Combining the most appropriate surface preparation, product selection, and Nutech Roof Coatings will guarantee a successful roof restoration ensuring an attractive and durable finish. The process developed and recommended by Nutech to correctly restore a roof involves the following steps:

STEP 1

Remove all broken tiles which may cause the roof to leak during cleaning. Chipped tiles with small corners broken or missing may be repaired and/or placed in the bottom row above the gutter.

STEP 2

It is essential that the roof surface is perfectly clean prior to painting.

On a roof badly effected by mould, moss, or lichen the application of Hypo Tile Cleaner is recommended. On very badly affected tiles saturate the surface with Hypo at approximately five square metres per litre using a knapsack sprayer, watering can, or chemical spray device. On surfaces less affected dilute the Hypo 1:1 with water prior to application.

WARNING: Hypo is a powerful chlorine bleach. Contact with skin and eyes must be avoided. Wash any contaminated clothing or skin immediately with copious amounts of water. Avoid breathing vapours. Seek immediate medical attention if swallowed. Refer to Nutech Material Safety Data Sheet for further information.

STEP 3

Check for internal vents and fans in the ceiling. By temporarily placing newspaper over these vents inside the roof space, the risk of damage due to dirty water during high pressure water cleaning is minimised. The light water spray which results inside the roof space during high pressure cleaning should not cause any damage.

WARNING: If the roof is connected to a water tank used for the collection of a domestic water supply for humans or animals it is important to disconnect supply pipes from the roof before chemical treatment, water cleaning, or re-coating. This prevents discolouration or foaming of water tank supplies.

After restoring the roof do not reconnect the water tank until a minimum of three moderate rains have removed any excess product or over-spray from the roof. Water for human consumption may be collected from roofs coated with Nuflex, Colourfast, Tileflex 2000, Waterproof Membrane, or Terraglaze.

STEP 4

Clean the roof using a high pressure water cleaner. A water cleaner operating at a minimum of 2000Psi is recommended. Care must be taken to avoid using excessive water minimising the possibility of damage. Precautions should be taken to avoid blasting dirty water over adjacent buildings, clothes lines, and cars.

STEP 5

Repair the bedding and pointing of all capping tiles and replace any damaged or badly rusted valley irons. Carefully inspect the tile battens and roof timbers to ensure the structure is sound. Replace or repair any damaged or suspect materials.

Remove loose capping tiles and re-bed in new cement mortar. A suitable mortar mix is:
One part builders cement, one part lime, and six parts fatty brick sand.
Mix with water, until these ingredients are a uniform colour and consistency.
To improve the adhesion and strength use one part NuBond to four parts water.

After the bedding is sufficiently cured replace all damaged tile cement pointing. A suitable pointing mortar mix is:
Flexipoint - precoloured ready-to-go flexible pointing compound.
or
One part General Purpose Cement to three parts sand.
(one part sharp sand and two parts brickies sand)
To increase pointing mix strength, adhesion, flexibility, and waterproofing;
Stir in one part NuBond to two parts water.
A small amount of oxide colourant may be added to the pointing mix
(approx. 5% of the cement weight is a good guide).

WARNING: Avoid using excess water in bedding and pointing mixes. If the mix becomes stiff never add additional water. Discard the mix and start again. Excess or post-added water will cause shrinkage, cracking, and white salt efflorescence which could affect coating colour and adhesion.

STEP 6

Apply one coat of primer or sealer having regard to the surface conditions. Refer to the guide below when selecting the appropriate coating, or investigate the wizard function elsewhere in our web page.

When restoring tiles, spray the tiles nose first and ensure complete coverage. It is important that the tile pointing is fully cured before any coating is applied.

Always allow sufficient time between coats especially as the seasons change. The longer the drying time the better the finish. In cold weather curing may take many hours, although at 25 Degrees Celsius the coating will normally dry in 30 - 60 minutes.

Do not apply under 10 Degrees Celsius, nor above 30 Degrees Celsius. Remember the tile temperature may vary by up to half as much again!

Avoid over-spray when spraying. Do not apply in high wind conditions.
Fibreglass roof sheeting, skylights, and newly painted guttering and spouting can be masked to avoid over-spray.

If Waterproof Membrane is used as the prime coat, additional curing time WILL be required due to the increased coating thickness.
If Anti-Corrosive Metal Primer is used, ensure the top coat is applied within three to four days to achieve maximum intercoat adhesion.

STEP 7

Apply two coats of the topcoat, as per selection from the following sections.

Always ensure that the primer is adequately cured before each new coat is applied. If multiple coats are applied without adequate curing time the potential for moisture damage due to rain, mist, or heavy dew is dramatically increased.

Applying the final coat in high temperatures may reduce coating gloss and affect adhesion.