Cracked decramastic roof tiles - possible to replace DIY?

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Batman

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#177896 18-Aug-2015 10:40

Hi I have read 2 schools of thought on the net re decramastic roofs (70s). One says pointless to restore, just replace. The other says easy to restore with lasting results. I tend to believe the former. Am a few years before I can afford a new one I think.

Anyway, am told we have 17 cracked tiles ... and a healthy 4 figure sum to replace. I'd hate to spend that money and then find it still leaks (which I am guessing it will, at some stage)

Any alternatives? If I could find them i could try silicone, but if some already have silicone, so i presume you'd then have to remove the silicone to apply new ones?

MikeB4

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#1368463 18-Aug-2015 10:44

Decramastics are made of coated Galvanised iron, there are many companies around that recoat these but the roof may well be beyond its use by

Batman

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#1368476 18-Aug-2015 10:54

Apparently the roof is fine, just needs decoating and recoating. Which i am not too keen to believe...

grant_k

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#1368482 18-Aug-2015 11:07

I've never heard of a Decramastic Roof with cracked tiles. They either lose their coating, or rust out, or both, but don't generally crack.

Monier tiles, or similar concrete or clay tiles are the ones which crack. Are you absolutely sure you have Decramastic tiles?

If you do, and some have started to rust out then the rest won't be far away. We had a similar situation with a corrugated iron roof I wanted patched up. When I saw the iron coming off, I realised how flimsy it was, and only a matter of a short time before the water starting pouring through in countless places. In that situation, you are best to bite the bullet and go for a re-roof as it's only prolonging the inevitable.

Oh, and make sure you choose long-run iron or Monier tiles next time. Metal tiles are a pointless exercise IMO as they have so many points of weakness compared to long-run iron. Or, if it's the tile look you're after, go for Monier even though it may mean strengthening your purlins somewhat.

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#1368491 18-Aug-2015 11:22

Cracked metal suggests that they've been bent under pressure which is more likely to be localised, e.g. someone walking on them.

The life of a corrugated iron depends upon keeping the water from penetrating the exterior, preventing condensation on the interior and preventing kinks/cracks from walking on it - it's best to walk where it is fixed so you don't bend it. It's usually only about 2mm thick to start with so it doesn't take much rust to thin it. Even so it can last a long time. I've been keeping a retired relative's corrugated iron roof going for 30 years mainly by keeping on top of surface painting and removing visible rust. I've replaced almost every nail because they tend rust through before the roof gets holes in it.

Bung

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#1368493 18-Aug-2015 11:25

grant_k: . Or, if it's the tile look you're after, go for Monier even though it may mean strengthening your purlins somewhat.

I think the weight difference means the design from ground up has to be suitable.

timmmay

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#1368508 18-Aug-2015 11:36

My Mum had a big problem with her 70s tile roof, which didn't have any building paper underneath it as I understand. There was a slow leak, it ruined the lounge ceiling, it was fixed, the leak came back. The guy doing the fix was awful, unresponsive. She got it fixed but it was a lot of hassle.

Jase2985

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#1368541 18-Aug-2015 12:28

previous owner of our place just put the decromastic tiles over top of the old corrugated iron roof. Makes it a bit quieter when it rains.

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elpenguino

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#1368596 18-Aug-2015 13:35

Double skinning sounds great but I am led to believe you can get a bit of sweating in between which if trapped could led to corrosion problems.

Most of the posters in this thread are just like chimpanzees on MDMA, full of feelings of bonhomie, joy, and optimism. Fred99 8/4/21

mattwnz

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#1368622 18-Aug-2015 14:09

How about uploading a photo? As per another post, I haven't heard of cracked tiles, unless they are rusted through. Are you sure they aren't concrete or a composite? Anything that is cracked though will need replacing. The old press steel and chip coated roofs were prone to rusting, so maybe someone has just recoated over any old rusted one, which would likely mean a roof replacement. Go for longrun next time.

richms

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#1368628 18-Aug-2015 14:25

I have heaps that have cracked where they flexed from being walked on.

Horrible roofing system. Once repiled and the house is straight I will be changing to corogated longrun and seeing if they can add more of an overhang so the house looks less barn-like.

Richard rich.ms