Let us first preview Metal long run.  There are many varieties of this, but people seem to class all as Coloursteel, which is one of many brands on the market.   Coloursteel is made by NZ Steel..


Metal/long run roof –


These are roofs made of sheet metal – corrugated through to ridge profile types.


The  Pros are:-

  • Can be very low pitch so more common due to height to boundary restrictions
  • Many looks and colours
  • Probably the cheapest to install

The Cons are:-

  • Most likely to fail on a restoration as the original paint coating is poor and pulls away easily
  • Prone to rust obviously and if this goes to far it needs replacing
  • Because of the nature of the fixings and flashings – once they degrade/rust – prone to leaking around these
  • Some dont like the sound of rain on the roof which is most prominent with this roof type
  • Can make for a hot house/roof space as the metal heats during the day.


Concrete tile roofs 

The next is a tiled roof

The Pros are:-

  • Easiest to restore and a restoration adds significant life to the roof with this substrate
  • Easy to change out damaged tiles – but old profiles are becoming hard to find
  • Thermally performs the best – takes time to heat up and cool down
  • Sound performance the best – cant hear the rain so much

The Cons are :-

  • As they get older they get more porous and more likely to crack or break – and then leak
  • They always leak – but with the advent of building paper underneath them – most water evaporates before causing damage
  • Prone to organic material build up – need regular moss treatments
  • Normally require a council consent to re roof if changing out to metal or PMT

The next tile we look at is


Decramastic  PMT (pressed metal tile) / /Gerard tiles –


These are metal tiles that can have a plain metal finish or commonly a textured finish with stone coating.

Here are the Pros :-

  • They restore very well – especially textured ones.
  • The metal is protected by the stone coat so are lasting 40-450 years before being restored
  • Easy to fix damage or rusted ones as you can change out individual tiles

Here are the Cons:-

Prone to organic build up – so moss treatments can be needed every 2-3 years

  • For a period in the 70’s/early 80’s they had an asbestos powder used and because of such need special treatment when being restored – all agents need to be aware of this – I can discuss this in more detail
  • Will dent if not walked on properly – and most people dont know how to walk on them! Dont let plumbers/Sky technicians/scaffolders …..or anyone walk on them apart from roofers!


And what about  this type of roof


Shingle roof


Shingles made of cedar or ashpalt


Here are the Pros:-

Look fantastic when new and cater for highly detailed roofs easily

  • Can easily change out individual shingles when damaged

Here are the Cons:-

  • Fade quickly and can look tired in a short time
  • Prone to being done cheaply and will leak if wooden substrate not up to spec
  • Cant be restored – need to be replaced
  • Prone to organic growth build up



Here is another type of roof.


Clay tile Roof.


Here are the Pros:-

  • Similar to Concrete in benefits


Here are the Cons:-

  • When old they get brittle and crack easily making them inappropriate for restoration as they cant be walked on
  • Other cons as per concrete

In terms of cost:

Metal roofs are the cheapest to do, followed by Concrete and the PMT/Decra roofs

In saying that, same size roofs of different substrate types will only vary by a few hundred dollars.

As each roof is different and will be in a different state of repair – the only way to get an accurate cost  is to get a signed quote which states exactly what will be done for the cost. ,..



For an average 3-bedroom single story house a restoration could be $5-9,000 (excluding health and safety systems) though you need to do your own research on the cost of your particular roof.

Make sure the person or company  quoting  undertaking the job inspects the roof thoroughly. That way there can be no excuse for them saying the cost was more because …….


If you accept a sight unseen quote you could be heading for  trouble.



In general, a restoration of any roof will be a third to a quarter the cost of a re-roof – and this percentage becomes smaller the bigger and more complex the roof


One company very experienced in re-roofing of houses is Kowhai Roof Coatings Ltd.   For their phone number ring  TopNotch Agents NZ Ltd  0800 355 655


TopNotch Agents  have a free service, helping Home sellers by identifying the  the best Real Estate Agents in NZ  and the one most suited to your area.  Phone 0800 355 655