How Much Does a Roof Restoration Cost?

• Replacing broken tiles and ridge caps

 With a professional roof restoration, usually any tile with a break in the corner that exceeds 50mm (and of course split tiles) should be replaced. Any damaged or broken ridge caps should also be replaced. Tiles with minor chips in them can be relocated to the blind side of the roof, as they only have an aesthetic impact and will not affect the weather-ability of the roof. With a less professional job, this simply isn’t done at all, or the breaks are just siliconed up. 

• Pressure cleaning the roof

 Pressure cleaning is critically important to ensure that the roof coatings do not peel off. Very high pressure, at least 4000psi, is required so that not only the dirt and dust is removed but also the pollutants that accumulate on suburban roofs. 

Particular attention needs to be applied to the nose areas, or the more vertical section of the tile near the overlap, as these areas get less sunlight and are quite prone to moss and lichen growth. If this area is not thoroughly cleaned, peeling of the coatings is almost inevitable.

With a less professional job, low power machines are often used, and this results in inadequate cleaning of the tiles. The noses of the tiles are not cleaned correctly which leads to peeling. When a more powerful machine is used, with an inexperienced operator, the homes often become flooded because the water is applied at an upwards angle in an attempt to clean the noses of the tiles. 

• Replacing rusted valleys 

The valley refers to the metal roof gutters that sit in between the opposing faces of your tiled roof. Any rust present needs to be either completely removed or the valley itself replaced. There are no products on the market today that can successfully treat or encapsulate rust. Anti-rust paints need to be put on to a surface that is completely free of rust, and rust converters are ineffective and the manufacturers do not offer a warranty. 

Valleys that are left with rust present in them will fail and cause the coatings to peel. With a less professional job, paint is applied directly onto rusted valleys or, at best, an anti-rust paint is applied over the top, which will have little or no benefit. 

• Re-bedding the ridge caps 

The bedding refers to the solid concrete positioned underneath the ridge caps. It’s often confused with pointing, which is actually the exterior application that is applied over the top of this solid core. If this material is cracking or crumbling, or the ridge caps are loose, it needs to be stripped out and re-done. Most homes over 10 years old will require at least a partial re-bed, but generally all ridge caps should be stripped away and a new foundation of concrete applied.

The mix of concrete is also very important. At least 25% cement should be utilised, and a good quality bricky sand used for additional adhesion. If this is not done, you can expect the restoration, particularly along the ridge lines, to fail within five years as a maximum. 

With a less professional job, the loose ridge caps and cracking and crumbling mortar is simply skimmed over and left unrepaired. In fact, with very inexpensive restoration jobs, the ridge caps are not touched at all, and the paint applied directly over the top of the old mortar. 

• Re-pointing the ridge caps

 The pointing material refers to the waterproof compound that is applied over the top of the bedding. It is designed to seal the ridge cap and prevent moisture ingress from affecting the concrete bedding compound. Historically, a cement mix and an additive with high elasticity was used to achieve this. In more recent times, a silicon type compound with a glassy sand is utilise for this task.

With less professional jobs, the pointing is either only partially done, or not attended to at all. In cases where it has been done, often just a coloured cement (high in water content) is sponged over the top of the bedding to give the appearance of a smooth surface. This is very brittle and will generally crack within a few years. 

• Applying a penetrative primer coat 

Concrete tiles can become porous on their surface. Applying a sealant or a paint directly onto the porous surface can trap air in the body of the tile. As the trapped air warms up, it can begin to expand and then contract again as it cools. This constant expansion and contraction over the years continuously pushes on the sealant or paint applied above. 

Inevitably, over time, the membranes will begin to bubble and peel. This is generally disastrous for your roof as nothing can be done to rectify badly peeling paint. Removing all of the paint can be virtually impossible, and applying wet paint over the top of peeling paint will just result in the wet paint peeling off as well.

For this reason, utilising a good primer that preferably incorporates both nanotechnology for deeper penetration, and high adhesiveness for superior bonding, is imperative. As a matter of fact, the application of a good quality primer can result in a coating that simply cannot peel. Weathering will eventually take its toll, but the actual coatings will be fused to the body of the tile. 

Providing the previous preparation steps are done correctly, your roof will only ever require a rinse down and a topcoat to keep up appearances. Less professional jobs do not apply a primer coating at all – every restoration job that hasn’t had a penetrating primer applied can be expected to fail (sometimes within six months but definitely within 10 years). 

• Applying a high solids sealer 

A sealer coat is a thick membrane that should be applied over the top of the penetrating primer. While this coat is not critical for longevity, it is essential to provide a superior finish for the topcoats. A good quality sealer coat should be very high on solids and is designed to be applied evenly over concrete tiles to minimise patchiness and ensure a smooth and consistent finish.

A less professional roof restoration will either not have a sealer coat at all, or it’ll have a sealer coat applied directly onto the tile surface without a suitable primer. Occasionally, a sealer is referred to as a primer/sealer – this term sounds like it could be adequate but is actually quite contrary. A primer penetrates and a sealer seals – it’s either one or the other, but never both. 

• Applying to UV resistant top colour coats 

The two top colour coats are the most important in terms of long-term aesthetic appeal. A compound that is a pure acrylic, with high grade UV stabilisers, cross linked polymerisation and good dirt pick up resistance is ideal for a quality long-term finish. Recent innovations in the roof coating industry have also led to titanium-based pigmentation which, while expensive, can last many times longer than a traditional roof paint. In fact, the manufacturers of these products generally warrant their materials for 20 years or longer. 

While you are doing your roofing research, it’s best to discuss this with the professional company you have selected. Some questions should be considered. How long will you stay in the house? Obviously the longer you stay in the home the more you may want to invest on your roof restoration to achieve a quality job to minimise inevitable ongoing expenses. If you’ll be in your home for five years or less, a more medium-grade restoration might be a better option as it should still be presentable upon the sale of your property. If you are selling in the very near future, you may not wish to overcapitalise on your investment.

A less professional roof restoration company will not go into too much detail about the coatings they are using. They will generally not ask any questions regarding your requirements and they almost never provide you with options. 

• The all-important cleanup

 Upon completion of work, the gutters and surrounds of the home should be thoroughly cleaned. The neighbours on either side of the property should be approached and asked if any dirt or roof related debris has entered their property. Roof restoration can be messy work, and the cleanup is a very important part of completing the job.

Less professional roof restorations will leave your home in a mess and your neighbours complaining. Over the years, we’ve found this is one of the issues that tends to irritate homeowners the most.