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Topic
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I’m on the EC of a 14-unit block in Sydney, on the Parramatta River. An experienced and I’m told well-regarded roofing firm has advised that the concrete roof tiles on our building should be re-coated to reinstate their original protective coating. It is stated this will extend their usable lifetime by at least 12 years (the period of the written guarantee from both coating supplier & the roofiing firm).
We have had problems in one section of roof due to leaks through cracked/broken tiles which lead to wet rot of the underlying battens, and anything which protects the approx 40-year old tiles from further deterioration or absorption of rain water should be to the good.
The broken tiles and rotted battens have been replaced, but because the original painted surface of the tiles has been weathered away the roofing contractor – and 2 members of the EC, who’ve had work done by the contractor in a house a year or ago and speak highly of the firm – state that this coating process is worth paying for. It will cost about $30,000, which is a lot for the reserve funds of a small block.
I’ve not been able to find any mention on the Forum or the site of others’ experiences with such coatings. I tried searching a lot of different keywords but came up with nothing.
I can mention the coating manufacturer’s firm, and if necessary the roofing contractor, but for the moment I’d prefer to just pose the question.
Does any flat-chatter have any experience or comments to offer?
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Sailor – so far as I’m aware concrete roof tiles don’t have a protective coating, and don’t need one because as they’re laid on a slope and overlap the rainwater just runs off them towards the roof gutter.
In my opinion, having a contractor climbing all over the roof of your building is likely to crack even more tiles, and the high-pressure washer that they use to clean them will likely provide the equivalent of many years normal weathering.
Paint won’t seal a cracked tile, so I’d suggest that you have any cracked ones that are visible from the street replaced with others from a less conspicuous part of the roof that are equally weathered, and replace those in that less conspicuous location with new tiles.
If your Owners Corporation wants to spend $30K to improve the aesthetics of the building for a few years, then by all means have it painted, but frankly if it’s aesthetics and longevity that’s the objective then look at replacing the entirely of the visible sections with a metal / colourbond™ roof.
I’m with Whale on this, if it ain’t broke, don’t fix it. There are a lot of cowboys out there in the roof restoration industry. It’s worth looking at the Monier website, according to it concrete tiles actually become less porous as they age.
Also look at the Whirlpool forums on the subject.
Whilst older rooves lose their gloss and street appeal, coatings and paints don’t usually last very long in such a harsh environment. Sure they look great for a few months or perhaps up to a year after application, but they start to break down after that and ultimately often look worse than if you left the roof alone in the first place.
Concrete tiles are not porous. A concrete tile will only leak if it is cracked. As DaveB has suggested, Whirlpool Forums are a source of opinions on this. I also found this document at WA Dept of Commerce.
I am inclined to agree about the lack of problem from old concrete tiles that have lost their glaze. Now that you have replaced the tiles that were actually cracked, can you monitor to check for any continued leaks? If there are no leaks you have fixed the problem for the cost of a few spare tiles.
Among our townhouses, all the tiles are weathered concrete from the 1970s. One unit had a recoating treatment done (in the ACT unit owners in townhouses (class B units) are responsible for maintenance of the unit) and it does not look good having one unit with a shiny new surface.
It might be worth looking for a business that sells recycled tiles in your area so you have a stock of spares. You will always get a few cracked tiles now and then. The tiles used at our set of townhouses are no longer available but they were common a few decades ago. A local business (in Queanbeyan, near Canberra) buys whole roofs of tiles and stockpiles them. These might come from demolished houses or they might come from extended houses where a set of uniform new tiles are put on both the new bit and the original bits of roof.
Anyway, we bought used, matching tiles when we extended our unit and the OC used the same used tiles when adding to our carports (over previously uncovered parking on common property). It looked much better than an instance of an owner who extended their unit with new tiles and it took many years for them to weather enough to blend in.