Concrete Tiles

 

Concrete tile roofs require regular maintenance to keep them looking at there best and water tight. Surface colour loss, erosion and tile brittleness are generally the result of a lack of maintenance, not storm damage. As the photos below demonstrate, concrete roof tiles DO need surface coating maintenance for both protection and appearance.

 

 

 

Weathered concrete roof in Brisbane

All colour is gone. Re-bedding and repointing is badly needed. Pits and holes are evident. Surface is eroded. Testing of a tile from this roof showed carbonation for the full depth in a random pattern.

 

This picture shows sand in the gutter from surface erosion on the tiles. Surface roughness. Pits and erosion are obvious. Maintenance has been neglected for years. From a grading of material taken from the gutter 84% was fine sand

 

 

 

The following questions and answers help explain typical problems and what can be done.

WHY SHOULD MAINTENANCE COATINGS BE APPLIED?

ü       To enhance the visual appeal of your roof

ü       To update the look of your house

ü       To ensure your roof remains in top condition and is water tight

ü       To extend the life of the tiles.

The coatings should be applied in three coats to cover the multi-facets of the tile profile

 

 

WHAT DO YOU MEAN BY "EXTEND THE LIFE OF THE TILES"?

  • Concrete tiles are not maintenance free and DO require specialised maintenance coating during their lifetime. They steadily deteriorate in time without maintenance, even just simple painting helps. Many tiles manufactured prior to about 1965 are particularly prone to accelerating deterioration.

 

My roof is only 10 years old does it REQUIRE MAINTENANCE?

  • A 10 year old roof may not require significant work but as part of a routine maintenance program for your house your tile roof should be inspected regularly. After 10 years the pointing may need renewing and you may have a few tiles that have cracked due to storm damage.

 

CAN THE COLOUR OF A ROOF BE CHANGED?

  • Yes. A colour change is a common reason for undertaking a full roof restoration. As your roof often accounts for 30% of the visual effect of your house it is important that the colour be kept up to date. Restyle can offer the latest colours as well as heat reflective coating materials in a variety of colours.

 

HOW LONG DOES THE "GLAZE" LAST?

  • The eventual breakdown of the factory applied "glaze" coating through exposure to ultra violet light and weathering takes about 5 years. This is normal and does not relate to either storm damage or defective product. "Glaze" is actually a misnomer. The material is correctly described as "sealant".

 

WHAT HAPPENS AFTER THE FACTORY APPLIED "GLAZE" WEATHERS AWAY?

  • The colour coating underneath starts to weather. This is very thin (maybe 1 millimetre thick). It is only on the surface not impregnated or right through the tiles (with few exceptions). We have found it common to see significant "bare" concrete exposed on roofs only about 20 years old.

 

WHAT HAPPENS AFTER THE ORIGINAL COAT WEATHERS AWAY?

  • "Bare" concrete is exposed on the roofs. Quite often concrete suffers from weak spots in the original mixture. These areas look like air bubbles on the surface of old concrete. They look like a hole left - as if a stone has dislodged from the concrete surface. Have a look at some old footpaths or concrete in your area. Sometimes this can be so bad that a hole actually "rots" right through the tile, especially in very old roofs. Don't panic though - this doesn't happen overnight. The state of weathering the roof has reached can easily be observed by close observation of the tiles' surface texture.

 

WHAT DO YOU MEAN BY "ACCELERATED WEATHERING?

  • Normal free atmospheric carbon dioxide reacts with accessible cement compounds in the tiles in a process known as carbonation. This carbonation causes reduced resistance to shock, brittleness and weathering (erosion) of the tiles. The extent of carbonation in concrete (and fibro) can be demonstrated by means of a very simple test that should be available through local civil engineers and concrete testing laboratories.

 

WILL SURFACE RESTORATION STOP CONCRETE TILE ROOFS LEAKING?

  • Probably, it depends on the source of the leak. Our estimator will conduct a full assessment to determine why your roof is leaking and recommend solutions.
  • Restyle can replace or repair any cracked tiles found. We can also repair pointing or complete a full re-bed and re-pointing of the ridge and hip caps if required.
  • Weathered concrete tiles can sometimes be porous - sometimes water goes through the tiles and drips down inside the house. This is rare and never storm damage. Surface restoration will seal the exposed tile surface. Old tiles treated with our TILECOAT process have been tested and exceeded the water permeability requirements of Australian standard A.S.1757. A very common cause of water entry is dirty and clogged water channels on the tile side laps. Maintenance roof cleaning prevents these leaks.

 

CAN HAIL REMOVE THE ORIGINAL GLAZE OR OXIDE COATS?

  • We have never seen a case where the damage could reasonably have been caused by hail. We have seen sealant delamination (glaze peeling) and premature oxide colour deterioration but nothing that is obviously hail induced. All local concrete tile roof manufacturers have occasional surface coating problems and all have crews spraying surface repair coatings. We have done this for local manufacturers ourselves.
  • We saw one 20 year old Monier concrete roof at Chermside that had weathered evenly to the point where the oxide was almost gone. Hail from the big January '85 Brisbane storm cleaned the already loose oxide from the spots where it struck and left the roof looking as if it was hail damaged. After we cleaned this roof the weathering was again obviously even - the signs of "hail damage" were gone.

 

ARE NEW CONCRETE ROOFING TILES ANY BETTER?

  • A clear distinction can be drawn between older concrete tiles (pre 1954 - 1970) and modern concrete roofing tiles. Modern tiles are made from precisely measured materials and are extruded. This results in a dense and homogeneous mixture which resists carbonation, water penetration and general weathering. However, modern tiles still require regular maintenance.

 

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