Waterproofing of pools and painting with epoxy coating
RELATED MATERIALS
EPOXYCOAT-S Two-component epoxy coating suitable for swimming pools
DUROFLOOR-BI Two-component, colorless epoxy impregnation
ADINOL-DM Waterproofing admixture for mortars and non-reinforced concrete
ADIPLAST Polymer latex for multiple improvements of mortars
PLASTIPROOF Plasticizing/water reducing admixture for concrete
EPOMAX-EK Two-component epoxy putty
SM-14 Special solvent for epoxy coatings
I. NATURE OF THE PROBLEM – REQUIREMENTS
A usual and affordable way to prepare the final surface of a swimming pool is to paint it with a special paint, such as an epoxy coating. This is a technically efficient solution that is clearly more affordable than overlaying with ceramic tiles.
The choice of using epoxy coating affects significantly the selection of the means for waterproofing the pool, since it sets specific requirements for the waterproofing that will be carried out.
More specifically, the waterproofing layer must:
Be long lasting, since its position between the pool’s structural elements and the layer of the epoxy coating makes future interventions difficult and expensive.
Bond well to the pool’s structural elements, in order to withstand negative pressure that may develop on it periodically.
Have a smooth surface.
The coating to be used must have the following properties:
Elasticity, in order not to crack from possible expansions and contractions.
Resistance to water and chemicals that may be present in the pool water (e.g. chlorine).
Resistance to weather effects (e.g. solar radiation, frost etc.).
II. SOLUTION
The primary requirement is that the pool’s frame must have been calculated properly so that it can withstand the water’s hydrostatic pressure successfully.
Waterproofing of the pool is achieved efficiently by applying a strong waterproof cement mortar to the pool’s walls and bottom, which acts as a sealing and smoothing layer at the same time. Thus, the smooth, stable and waterproof substrate needed for the application of the epoxy coating is created.
This cement mortar becomes waterproof with the addition of ΑDINOL-DM waterproofing admixture, in a proportion of 1% of the cement weight.
Its bonding to the pool’s walls is ensured by the application of a spatterdash reinforced with ADIPLAST polymer latex, while its bonding to the bottom is ensured by the application of a bonding layer reinforced with ADIPLAST, as well.
Moreover,it is recommended that during the concreting of the pool’s structural elements, PLASTIPROOF concrete waterproofing admixture is added to the concrete, in the proportion of 0,2-0,5% of the cement weight.
The requirements of elasticity and resistance to chemicals that the coating must satisfy are met successfully by the application of EPOXYCOAT-S epoxy coating. This is a 2-component epoxy system that displays increased elasticity and resistance to friction. Furthermore, it is especially resistant to a variety of chemicals, such as diluted acids, alkalis, petroleum products, some solvents, water, sea water, and to weather effects.
III. APPLICATION
Substrate preparation
The substrate should be cleaned thoroughly of grease residues, deshuttering agents, loose materials, dust etc.
Exceeding construction forks should be cut up to the surface of the wall.
A strong, waterproof undercoat layer of a cement mortar (cement : sand = 1 : 2,5) should be prepared, with the addition of ADINOL-DM waterproofing admixture, in a proportion of 1% of the cement’s weight.
The bonding of the cement mortar to vertical surfaces is reinforced by the application of a spatterdash with the addition of ADIPLAST polymer latex (cement : sand : ADIPLAST : water = 1 : 1 : 0,25 : 0,25 parts by volume).
The cement mortar’s bonding to the bottom of the pool is reinforced by applying a bonding layer with the addition of ADIPLAST (cement : sand : ADIPLAST : water = 1 : 1 : 0,5 : 0,5 parts by volume).
The undercoat layer should be applied with the aid of guiding beams at a thickness of 2-3 cm.
Consumption of ADINOL-DM: approx. 4,2 kg/m3 of cement mortar.A strong, waterproof finishing layer of a cement mortar should be prepared, with the use of fine-graded sand (cement : sand = 1 : 2) to which ADINOL-DM waterproofing admixture is added, in a proportion of 1% of the cement’s weight.
The cement mortar should be applied at a thickness of 5-10 mm and then rubbed with a sponge float.
Consumption of ADINOL-DM: about 5 kg/m3 of cement mortar.At the intersection of the walls and bottom of the pool, and where walls meet, it is recommended that a groove is formed during the application of the cement mortar, in order to facilitate the subsequent application of the epoxy products.
Priming and painting with EPOXYCOAT-S epoxy paint
At least 28 days after the application of the cement mortar, time which is required for it’s hardening, and as long as it is dry (moisture < 4%), the surface of the pool's bottom and walls should be primed with DUROFLOOR-BΙ.
Components A (resin) and B (hardener) are packed in two separate containers, having the correct predetermined mixing proportion by weight. The whole quantity of component B is added into component A. Mixing of the 2 components should take place for about 5 minutes, using a low revolution mixer (300 rpm). It is important to stir thoroughly the mixture near the sides and bottom of the container, to succeed uniform dispersion of the hardener.
Consumption of DUROFLOOR-BI: about 150 g/m2, depending on the substrate’s absorptivity.
Alternatively, priming may be done with EPOXYCOAT-S diluted 10% to 20% with SM-14 special thinner.Any cracks or imperfections should be filled in with EPOMAX-EK epoxy putty.
After the primer dries, and within 24 hours of its application, the pool should be painted with EPOXYCOAT-S epoxy coating.
Components A (resin) and B (hardener) are packed in two separate containers, having the correct predetermined mixing proportion by weight. The whole quantity of component B is added into component A. Mixing of the 2 components should take place for about 5 minutes, using a low revolution mixer (300 rpm). It is important to stir thoroughly the mixture near the sides and bottom of the container, to succeed uniform dispersion of the hardener.
EPOXYCOAT-S may be applied as it is or diluted up to 10% by weight with SM-14 special thinner with a brush, roller or airless gun in 2 layers. The second layer should be applied after the first one has dried, but within 24 hours of its application.
Consumption of EPOXYCOAT-S: 200-300 g/m2 per layer.
IV. REMARKS
Particular attention must be paid to the proper placement of the “special parts” of the pool, such as lights, water inflow and outflow points etc., which are vulnerable points as far as waterproofing is concerned.
EPOXYCOAT-S contains solvents. In cases of applications in closed rooms, measures should be taken for good ventilation.
Working time of epoxy systems decreases when ambient temperature rises.
Bonding between successive layers may be severely affected by the intervention moisture or dirt.
Epoxy layers should be protected from moisture for 4-6 hours after application. Moisture may whiten the surface or/and make it sticky. It may also disturb hardening. Faded or sticky layers in parts of the surface should be removed by grinding or milling and laid again.
In case that longer time than predicted interferes between the application of successive layers or in case that old floors are going to be laid again, the surface should be thoroughly cleaned and ground before application of the new layer.
Before application, study the safety advice mentioned on the product’s labels.