that any cracked grout or tiles must be either repaired or replaced prior to work taking place.
The first coat must be applied using a brush. The second coat may be applied by either brush or trowel.
The basic Ultra Flex is considered to be a lightly trafficable membrane, whilst Ultra Flex Traffic is a medium to heavy duty membrane. Either product may be top coated with a trafficable coating such as Deckgrip or Ultra Tuff to increase the durability and provide for a non-slip coloured surface.
- Ambient temperature
- Temperature of substrate
- Water content of substrate
- Air flow
- Thickness of the membrane
- Type of membrane used
After the time specified by the manufacturer, check the primer by touching it. If the primer is dry then it is ready for the first coat of membrane. Drying times can vary depending on multiple factors not least of which is the specific primer used.
A Crystal Sealer is a cementitious Construction Chemicals product designed to be applied to concrete which is leaking water. In time it will grow crystals into the concrete following the water paths through the concrete capillaries and eventually waterproofing said concrete. It is applied by brush in approximately 2-3 coats and then requires watering once every 24 hours for three days for maximum effectiveness.
An epoxy primer should be used under a number of circumstances, including when working over uncured cement based products as well as on substrates that may be saturated with water after bad weather. It can also be used to prime substrates (such as PVC and Scyon) that may normally be very difficult to adhere waterproof membranes to using conventional water based primers.
Solvent based membranes generally require that the substrate be perfectly dry prior to application of the membrane or an epoxy primer should be used if the substrate is damp. Solvent based membranes also contain Isocyanates which can be detrimental to human health and the applicator should wear appropriate breathing apparatus whilst working with them. Tiling on solvent based membranes can also be difficult, and it is recommended that the data sheet is referred to prior to tiling to prevent adhesion failure.
Most waterproof membranes have specific primers which are manufactured for use with them. In certain circumstances alternative primers need to be used such as epoxy, and you should consult the product data sheet or your waterproofing experts if in doubt.
It is important to note that just because a screed is touch dry, does not mean that it is ready for an application of waterproofing product over the top of it. A screed has to be fully cured, prior to membrane application, and that can vary dramatically due to a number of factors, including thickness of the screed, specific mixture of the screed, humidity, air flow and temperatures amongst other things.
As a very general rule of thumb, you should wait a bare minimum of 24 hours for every 10mm of screed thickness or a minimum of 72 hours for screeds thinner than 30mm. This is a basic guideline only, and in reality screed curing times have varied wildly; in some extreme cases taking up to 30 days to fully cure.
If in any doubt whatsoever as to the curing status of the screed, always use an epoxy as a vapor barrier prior to membrane application.